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  • Potency of nanolay on structural, mechanical and gas barrier properties of poly(ethylene terephthalate) Nanohybrid
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-13
    Dipti Saxena, Karun Kumar Jana, Narendren Soundararajan, Vimal Katiyar, Dipak Rana, Pralay Maiti

    Thermoplastic and amorphous poly(ethylene terephthalate)/clay nanohybrids have been prepared through solution route. Organically modified NK75 nanoclay has been used as filler in different concentrations to enhance the properties. The Young’s modulus has increased significantly (66%) though there is slight reduction in toughness. Halpin Tsai and Hui-Shia models have been fitted well to explain the nature of stiffness for the prediction of the modulus values. Vicker hardness test has shown considerable improved hardness (16%) in nanohybrids and are nicely predicted using the modified rule of mixture model. The effect of uniaxial stretching on the structural development is explored through small angle X-ray scattering and wide angle XRD. The nanoclay has induced short range ordering upon stretching in nanohybrids as compared to pure PET. Nanoclay has induced high barrier for gas permeation in nanohybrids in comparison to pristine PET. Oxygen transmission rate has also been found to decrease up to 38% for using meager amount of nanoclay. The experimental permeability data has been fitted with different models and has been found suitable for its real applications.

    更新日期:2020-01-13
  • Oxygen-rich porous carbons from carbonyl modified hyper-cross-linked polymers for efficient CO 2 capture
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-13
    Yafei Sang, Gui Chen, Jianhan Huang

    A series of carbonyl modified hyper-cross-linked polymers (HCPs) with different porosity was prepared and they were carbonized for production of oxygen-rich porous carbons. The results show that these carbons have high Brunauer-Emmett-Teller (BET) surface area (440–1769 m2/g) and outstanding microporosity (72–87%), the oxygen is greatly improved after the carbonization with the oxygen content of 20.7–29.2 wt%. The CO2 uptake of PDVC-700-1 is the highest with the value of 303 mg/g at 273 K and 1.0 bar and PDV-pc has the highest CO2/N2 selectivity of 46.8. Interestingly, the CO2 adsorption is linear correlated to the ultramicropore volume (d < 1.0 nm) with the correlation coefficient of 0.9935 (273 K, 1.0 bar) and the O content also plays a role in CO2 adsorption. These porous carbons have medium adsorption heat (28.5–34.9 kJ/mol) with an excellent desorption and repeated use performance.

    更新日期:2020-01-13
  • Influence of pentaerythritol on the properties of polyvinyl alcohol films for the polarizers
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-11
    Sumei Zhang, Huiyang Yu, Qiang Chen, Haotian Hu, Yingxu Song, Jinyao Chen, Ya Cao, Ming Xiang

    Abstract Pentaerythritol was used as the plasticizer to prepare PVA films through solution casting method. The interaction between pentaerythritol and PVA was studied by FTIR. The crystallinity of raw PVA and modified PVA films was characterized by X-ray diffraction. The effect of the addition of pentaerythritol on the swelling properties, mechanical properties and optical properties of PVA films were investigated. The experimental results showed that the addition of pentaerythritol destroyed the hydrogen bonding in the PVA molecule and reduced the crystallinity of PVA. As the pentaerythritol content increased, the swelling property of the PVA films was significantly improved. The addition of pentaerythritol into PVA resulted in the increase of elongation at break, as well as the decrease of tensile strength. As the amount of pentaerythritol added, the optical performance of the PVA films was improved.

    更新日期:2020-01-13
  • Modified polypropylene/ thermoplastic polyurethane blends with maleic-anhydride grafted polypropylene: blending morphology and mechanical behaviors
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-11
    Ting An Lin, Mei-Chen Lin, Jan-Yi Lin, Jia-Horng Lin, Yu-Chun Chuang, Ching-Wen Lou

    Abstract This study proposes using polypropylene grafted maleic anhydride (MA) to improve the interfacial compatibility between modified impact-resistant polypropylene (MPP) and thermoplastic polyurethane (TPU). The melt-compounding and injection method is used to prepare MPP/TPU/MA blends. The blending morphology, tensile behavior, flexural behavior, and impact behavior of blends are evaluated in terms of the content of TPU and MA. The SEM images show the positive influence of using MA on the compatibility between MPP and TPU, and only 1 wt% of it can efficiently decrease the difference in polarity and interfacial tension. As MA is an additional reinforcement, 100 wt% of the blends are made of MPP and TPU, indicating that more TPU means less MPP. When the blends are made of more TPU, the tensile strength of the control group (pure MPP/TPU blends) shows a decreasing trend. By contrast, MPP80/TPU20/MA3 blends have a tensile strength of 28 MPa and Young’s modulus of 927 MPa, while MPP90/TPU10/MA1 blends have the optimal flexural stress of 53.99 MPa and flexural modulus of 1493.61 MPa. Exception for MPP60/TPU40/MA1 blends, all the other experimental groups have greater impact strength as a result of using 1 wt% of MA. Specifically, MPP90/TPU10/MA1 blends have the maximum impact strength of 105.28 J/ m. The addition of MA has proven to efficiently improve the compatibility and interfacial adhesion between MPP and TPU, thereby forming an extraordinary bonding with a stabilized phase where a stress can be efficiently distributed. This study expects to design and adjust the performance of the composite blends according to the test results of SEM observation, tensile strength test, and impact strength test.

    更新日期:2020-01-13
  • Mechanical and thermal properties of hyperbranched poly(ε-caprolactone) modified graphene/epoxy composites
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-11
    Lingran Hou, Jian Gao, Hong Ruan, Xu Xu, Shaorong Lu

    Abstract Graphene nanosheets (GNs) often results in incompatibility with the hydrophobic polymer matrix, and the tendency to form aggregates during processing. Herein, hyperbranched polycaprolactone modified GNs (PGNs) was obtained using 3,4,9,10-perylenetetracarboxylic acid anhydride (PTCDA)reacted with GNs and caprolactone. Firstly, π-π stacking interactions between GNs and perylenebisimide derivatives (PBI), and then in-situ polymerization of ε-caprolactone. The structure and characteristic of PGNs were investigated by infrared spectroscopy, wide angle X-ray diffractometry, thermogravimetric analysis and ultraviolet spectrum. PGNs was added into epoxy matrix at different contents to improve the mechanical and thermal properties of epoxy. At 1.0 wt.% PGNs content, the impact strength and tensile strength of PGNs/epoxy composites were 43.41 kJ/m2 and 91.60 MPa. Compared with those of pure epoxy, these value increased by148% and 87%, respectively, as well as the Tg increased by about 20 °C.

