Lubrication is one of the most important parameters in unplasticized polyvinyl chloride (uPVC) processing apart from the PVC resin and processing equipment. Lubricants are used in specific ratios to ensure effective fusion of PVC particles. The exact mechanism on how these lubricants interact is not yet fully understood. A widely accepted theory is the interaction mechanism proposed by Rabinovic et

An experimental and semi-analytical study of distortion of asymmetric composite laminates with different cooling rates and lay-ups has been presented. In this study, thermomechanical constitutive equations of thin composite laminates are developed using basic viscoelastic constitutive law considering chemical and thermal effects with time-temperature dependent material properties. To solve a fully

This work provides a direct comparison of several experimental approaches used in the literature to measure fracture toughness of rubber of rubber using single edge notched in tension (SENT) specimens, with the final aim to provide guidelines for an optimal testing procedure. Digital image correlation measurements were used to get new insights into the fracture process. SENT is experimentally advantageous

Accurate and concise constitutive model of biaxial tensile behavior is urgently needed for the analysis of complex membrane structure engineering. A new constitutive model is developed to describe the tensile behaviors of coated fabrics from pre-tension to breaking. The shrinkage curves is employed for the first time and stress-ratio dependence coefficient (SDC) is proposed to represent the proportion

Driven by the market demand, several synthetic and natural grafts have been proposed during the last years for tendons regeneration. The synthetic grafts, which present a better mechanical performance than the natural ones, usually fail due to the lack of biocompatibility and bioactivity. Thus, chitosan (Cs) was immobilized on polypropylene (PP) surface, previously activated by plasma treatment, in

BaTiO3/bismaleimide/epoxy/glass fiber reinforced composites were prepared using E-glass fiber (E-GF) and silane coated E-glass fiber (SC-EGF) separately as reinforcement. BaTiO3 nanoparticles were prepared by hydrothermal method. Results show that the addition of BaTiO3 nanoparticles has significant effects on the mechanical and dielectric properties of the composite. Both E-GF and SC-EGF reinforced

Whereas size reduction that accompanies new technologies calls for more complex and more constrained shapes for foams to be used as seals, ribbons or surface coatings, little is known about the mechanics of foam systems characterized by a potentially small number of pores across their thickness and possessing parietal or free surface pore layers. Elastic stiffness and rupture stress have been measured

The pyrolysis behaviors of l-tyrosine-based phthalonitrile(TPN) resin were investigated by thermogravimetric-Fourier transform infrared spectrometry-mass spectrometry (TG-FTIR-MS) and Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The small molecules produced during pyrolysis process of TPN resin were tracked in real time by TG-FTIR-MS. The larger molecules (m/z > 40) from fast pyrolysis

The resiliency of advanced laminated nanocomposite materials to mitigate impact load is an essential characteristic for material selection and product design. This paper investigates the effect of nanofillers and its effect on the damage resistance performance of a newly developed woven Kevlar fabric. Three types of nanofillers were investigated: (1) Silicon carbide (SiC), (2) aluminum oxide (Al2O3)

In this study, we investigate the effect of M-Type zirconium doped barium hexaferrite nanoparticles addition with reduced graphene oxide (RGO) fillers in Polyvinylidenefluoride (PVDF) matrix to design lightweight and flexible polymer composite films for electromagnetic wave absorption and electromagnetic interference (EMI) shielding. Firstly, Zr doped M-Type barium hexaferrite (BaZrFe11O19) nanoparticles

This paper presents the influence of Aluminum Nitride (AlN) nanoparticles on the electrical and material properties of epoxy resin (EP). The EP/AlN nanocomposites with different concentrations of nano-AlN fillers are prepared. The dispersion of the nano-AlN particles in the composites is analyzed by a field emission scanning electron microscope (FESEM). The electrical properties are investigated by

In this paper, steady-state luminescence spectroscopy is used for the analysis of curing of epoxy resin. The advantage of this method is its rapidity, simplicity and sensitivity. Moreover, this method is contactless, and thus non-invasive. The aim is to analyze epoxy resin, mathematically describe its curing kinetics and determine its storage temperature. Using the photoluminescence method, a rapid

Flame retardants (FRs) are applied to select consumer products such as baby clothing, construction materials, electronics and furniture upholstery to slow or prevent fire ignition or growth by physical/chemical mechanisms. The most commonly used FRs have historically been halogenated molecules. However, their bioaccumulation in mammals has been investigated, leading to some of them to be banned. As