    更新日期:2020-01-13
  • The compatibilization of PLA-g-TPU graft copolymer on polylactide/thermoplastic polyurethane blends
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-11
    Xian-Zhong Mo, Fu-Xiang Wei, Deng-Feng Tan, Jin-Ying Pang, Chun-Bo Lan

    Abstract The insufficient compatibility between poly(lactic acid) (PLA) and thermoplastic polyurethane (TPU) phase leads to some disadvantages such as extrudate swell and poor mechanical properties of PLA/TPU blends. Therefore, to improve the compatibility is an essential work of modifying the blends. In this study, PLA, dicumyl peroxide (DCP), glycidyl methacrylate (GMA) and TPU were added to torque rheometer in sequence to synthesize PLA-g-TPU graft copolymer, and the synthetic products were characterized by nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared (FTIR) spectra. Subsequently, binary blends (PLA /TPU blends) and ternary blends (PLA/TPU/PLA-g-TPU blends) were prepared via melt blending in twin screw extruder. The compatibility, the extrusion behavior, thermal stabilities and mechanical properties of binary blends and ternary blends were studied, respectively. The results showed that the graft copolymer played a crucial role in improving the compatibility of PLA/TPU blends. In comparison to binary blends, the ternary blends exhibited better extrusion behavior and higher thermal stabilities. In addition, the notched impact strength and elongation at break of blends improved under the effect of the graft copolymer. Interestingly, the tensile strength also strengthened with incorporation of the graft copolymer, which indicated that the interfacial adhesion between PLA phase and TPU phase had been enhanced.

    更新日期:2020-01-13
  • New TEMPO containing polymers for all polymeric oxidation procedure
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-08
    Perihan Öztürk, Ece Ayça Yücel, Akın Akdag

    2,2,6,6-Tetramethylpiperidine 1-oxyl (TEMPO) is a versatile compound which is used mainly in organic oxidation reactions and organic battery applications. Incorporating TEMPO into a polymer could provide many applications into its repertoire. In this study, new polymeric TEMPO derivatives are synthesized and characterized to be used as catalysts in the presence of another polymer which constitutes N-halamine functionality. These polymeric mixtures were superior since the mixture could easily be separated from the reaction medium by simple filtration and reused in some other oxidation reactions numerous times. In turn, an all polymeric oxidation method was developed for oxidation of primary alcohols.

    更新日期:2020-01-08
  • Effect of the diameter of MWCNTs on shape memory and mechanical properties of polyurethane composites
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-08
    Krishan Kumar Patel, Rajesh Purohit, S. A. R. Hashmi, Ritesh Kumar Gupta

    Abstract The work reported herein, effect of diameter of reinforced (MWCNTs) on shape memory and mechanical properties of shape memory thermoplastic polyurethane (SMTPU) composites. The composites containing 1 wt.% reinforced having three different MWCNTs outer diametre (OD = 10–20 nm, OD = 30–50 nm, and OD= > 50 nm) with the same length (10–30 μm) were prepared through melt mixing route by using micro-compounder followed by Injection moulding. Shape memory and mechanical properties both were significantly improved for composites. Thicker MWCNTs (at same length) leads to a less number of MWCNTs at a given wt.%, result in less percolated network and larger distance between the indivisual MWCNTs which alter the shape memory and mechanical properties. Furthermore, with increasing the diameter of reinforced MWCNTs at a same wt.% in polyurethane matrix the properties were decreased.

    更新日期:2020-01-08
  • Correction to: Preparation and characterization of renewable composites from Polylactide and Rice husk for 3D printing applications
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-06
    Chi-Hui Tsou, Wei-Hua Yao, Chin-San Wu, Chih-Yuan Tsou, Wei-Song Hung, Jui-Chin Chen, Jipeng Guo, Shuai Yuan, Ehua Wen, Ruo-Yao Wang, Maw-Cherng Suen, Shi-Chih Liu, Manuel Reyes De Guzman

    The original version of this article unfortunately contained a mistake. The name "Maw-Cheng Sunn" should be corrected to "Maw-Cheng Suen".

    更新日期:2020-01-06
  • Thermomechanical and viscoelastic properties of green composites of PLA using chitin micro-particles as fillers
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-04
    Mohammad M. Hassan, Kiyohito Koyama

    Many thermoplastic biocomposites made with non-biodegradable polymers as a matrix polymer are not biodegradable. In this work, biodegradable polylactide (PLA)/chitin micro-particle composites were successfully prepared by melt blending without using any compatibilizer or processing aid. The effects of the addition of chitin micro-particles to PLA on its thermal stability, physicomechanical properties and microstructures were evaluated by thermo-gravimetric analysis, dynamic mechanical thermal analysis, differential scanning calorimetry, tensile strength measurement, and scanning electron microscopy. It was found that the addition of chitin micro-particle to PLA increased the stiffness, tensile strength, and hydrophobicity of PLA but negatively affected its thermal properties and elongation. The tensile strength exhibited by the pristine PLA was 41.5 MPa, which increased to 48.5 for the chitin loading of 3% but a further increase in the chitin loading resulted in a reduction in tensile strength. The increase in chitin loading resulted in an increase in stiffness of PLA as the storage modulus increased from 3.21 GPa for the neat PLA to 3.48 GPa for the PLA loaded with 3% chitin microparticles. The results show that chitin can be used for the reinforcement and also to enhance the moisture barrier properties of PLA.

    更新日期:2020-01-04
  • Effect of copper (II) nitrate 3H 2 O on the crystalline, optical and electrical properties of poly(vinyl alcohol) films
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-03
    R. S. Hafez, S. El-Khiyami

    Composite films of poly (vinyl alcohol) PVA doped with various weight ratios of Cu(NO3)2.3H2O (0, 1, 5, 10 and 20) wt% have been prepared by solution casting method. Using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Ultraviolet–Visible (Uv-Vis) spectroscopy, the synthetic composites were analyzed. The findings showed that Cu(NO3)2.3H2O interacts with the hydroxyl group present in PVA chain. The XRD analysis revealed that after adding Cu(NO3)2.3H2O, PVA crystallites were destroyed. With increasing Cu(NO3)2.3H2O ratio, the absorbance of composite samples increased. The optical band gap energy of the composite samples was calculated using Tauc’s formula and it reduced by increasing dopant concentration. The dielectric modulus and ac conductivity of the composite films have been studied. Ac conductivity was found to increase by increasing the dopant concentration up to 10 wt%. Electrical conduction is carried out using correlated barrier hopping model.

    更新日期:2020-01-04
  • Structures and dynamics of polyethylene nanostructures with different free surface geometries: nanofilm, nanofiber and nanoparticle
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-03
    Visit Vao-soongnern

    Monte Carlo simulations of coarse-grained polyethylene (PE) models were used to compare structural and dynamic properties of polymer chains confined at the nanoscale with different free surface geometries i.e. nanofilm, nanofiber and nanoparticle. All polymer nanostructures, which contain 95 chains of C100H202 were generated by serial reduction of the periodic boundary conditions. For all these nanostructures, the density profiles are hyperbolic, with end bead segregation at the surface. Bulk densities, sizes (thickness/radius) and the interfacial widths are lower, larger and broader for nanofilm, nanofiber and nanoparticle, respectively. The local environment of bond orientation is isotropic in the middle of these nanostructures, but becomes anisotropic near the surfaces. Chain orientation at the surface is also observed and the degree of anisotropy at the whole chain is nanofilm > nanofiber > nanoparticle. Surface energies are calculated directly from the on-lattice energetics and their magnitudes are: nanofilm < nanofiber < nanoparticle. The mobilities of polymers in the nanostructures at the level of bond and chain scales are greater for nanofilm > nanofiber > nanoparticle along the direction of periodic boundaries but this order is reversed for the diffusion along the direction normal to the free surfaces.

    更新日期:2020-01-04
  • Surface modification of sepiolite: effects on thermomechanical properties of PP/PA6 blends
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-03
    Kui Wang, Jie Xie, Tiantian Li, Xianshun Wu, Weijiang Huang, Qin Tian, Chunyun Tu, Wei Yan

    Abstract In the current work, organosepiolite (O-Sep) was prepared via modification of sepiolite (Sep) with silane coupler γ-methacryloxypropyltrimethoxysilane (CG-570) and polypropylene (PP)/ polyamide 6 (PA6) blends were introduced to investigate the effect on thermomechanical properties of polymer-based nanocomposites. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and rotational rheometer were employed to characterize the morphology and thermomechanical properties of materials. The results show that O-Sep improved the dispersion of PA6 in the PP matrix and enhanced both the mechanical behavior and thermal properties of the PP/PA6/O-Sep nanocomposites.

    更新日期:2020-01-04
  • Synergistic reinforcement of waterborne polyurethane films using Palygorskite and dolomite as micro/nano-fillers
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-02
    Lingli Ni, Yu Mao, Yongtao Liu, Peng Cai, Xiaowu Jiang, Xiaoyan Gao, Xiaochun Cheng, Jing Chen

    Abstract In this paper, two types of reinforcement agents of fibrous palygorskite (PAL) and rhombohedral dolomite (DOL) have been used together by simply mixing in order to improve the mechanical and thermal properties of waterborne polyurethane (WPU). A great synergistic effect between 1D PAL and 3D DOL on reinforcing WPU matrix has been observed. In comparison to neat WPU, the tensile strength of such three components WPU-based composite has been significantly improved by 178% with an addition of 4 wt% PAL and 6 wt% DOL. Furthermore, its initial decomposition temperature also has been increased 55 °C. The formation of 3D conjugated filler network with 1D PAL inserted into the 3D DOL network could be attributed to such synergistic reinforcement of WPU. This work provides a good example and eco-friendly pathway for the preparation of high performance polymer composites by simply using micro/nano-fillers with different dimension together.

    更新日期:2020-01-04
  • Synthesis, characterization, thermal stability and kinetics of thermal degradation of novel polymers based-s-triazine Schiff base
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-06
    Hessa H. Al-Rasheed, Sayed Z. Mohammady, Kholoud Dahlous, Mohammed R. H. Siddiqui, Ayman El-Faham

    The present work represents the synthesis of five new s-triazine based Schiff base polymers via condensation polymerization process between bishydrazino-s-triazine derivatives and terephtaldehyde. The prepared polymers were characterized by different techniques (FTIR, UV-Vis, TGA, XRD and DSC). The new polymers showed good thermal properties and good values for the Limited Oxygen Indexed (LOI) 22.74, 27.36, 30.52, 24.38, 21.39 for polymers 5a-e; TP-DHBT, TP-DHMBT, TP-DHMT, TP-DHPT, and TP-DHMeT, respectively. Accordingly, these types of polymers could be classified as flame-retardant and self-extinguishing polymers. The Tg values of the polymers 5a-e varied in the range from 191.4 to 241.1. The effect of substituent in the triazine ring has great impact on the properties of the polymers 5a-e as observed from the DSC and XRD results. Moreover, the thermal degradation kinetics of two selected polymers with higher thermal stability (5b and 5c) from the prepared series was studied using the method of Friedman. The behavior of activation energy is found to be highly dependent on the polymer molecular structure.

    更新日期:2020-01-04
  • Synthesis of N-benzyl-2-(dodecylthio)-N-(2-(dodecylthio)ethyl)ethanamine: new ligand for block copolymerization of styrene and methyl methacrylate using ATRP
    J. Polym. Res. (IF 1.53) Pub Date : 2020-01-02
    Hassan Hajifatheali, Ebrahim Ahmadi, Mohamadreza Marefat

    Abstract In this study polystyrene and polystyrene-block-poly (methyl methacrylate-co-styrene) were synthesized by atom transfer radical polymerization (ATRP) method using a new synthesized ligand, N-benzyl-2-(dodecylthio)-N-(2-(dodecylthio)ethyl)ethanamine (SNS), which is tridentate ligand with mixed donor atoms. To overcome the poor initiation efficiency of polystyrene during chain extension with methyl methacrylate, use was made of halogen exchange and a small amount (10%) of styrene in the second block of the copolymer. The use of the aforementioned yielded well-defined polymers with controlled high molecular weights and narrow molecular weight distributions (Mn = 52,200, PDI = 1.45). The synthesized polymers were carefully characterized via FT-IR, 1H NMR, 13C NMR, and GPC techniques. Finally, the synthesized polystyrene and block copolymer were compared in terms of water contact angle.

    更新日期:2020-01-02
  • Synthesis of new azo dye polymers based on naphthol by oxidative polycondensation: antimicrobial activity and fastness studies
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-08
    Dilek Çanakçı, Selahattin Serin

    Azo dye polymers were synthesized by an oxidative polycondensation reaction of naphthol based azo dyes with the oxidants NaOCl in an aqueous alkaline medium. These synthesized azo dye polymers were characterized by UV-Vis, FT-IR, 1H NMR techniques. The surface morphology of the azo dye polymers was understood by Scanning Electronic Microscopic study(SEM). The changes in weight in relation to change in temperature of synthesized compounds the was studied by TGA/DTA analysis. All the novel polymers were characterized to determine molecular weights by gel permeation chromatography(GPC). All of the azo dye monomers and polymers were researched for antibacterial (Corynebacterium xerosis, Bacillus brevis, Bacillus megaterium, Bacillus cereus, Mycobacterium smegmatis, Staphylococcus aureus, Micrococcus luteus Enterococcus faecalis, Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Yersinia enterocolitica) and antifungal (Kluyveromyces fragilis, Saccharomyces cerevisiae, Candida albicans) activities. When results of antibacterial activity of synthesized compounds was compared with standard Ampicillin, Streptomycin Sulfate, Nystatin. ıt is seen that the azo dye monomers had good antibacterial activity whereas the azo dye polymers did not have as good activity as the monomers. The dyes were examined in respect of their washing, water, sweat (acid and base) and frictional (dry and wet) fastness. From the results, It was found that The fastness properties of the azo dye monomers are better than the polymers. Because the bonding ability to the fabric in the monomers is better than the long chain polymers having a high molecular weight.

    更新日期:2019-12-30
  • Spectroscopic and mechanical properties of PVC plasticized by bio-plasticizer ESO
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-08
    Azeddine Rouane, Djamal Zerrouki, Michel Aillerie, Abdellah Henni

    Abstract In this work, we describe the synthesis of epoxidized sunflower oil (ESO) and its incorporation as a bio-plasticizer of PVC by the partial substitution of bis (2-ethylhexyl) phthalate (DEHP). The formulations are based on PVC and a plasticizer binary system (ESO/DEHP) varying from (00/60) Phr to (30/30) Phr. The epoxidation of the sunflower oil gives an oxyrane oxygen (O.O) in order of 6.2%. The optical properties of the so-obtained PVC formulations (ESO) are experimentally characterized by infrared Fourier transformer (FTIR) and Ultraviolet Visible (UV-Visible). The mechanical properties are determined using the tensile strength, Hardness shore D and A. The results show that after a partial substitution of DEHP by ESO (up to 20 Phr), the films maintaining the suppleness of the PVC and without reaching a stage of thermal degradation.

    更新日期:2019-12-27
  • Effect of the synthesis solvent in swelling ability of polyacrylamide hydrogels
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-19
    Amal El-Halah, Nain González, Jesús Contreras, Francisco López-Carrasquero

    Abstract A series of polyacrylamide hydrogels (PAAm HGs) and polymers were synthesized by free radical polymerization in the same reaction conditions but using two different media as solvent: water/ethanol at 100/0, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, and 20/80 (V/V) and water/DMSO at 100/0, 90/10, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70 and 20/80 (V/V). In most cases hydrogels were obtained in high yields and their swelling degree showed a significant dependence with the solvent used in the synthesis. When HGs were synthesized in water/ethanol mixture, the maximum equilibrium swelling (Seq) was reached when the water/ethanol ratio was 60/40(V/V), while for water/DMSO it was obtained for a water/DMSO ratio 80/20. In both cases, these swelling values were higher than when the HGs were synthesized in pure water. The swelling degree achieved by the HGs in water/ethanol was directly related to the yields and the pore size, but this behavior was not observed for the HGs obtained in water/DMSO. In all cases the HGs obtained in water/DMSO swell more than those obtained in water/ethanol. On the other hand, the molar mass of the PAAm polymers prepared in the same reaction conditions, decrease as the proportion of ethanol or DMSO increase. However, the molar mass reached by the polymers obtained in water/DMSO were higher than those obtained in water/ethanol.

    更新日期:2019-12-19
  • Physico-chemical based mechanistic insight into surfactant modulated sodium Carboxymethylcellulose film for skin tissue regeneration applications
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-17
    Muhammad Ali, Nauman Rahim Khan, Hafiz Muhammad Basit, Saima Mahmood

    Skin tissue regeneration scaffolds represent a promising field of research focused on formulation and optimization of cost-effective extracellular matrix based on natural polymers. Sodium carboxymethylcellulose is one of the most widely studied and least expensive natural polymers for fabricating film formulations aiding in skin tissue regeneration process the following damage, but its hydrophilicity contributes to its failure to prevent loss of excessive moisture from wound, low adsorb-ability, less mechanical strength, and rapid erosion. This study aims to develop a surfactant modified sodium carboxymethylcellulose-based films addressing the needs for skin wound healing applications. Sodium carboxymethylcellulose films were developed with varying concentrations of tween 80 in the range of 0.05 to 0.5% w/w and subjected to various physicochemical characterization tests like adsorption, moisture uptake, erosion, water vapor transmission, and water vapor permeability rate, vibrational, thermal and morphological analysis. The results indicated that the formulation containing 0.3% w/w of tween 80 was able to form films with a significant-good adsorb-ability, reduced percent erosion and high tensile strength with the formation of “folds” in the film surface. The vibrational and thermal analysis revealed fluidization of hydrophilic as well as hydrophobic domains which was attributed to the development of new “bonding” between the polymer and surfactant and/or plasticizer moieties in the formulation which though didn’t affect the transition temperature but significantly reduced the energy to induce transition which is envisaged to increase the elasticity of the film. This optimized combination of polymer and tween 80 may play an effective role in hastening skin regeneration process following damage. Sodium carboxymethylcellulose films with added 0.3% w/w tween 80 represent an ideal combination for the fabrication of sodium carboxymethylcellulose.

    更新日期:2019-12-18
  • The influence of organic modified montmorillonite on the solution properties of copolymer containing β-cyclodextrin
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-14
    Xu Hu, Yangchuan Ke

    In this paper, organic modified montmorillonite (O-MMT) was successfully encapsulated in acrylamide (AM)/cetyl dimethyl allyl ammonium bromide (SD-16)/modified β-cyclodextrin (M-β-CD) copolymer (denoted as ASM) by in situ polymerization. The ASM/O-MMT nanocomposite was characterized by FT-IR and TGA. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) clearly proved the exfoliation/intercalation phenomena of O-MMT in the ASM matrix. The results indicated that the introduction of the O-MMT endowed the ASM with excellent thickening efficiency, temperature resistance, salt tolerance, shear resistance. The viscosity retention rate of ASM/3 wt% O-MMT at 90 °C was 55.3%, which was higher than that of pure ASM (30.9%). The ability of salt tolerance for ASM/3 wt% O-MMT nanocomposite (Na+: 40%, Ca2+: 41.3% and Mg2+: 42%) were superior to that of ASM (Na+: 18.9%, Ca2+: 21.3% and Mg2+: 20.7%). Besides, measurement of the viscoelasticity revealed that the addition of the O-MMT significantly improved the storage modulus (G’) and loss modulus (G”) of ASM, which could be attributed to the O-MMT sheets in the ASM act as physical crosslinkers between macromolecules. These results indicated that ASM/O-MMT nanocomposite was more suitable for enhancing oil recovery.

    更新日期:2019-12-17
  • Self-healing high-performance thermosets utilizing the furan/maleimide Diels-Alder and amine/maleimide Michael reactions
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-14
    Kanami Yasuda, Kaito Sugane, Mitsuhiro Shibata

    The reaction of furfurylamine (FA) and 4,4′-bismaleimidodiphenylmethane (BMI) at a molar ratio of 2/1 generated a product (FABMI) mainly composed of 4,4′-bis(2-furfurylaminosuccinimido)diphenylmethane. Mixtures of FABMI, BMI and p-xylylenediamine (XDA) at FABMI/BMI/XDA molar ratios of 1/3/1, 2/4/1, 1/4/1 and 2/6/1 were prepolymerized at 120 °C, hot-pressed at 130–140 °C, and then annealed at 60 °C to produce cured products. The FT-IR analysis revealed that the Michael addition and Diels-Alder (DA) reactions occurred for all the cured products. FABMI-BMI-XDAs with relatively low feed FABMI mass fractions displayed excellent 5% mass loss temperatures higher than 400 °C. The cured product with the highest feed XDA mass fraction exhibited the highest flexural strength, modulus and strain at break among all the cured products. Onset temperatures of the endothermal retro DA reaction for the cured products were in the ranges of 140–150 °C. All the cured products were at least twice healed by the thermal treatment at 150 °C for 20 min and then 60 °C for 48 h.

    更新日期:2019-12-17
  • Cyclopentadithiophene and Diketo-pyrrolo-pyrrole fused rigid copolymer for high optical contrast electrochromic polymer
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-13
    Kanpitcha Jiramitmongkon, Chuleekorn Chotsuwan, Udom Asawapirom, Pussana Hirunsit

    Two donor-acceptor electrochromic copolymers containing fused rigid units of cyclopentadithiophene and diketopyrrolopyrrole, namely PCPDTT-DPP with benzene and thiophene ring linkers, were successfully synthesized. The electrochromic properties of the copolymers were characterized by cyclic voltammetry, UV-Vis spectroscopy and spectroelectrochemical method. The results demonstrated that the effect of DPP on the copolymer showed the p-type doping with an electrochemical band gap of 1.45 eV. The copolymer showed a higher color contrast changing from purple to transparent with %ΔT of 55% at ±1.0 V vs. Ag/AgCl compared to the parent polymer containing only cyclopentadithiophene unit. The results indicated that the new copolymer could be a potential candidate for electrochromic materials in smart films and windows.

    更新日期:2019-12-17
  • Comparative biodegradation study of polymer from plastic bottle waste using novel isolated bacteria and fungi from marine source
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-12
    Rwiddhi Sarkhel, Shubhalakshmi Sengupta, Papita Das, Avijit Bhowal

    The yearly worldwide interest in using polymers reliably expanded over the ongoing years. The marine plastic pollution is increasing because of the plastic wastes thrown into the shallow sea outrageously. In the present study, biodegradation of synthetic polymers obtained from Plastic bottle waste, has been carried out. In this experimental study, bacterium and fungus was isolated from the marine environment and was used for degradation of plastic waste strips. The degraded polymer films were critically evaluated by the following characterization methods like Weight loss, FTIR, SEM and XRD. The results indicate that the polymers from plastic bottle waste sample showed 35% degradation using bacterial strains and 22% using fungal strains in a time period of 6 weeks. Different parameters varying temperature, pH, inoculum dosage concentration was also assessed which signified that Plastic bottle waste treated by bacteria gives a better result compared to fungal degradation.

    更新日期:2019-12-13
  • Poly(1,6-heptadiyne)/ABS functionalized microfibers for hydrophobic applications
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-11
    Pawan Kumar, Prakash M. Gore, RaviPrakash Magisetty, Balasubramanian Kandasubramanian, Raja Shunmugam

    We report an electrospun & thermally stable micro-fibers of poly(1,6-heptadiyne) (PHD), modified with ABS. Developed micro-fibers demonstrated hydrophobicity (WCA~145o ± 2o), and exhibited hierarchical surface morphology (confirmed by FESEM analysis). Simulation study showed Chi parameter i.e. χc = 7.88, & free energy of mixing i.e. 4.67 kcal/mol, thereby demonstrating its feasibility for electrospinning. PHD/ABS microfibers demonstrated low ice-adhesion ability, where, it effectively removed frozen water droplets in 8 s from hydrophobic surface, under an air-stream rate of 78 kPa/s. High thermal stability (200 °C), hydrophobicity and low ice-adhesion ability, demonstrate that PHD/ABS microfibers can be effectively used for multifunctional engineering/industrial applications.

    更新日期:2019-12-11
  • Analysis and modelling of the media influence on short fibre reinforced amorphous thermoplastics
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-11
    Simon Koch, Christian Hopmann

    The contact of plastic components and media in use is often unavoidable. In addition to the influence of the medium on the mechanical properties, the occurrence of environmental stress cracks (ESC) is one of the most frequent causes of failure of plastic components in use. A significant improvement in the durability of plastics under the influence of the medium using a fibre reinforcement was shown in preliminary tests. But so far, there have been no fundamental investigations in the literature on this topic. The presented investigations deal with the influence of media on the mechanical behaviour and the occurrence of stress cracks under consideration of fibre reinforcement and its orientation. Therefore, a new test bench as well as tensile tests under media influence accompanied by acoustic emission measurement were used. Various media in combination with polycarbonate and polystyrene were investigated. Furthermore, a multiscale simulation based on molecular dynamics simulation as well as process and structure simulation was developed and validated.

    更新日期:2019-12-11
  • Surface improvement effect of silica nanoparticles on epoxy nanocomposites mechanical and physical properties, and curing kinetic
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-10
    Arash Kamran-Pirzaman, Yaser Rostamian, Sahra Babatabar

    In this paper, surface modification was performed on silica nanoparticles using 3-aminopropyl trietoxylsilane (APTES) and surface changes of nanoparticles were investigated using TEM and FE-SEM imaging. Furthermore, its physical and mechanical properties were investigated by building three samples including pure epoxy, epoxy/unmodified nano silica, and epoxy/modified nano silica with weights of 1, 3 and 5% of the nanoparticles to the whole system (epoxy and hardener). The results show that the modified nanoparticles were well dispersed in an epoxy matrix, and elastic modulus has improved. For example in a sample with 5% weight percentage of nano silica, the tensile elastic modulus, yield stress, and failure strain are increased by 77%, 124%, and 32%, respectively. Since the epoxy curing process is an important factor that affects the performance of the cured epoxy, curing process samples were analyzed using DSC. Also, various methods of activation energy were measured at the appropriate kinetic model. The reaction rate equation was obtained for each sample. The modified particles reduce the activation energy of the process compared to the two epoxy and epoxy/unmodified nano silica.

    更新日期:2019-12-11
  • A new coordination polymer for selectively detect TNP and its inhibition activity on P.gingivalis growth by reducing ragA and ragB gene expression
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-02
    Xu Wang, Dai-Qing Li, Jun Zhao, Chao Wei

    A four-fold interpenetrated Zn(II)-based coordination polymer with the chemical formula of {[Zn2(L)2(bdc)]·(H2O)2·DMF}n (1) was synthesized by solvent method using terephthalic acid (H2bdc) and N1,N1,N4,N4-tetrakis(4-(1H-imidazol-1-yl)phenyl)benzene-1,4-diamine (L) as the mixed ligands. The as-prepared complex 1 was measured via the elemental analysis and single crystal X-ray diffraction. Furthermore, due to its strong intense emission, complex 1 could be applied as luminescent sensor to sensitively detect 2,4,6-trinitrophenol (TNP), which has the characteristics of high sensitivity and selectivity. In addition, to evaluate the anti-bacterial effect of compound 1 in vitro, the P.gingivalis growth curves were measured. And the relative expression of ragA and ragB was detected by RT-PCR to reveal the mechanism of the compound in the anti-infectious activity. The potential anti-infectious criteria that has been observed in the experimental measurement has been further studied by using molecular docking technique.

    更新日期:2019-12-11
  • Facile one pot synthesis of strong epoxy/agar hybrid hydrogels
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-02
    Masihullah Jabarulla Khan, Qipeng Guo, Russell Varley

    Epoxy biopolymer hybrid hydrogels have excellent potential for load bearing applications, despite limited studies in this area. In this paper, a facile one-pot synthesis of epoxy/agar hybrid hydrogels has been reported. Infrared spectroscopy, rheometry, thermal, mechanical properties and immersion studies have been reported. An advantage of the hydrogels synthesized here is that they can be prepared in a shorter timeframe than conventional epoxy biopolymer hydrogels. Diethylene triamine was used as the cross-linker which induces gelation within five minutes at 90 °C. The mechanical properties of epoxy hydrogels prepared using diethylene triamine are found to be comparable to that of hydrogels prepared using long chain amine terminated poloxamers. The compressive toughness of the hybrid hydrogels increases by ~380% via the addition of 3 wt% agar in comparison with epoxy hydrogels. These hybrid hydrogels are elastic and biodegradable.

    更新日期:2019-12-11
  • Synthesis and properties of processable poly(benzimidazole-imide)s based on 2-(3-aminophenyl)-5-aminobenzimidazole
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-02
    Yang Jiao, Guofei Chen, Haijun Zhou, Feng Zhang, Xiaoqi Chen, Yantao Li, Xueshan Xiao, Xingzhong Fang

    A series of poly(benzimidazole-imide)s (PBIPIs) derived from different dianhydrides and 2-(3-aminophenyl)-5-aminobenzimidazole (m-BIA) were synthesized via thermal imidization to form flexible films. This series of PBIPIs showed great Tgs ranging from 296 to 484 °C, excellent thermal stability performed in 5% weight loss temperatures (Td5%s) of 502–529 °C in N2 and good mechanical properties (tensile strengths of 89–127 MPa, tensile moduli of 2.9–4.1 GPa and elongations at break of 3.9–6.9%). Compared with PIs derived from 6-amino-2-(4-(4-aminophenoxy)phenyl)-1H-benzimidazole (p-BIODA), m-BIA based PBIPI films exhibited higher Tg, and better solubility. Besides, the thermoplastic PBIPI resin (PI-6-PA) derived from 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) and m-BIA exhibited good melt processability with high Tg of 273 °C, melt flow index (MFI) of 7.76 g/10 min, minimum complex viscosity of 11.9 × 103 Pa·s at 402 °C and low melt viscosity ratio of 2.46 at 400 °C.

    更新日期:2019-12-11
  • A review on Copoly(ether-ester) elastomers: degradation and stabilization
    J. Polym. Res. (IF 1.53) Pub Date : 2019-12-02
    Eid M. Alosime

    This review focuses on the possible mechanisms of thermal or thermo-oxidative degradation of the copoly(ether-ester) elastomer (COPE) reported in formed literatures. The ester group, apart from the other functional groups, can occur in both hard and soft segments. The lifetime of the COPE is controlled by both oxidation and thermal degradation processes, which mostly proceed independently. The thermal oxidation of ester elastomers may occur during every stage of their life cycles during the synthesis, processing, storage or use of the final goods. The influences of the introduction of various additives on the processes of decomposition and aging of the COPE are compared. The proper choice of stabilizers and anti-oxidants, as well as initial substrates, caused the materials to endow them with excellent properties and high resistance to various environmental conditions.

    更新日期:2019-12-11
  • Physicochemical properties and in-vitro release study of CFLE-chitosan microsphere beads
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-30
    Vandana Suryavanshi, Preeti K. Suresh, Chayan Das, Tungabidya Maharana

    Chitosan is a natural heteropolysaccharide smart biodegradable polymer which is biocompatible, nontoxic, bioactive, non-immunogenic and non-carcinogenic. Chitosan has diversified biomedical applications, such as controlled drug delivery, tissue engineering and gene therapy. Encapsulation of various drug molecules as well as herbal extracts is of current interest. However, Cassia fistula plant extract, containing important agents having antioxidant, anti-inflammatory, antitussive and antifungal properties has not been encapsulated till date for its controlled release. Further, the potential of Cassia fistula and its extensive use was limited by its hydrophobicity and poor bioavailability. Hence, in the present investigation, a novel encapsulated material containing herbal extract has been developed in which Cassia fistula leaf extract (CFLE) has been encapsulated into chitosan. Thus, the present investigation is focused on the development of Cassia fistula leaf extract loaded chitosan (CFLE-CS) microsphere beads. The prepared CFLE-CS beads has been characterized by using FT-IR, NMR, TGA/DTA/DSC, XRD, SEM, and further, the drug release behavior was studied at two different pH (2.0 and 7.4), at 37 °C using UV-Visible spectroscopy.

    更新日期:2019-12-11
  • A review and future prospect of polymer blend mixed matrix membrane for CO 2 separation
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-30
    Kar Kit Wong, Zeinab Abbas Jawad

    In recent years, carbon capture technology has received much attention to limit the adverse effect caused by rising carbon dioxide (CO2) concentration in the atmosphere. Membrane technology has risen as an attractive option for carbon capture as it is less energy–intensive and more environmentally friendly compared with adsorption, absorption, and cryogenic separation. Polymeric membranes dominate the gas separation industries as they are cheaper and easier to fabricate compared with inorganic membranes but are bound to the permeance-selectivity trade-off limitation. Recently, researchers have been modifying polymeric membrane by polymer blending and mixed matrix membranes (MMMs) to overcome the limitation. Polymer blending yields a polymer blend that combines the benefits of two or more polymeric material. Polyethylene glycol (PEG) and polyethersulfone (PES) are common polymeric materials used in the gas separation industry for membrane fabrication. PEG and PES were reviewed in this paper as potential polymer blends that efficiently separate CO2 due to their chemical characteristics. Another technique to overcome the trade-off limitation is fabricating MMMs that incorporate both polymeric membrane material and inorganic filler. However, MMM fabrication presents challenges such as polymer-filler incompatibility, void formation, and filler agglomeration due to unsuitable filler. Functionalized multi-walled carbon nanotubes (MWCNTs-F) were reviewed as fillers that are able to overcome the dispersion and polymer-compatibility issues and increase the gas separation performance of membranes. Hence, MMM that is fabricated from PEG, PES, and MWCNTs-F that combines both polymer blending and MMM techniques is believed to be a breakthrough for CO2/N2 separation.

    更新日期:2019-12-11
  • Synthesis and corrosion inhibition studies of modified polyacrylic acid bearing triazole moieties on aluminium in alkaline medium
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-29
    Ranganathan Punitha, Selvaraj Dinesh Kirupha, Selvaraj Vivek, Lingam Ravikumar

    Novel modified Polyacrylic acid (ACTP) bearing triazole pendant moieties prepared with polyacrylyl chloride and 3-amino-1,2,4-triazole-5-thiol through polycondensation reaction. The synthesized polymer was characterized using nuclear magnetic resonance (lH-NMR, 13C-NMR), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive studies (EDAX) and thermogravimetric (TGA) studies. The ACTP polymer was tested as corrosion inhibitor with aluminium metal in alkaline medium and their results were compared with synthesized simple polyacrylic acid (PAA). Gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization techniques were used to test the efficiency of the corrosion inhibitor. Activation energy and free energy for inhibition reaction supports both chemical and physical adsorption mechanism, with better inhibition efficiency. Potentiodynamic polarization curves validated that the corrosion inhibitors behave an anodic type.

    更新日期:2019-12-11
  • Layer-by-layer self-assembly of polyethyleneimine and poly(4-styrene sulfonic acid-co-maleic acid) forming composite polyelectrolyte membranes for pervaporation of aqueous alcohol solutions
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-27
    Manuel Reyes De Guzman, Micah Belle Marie Yap Ang, Shu-Hsien Huang, Wan-Ru Jhuang, Hui-An Tsai, Chien-Chieh Hu, Kueir-Rarn Lee, Juin-Yih Lai

    Composite polyelectrolyte pervaporation membranes were fabricated through layer-by-layer self-assembly method. Cationic polyethyleneimine (PEI) and anionic poly(4-styrene sulfonic acid-co-maleic acid) (PSSMA) polyelectrolytes were deposited one after the other on a porous asymmetric modified polyacrylonitrile (mPAN) substrate. Attenuated total reflection–Fourier transform infrared spectral analysis and X-ray photoelectron spectrometry confirmed the deposition of polyelectrolytes on the mPAN support. Field emission scanning electron microscopy depicted that pores in the mPAN support were covered with layers of polyelectrolytes. Atomic force microscopy illustrated that the deposition of polyelectrolytes led to a smooth surface of the membrane. Moreover, the membrane exhibited improved hydrophilicity. We investigated the effect of polyelectrolyte concentrations on the efficiency of dehydrating 90 wt% aqueous alcohol solutions through pervaporation. The results established that bilayer polyelectrolyte membranes fabricated from 0.9 wt% PEI and 0.1 w% PSSMA delivered maximal dehydration efficiency.

    更新日期:2019-12-11
  • A study on development of alternative biopolymers based proton exchange membrane for microbial fuel cells and effect of blending ratio and ionic crosslinking on bioenergy generation and COD removal
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-26
    Ching-Hwa Lee, Narangarav Terbish, Shima L. Holder, Srinivasa R. Popuri, Lakshmi P. Nalluri

    The use of biopolymers as alternative proton exchange membranes (PEMs) is receiving significant attention in microbial fuel cells (MFCs) due to their attractive and competitive physico-chemical properties, eco-friendly behavior and biodegradable nature. In this study we developed the biopolymer-based blend PEMs using chitosan (Cs) alginate (Alg) for bioelectricity production and simultaneous wastewater treatment and also investigated the effect of blending ratio of the membrane and ionic crosslinking between the two biopolymers on MFC performance. The membranes of Cs:Alg were fabricated in volume ratio of 100:0, 80:20, 60:40, 50:50, 40:60, 20:80, and 0:100 via a solution casting and solvent evaporation method followed by crosslinking with phosphoric acid to avoid excess swelling of the hydrophilic polymers and increase the mechanical strength. Among these, the 50:50 ratio membranes exhibited the highest power generation (115 mW/m2) with 1340% water uptake, however the membrane with 40:60 ratio displayed maximum COD removal (78.6%) compared to other membranes. The structure and surface morphology of obtained membranes were examined using Infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX), Sorption and cation exchange capacity, and tensile strength. Sorption, cation exchange capacity and mechanical properties of Cs membranes increased with the addition of Alg with near to stoichiometric ratio.

    更新日期:2019-12-11
  • Characterizations of doxorubicin-loaded PEGylated magnetic liposomes for cancer cells therapy
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-25
    Andri Hardiansyah, Fredina Destyorini, Yuyun Irmawati, Ming-Chien Yang, Chi-Ming Liu, Elsy Rahimi Chaldun, Ming-Chi Yung, Ting Yu Liu

    Magnetic-guided drug delivery system for cancer treatment can be realized by elaborating drug and magnetic nanoparticles (MNP) on the liposomes through the assistance of magnetic field exposure. Here, we prepared PEGylated liposomes (liposomes with poly-(ethylene glycol) (PEG) modification) to encapsulate doxorubicin (DOX) and MNP, termed as DOX-loaded PEGylated magnetic liposomes. We show that the DOX-loaded PEGylated magnetic liposomes exhibits spherical morphology with diameter about 100 nm, dispersed homogeneously in aqueous system and generate inductive heating from 37o to 56 °C by means of high-frequency magnetic field (HFMF) exposure. Moreover, DOX could kill HeLa cells due to DOX releasing indicating the DOX cytotoxicity to the HeLa cells as a function of DOX concentration. In conclusion, these liposomes could combine the function of DOX and MNP, opening a route as a drug carrier platform to enhance the therapeutic efficacy of chemotherapeutic drug and it could be integrated with the development of magnetic-guided drug delivery.

    更新日期:2019-12-11
  • Temperature and deformation dependence of structural evolution in polyamide 1010
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-25
    Zhenya Zhang, Wentao Liu, Hao Liu, Jin Zheng, Aihua Sun, Yong Li, Suqin He, Chengshen Zhu, Mingcheng Yang

    Polyamide 1010 (PA1010) is a representative of long-chain polyamides, used in applications requiring good mechanical, thermal and chemical properties. It has a lower melting point and slightly higher flexible properties compared to nylon 66. Very few reports have been focused on the structures and properties of long-chain polyamides, which brings some troubles on their processing and applications. For the purpose of understanding mechanical changes within different temperature interval, dynamic structure transition of PA1010 was investigated by wide-angle X-ray diffractometer (WAXD) equipped with a hot stretching stage. During the process of the simultaneous thermal stretched, in addition to the Brill transition phenomenon, it was also accompanied by changes in crystallinity, orientation and tensile force. Both annealing and stretching can promote crystallization, in addition, stretching can also induce and destroy crystallization. With stretch ratios increasing, the crystallinity increases firstly, reaches the maximum when stretch ratio is 2.25 times and then decreases. The degree of orientation increase firstly but increase poorly after 2.50 times. The stretch force increase gradually too. The stretch force has a stronger ability than temperature to induce the PA1010 undergo the Brill transition. The presented results show that Brill transition is completed and the α-crystal structure completely transformed into γ-crystal structure when the stretch ratio is 2.50 times.

    更新日期:2019-12-11
  • Integration of phosphoric acid onto radiation grafted poly (2,3-epoxypropyl methacrylate) -PP/PE non-woven fabrics aimed copper adsorbent via response surface method
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-25
    Nor Azillah Fatimah Othman, Sarala Selambakkannu, Teo Ming Ting, Azian Hashim, Tuan Amran Tuan Abdullah

    This study focuses on preparation of new adsorbent for copper by radiation induced grafting (RIG) of 2,3-epoxypropyl methacrylate (EMPA) onto PP/PE non-woven fabric (NWF) with subsequent functionalization with phosphoric acid (PA). The density of phosphoric acid incorporated onto EMPA-g-NWF was tuned by reaction parameters optimization such as PA concentration, reaction temperature, reaction time and EMPA grafting yield by using response surface method (RSM) engaging Box-Behnken design (BBD). Maximum PA density of 2.0 mmol/g−1 was estimated at optimum reaction parameter of 45.50% PA concentration, 70 °C reaction temperature, 2.76 h reaction time and 132.68% grafting yield. The deviation between optimum experimental and projected phosphoric acid density was taken into consideration, in order to verify the consistency of RSM in predicting the yield and optimizing the functionalization reaction parameters. The PA-functionalized EMPA-g-NWF was assessed with X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, thermogravimetric (TGA), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy-energy dispersive x-ray (SEM-EDX) to examine the crystallinity, chemical composition, thermal stability and morphology, and respectively. The preliminary study on adsorption of copper was carried out with PA-functionalized EMPA-g-NWF at different conditions such as different initial copper concentration, PA density and contact time. The maximum adsorption was obtained at pH of 4. The adsorption capacity increases as the PA density increases and maximum adsorption obtained at 2.5 mmol/g-ad of PA density. The adsorption results obtained was very promising and suggested PA-functionalized EMPA-g-NWF as a suitable candidate for copper removal.

    更新日期:2019-12-11
  • Utilization of L-serinyl derivate to preparing triple stimuli-responsive hydrogels for controlled drug delivery
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-23
    Chun Hui Luo, Xin Xin Sun, Feng Wang, Ning Wei, Fa Liang Luo

    Environmentally responsive hydrogels are widely used in various applications. Facile synthesis of multiply stimuli-responsive hydrogels is necessary. Herein, a triple pH-, thermo- and ion-sensitive hydrogel, shorted as HSP, was synthesized by aqueous radical polymerization using L-serinyl acrylate as a monomer and PEG180DMA as a crosslinker. The compositions and microstructures of HSP are characterized by FT-IR, 1H NMR and SEM. The swelling ratio of HSP is the lowest at pH = 3.0 while increases sharply far away from this pH value. Meanwhile, HSP expands with elevated temperatures or ionic strengths, and reaches a plateau when they above 60 °C or 3.0 mol/L, respectively. In addition, these swelling processes are reversible under alternative changing in extern stimuli, and these cycles can be repeated at least 5 times. Furthermore, the release of sodium salicylate can be easily mediated by pH values, temperatures and ion concentrations, all above indicating that HSP is a promising material for controlled drug delivery.

    更新日期:2019-12-11
  • Polydopamine-functionalized graphene oxide compounded with polyvinyl alcohol/chitosan hydrogels on the recyclable adsorption of cu(II), Pb(II) and cd(II) from aqueous solution
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-23
    Ting Li, Xiaojin Liu, Luzhong Li, Yang Wang, Piming Ma, Mingqing Chen, Weifu Dong

    Polydopamine-Functionalized graphene oxide (PDA-GO) was used to form Polyvinyl Alcohol/Chitosan/PDA-GO (PVA/CS/PDA-GO) hydrogels. FTIR, TGA and SEM investigation showed that PDA had been successfully loaded on graphene oxide nanosheets. Adsorption of metal ions onto the novel PVA/CS/PDA-GO hydrogel beads with variations in pH, contact time, initial metal concentration and temperature had been investigated. Adsorption data were well accurately described by Langmuir isotherm and pseudo-second-order kinetic model at the optimum pH 5.5. The maximum adsorption capacities of the PVA/CS/PDA-GO were 210.94 mg·g−1, 236.20 mg·g−1 and 214.98 mg·g−1 for Cu(II), Pb(II) and Cd(II) ions with 40 C, respectively. Meanwhile, desorption efficiency and reusability of the adsorbents were assessed on basis of six consecutive adsorption-desorption cycles. This work provides a simple and environmentally friendly method to obtain the PVA/CS/PDA-GO hydrogel beads, which really would be a potential recyclable adsorbent for removal of hazardous metal ions in waste water.

    更新日期:2019-12-11
  • Reversing and non-reversing effects of PEEK-HA composites on tuning cooling rate during crystallization
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-23
    Sujoy Kumar Dey, Somenath Chatterjee, Florian Spieckermann, Pradipta Ghosh, Sutanu Samanta

    The development of bio-compatible materials for bone implants bone healing is one of the key research areas in biomaterials. In this paper, composites of polyether-ether-ketone (PEEK) (a bio-compatible polymer) and hydroxyapatite (HA) were synthesized using thermal process, The qualities of the composites were analyzed with X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) for characterizing the nature of stress and bonding. The morphological study of the PEEK-HA composites were studied through Scanning electron microscopy. The compressive nature of the composites as well as raw materials was observed based on XRD data with internal lattice-strain analysis. The temperature-modulated differential scanning calorimetry (TM-DSC) and conventional differential scanning calorimetry (DSC) were performed for analyzing the crystallization process. The TM-DSC showed that both reversing and non-reversing processes were active during the crystallization between 160 °C–330 °C. However, a higher residual time of PEEK at elevated temperatures tends to facilitate polymer degradation and spread the crystallization process over a broader temperature range. Addition of HA particles provided heterogeneous nucleation sites for crystallization but also reduced the mobility of polymer chains. The combination of enhanced nucleation rate, reduced chain mobility and polymer degradation processes together lead to a wide range of crystallinity in PEEK-HA composites.

    更新日期:2019-12-11
  • Effect of chemical structure of hydrazide compounds on nucleation effect in isotactic polypropylene
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-21
    Yue-Fei Zhang, Jing-Jing Mao

    A series of hydrazide compounds were synthesized and employed as nucleating agents for isotactic polypropylene (iPP). The effect of different structures of hydrazide compounds on the crystallization and melting behaviour of iPP was studied by differential scanning calorimetry (DSC). The results demonstrate that almost all nucleating agents are α-nucleating agents, some of which are highly efficient nucleating agents. In the case of the same substituent, the greater the number of hydrazide groups, the better the nucleation effect. The crystallization peak temperature (Tc) of iPP nucleated with dihydrazide is 3–4 °C higher than that of monohydrazide. When the substituent of the dihydrazide compound is hydrogen, ethyl and nonyl, their nucleating ability is relatively weak, but in the state of phenyl and cyclohexyl substitution, the Tc of iPP nucleated with dihydrazide nucleating agent is 8.5 °C than pure iPP. When the intermediate group of the dihydrazide compound is a long-chain alkyl, a phenyl, a cyclohexyl, and a naphthyl group, the phenyl group and the cyclohexyl group still exhibit an excellent effect, the Tc of nucleated iPP is raised by about 10 °C.

    更新日期:2019-12-11
  • pH-responsive hydrogels based on the self-assembly of short polypeptides for controlled release of peptide and protein drugs
    J. Polym. Res. (IF 1.53) Pub Date : 2019-11-21
    Xue Bao, Xinghui Si, Xiaoya Ding, Lijie Duan, Chunsheng Xiao

    In this study, a pH-responsive hydrogel consisting of a 4-arm poly(ethylene glycol)-block-poly(L-glutamic acid) (4a-PEG-PLG) copolymer was developed and used for the controlled release of peptide and protein drugs. It was found that the mechanical properties and degradation processes of the hydrogels could be tuned by changing the polymer concentrations. In vitro drug release results revealed that the release of insulin (or BSA) from hydrogel was highly dependent on the pH, i.e., less than 20% of insulin (or BSA) was released in the artificial gastric fluid (AGF) at 72 h, while close to 100% of insulin (or BSA) was released in the artificial intestinal fluid (AIF). It was because that the deprotonation of carboxyl groups in PLG block caused the disassembly, and even disintegration of the hydrogel in AGF, thereby resulting in accelerated drug release. Circular dichroism spectra showed that the bioactivities of insulin and BSA released from hydrogels were obviously unchanged compared to those of native insulin and BSA, respectively. Mouse fibroblast L929 cells were cultured on the surface of hydrogels and the viabilities of cultured cells were above 90% after incubation for 24 h, indicating that the hydrogels had good cytocompatibilities. Moreover, in vivo degradation evaluation disclosed that the formed hydrogels will completely degrade after 8 days, and the H&E staining study demonstrated the excellent biocompatibility of the as-prepared hydrogels. Therefore, the biocompatible and biodegradable 4a-PEG-PLG hydrogel may serve as a promising platform for pH-responsive drug delivery.

    更新日期:2019-12-11
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