A combination of solution casting and melt extrusion technique was used to fabricate Boron nitride (BN)-filled Polylactic acid (PLA)/polybutylene adipate terephthalate (PBAT) blend composites. The BN particles were surface treated with a silane coupling agent and functionalization was confirmed via spectroscopic analysis. Field emission scanning electron microscopy confirmed that the BN surface treatment

FTIR-ATR (Focal Plane Array) FPA spectroscopic imaging was used to obtain depth resolved information about degradation of a polyester melamine coating by performing measurements on drilled conical holes. The results of the FTIR-FPA imaging show that combined effect of UV and moisture resulted in larger degradation effects in the outermost parts of the coatings but loss of melamine functionality was

Dynamic Mechanical Analysis (DMA) systems are measurement devices for obtaining master curves and complex modules of viscoelastic materials, such as rubbers. The conventional DMAs measurement systems in market have several limitations, which restrict their ability for operating at high frequencies. Thus, Williams, Landel and Ferry (WLF) relation is used to produce master curves and predict the material

In this study, slow crack growth (SCG) resistances of defective and normal high density polyethylene (HDPE) pipes were measured using the stiff-constant K (SCK) specimen, where the stress intensity factor (SIF) was maintained at a constant value within a certain crack length range. A significantly reduced SCG resistance was observed in the defective pipe; a detailed procedure for evaluating SCG kinetics

In this study, experimental tests and a statistical analysis are conducted to verify the size effects associated with length on the tensile behavior of dry unidirectional carbon fiber sheets (DUCFS). As a statistical method, the two-parameters Weibull theory is considered. To verify the validity of the Weibull theory, four sets of direct tensile test were made on DUCFS specimens having different lengths

Carbon Nanotubes (CNTs) is among the most promising nanofiller materials that could be used for enhancing the properties of fiberglass/epoxy laminates for vehicle industries with less CO2 emission (the key player in the climate change). However, usually the commercialized CNTs are supplied in the shape of heavily entangled tubes what leads to random dispersion of CNTs in the polymer matrix and decrease

A thin layer of un-cured resin over metal substrates applied by using an acetone-diluted resin solution (without hardener) has been found to be beneficial to strong adhesive bonding. The resin pre-coating (RPC) solution can effectively seal sub-surface micro-cavities and increase the substrate wettability. This study examines possible aftermath effects of the acetone dilution on mechanical properties

Balancing antibacterial properties with biocompatibility is of paramount importance for wound dressings loaded with antibacterial agents. In this work, a water soluble antibacterial agent, quaternized chitosan (hydroxypropyltrimethyl ammonium chloride chitosan, HACC) with an appropriate degree of substitution was introduced into the bacterial cellulose (BC) network by adding it into the BC culture

Nitrocellulose (NC)-based propellants require stabilizers to avoid early decomposition or even explosion during storage. A series of novel fullerene-malonamide derivatives with different carbon chain lengths on the p-position of the benzene ring was synthesized as stabilizers for NC-based propellants through the Bingel reaction because of the excellent thermal stability and strong ability of these

The consumption of the polymeric membrane is increased over the years due to the high demand from the industries. This work attempts to evaluate the performance of polyethersulfone (PES) membrane incorporated with cellulose nanofibrils (CNF), which can be extracted from empty fruit bunches generated from palm oil mills. PES/CNF/polyvinylpyrrolidone (PVP) blend membranes were fabricated using phase

To persuade the stent coating materials for the better sustainable development, a block copolymer composed of hydrophobicity of poly(trimethylene carbonate) (PTMC) and hydrophilicity of PTMC bearing ethylene glycol chains was synthesized as a potential candidate. The result of thermal stability of the polymer was analyzed which reached up to 206 °C (T10) and it is considered that sufficient for sterilization

Polyurea, a reaction product of isocyanates and an amine blend has been reported to be highly strain rate sensitive, which responds in its own unique way when subjected to increasing strain rates. The amine blend comprise of a long chain amine, forming the soft segments, chain extender, which brings the urea linkages closer and a crosslinker, which serves as a chemical bond between the chains. In this

To claim ‘wearability’, clothing for protection against impact injury must not only act locally as a rigid shell under impact in order to satisfy drop-weight tests, but also flex freely with normal movement and offer permeability and light weight. Previous materials used carrier textiles coated with ‘dilatant’ but mechanically weak polyborodimethylsiloxane (PBDMS) compounds. We outline a procedure

Fused deposition modeling (FDM) is an important process among the available additive manufacturing technologies in various industries. Although there exists many works investigating the effects of FDM process parameters on the mechanical properties of printed materials, there are still several points need to be studied. One is the effects of process parameters on the dynamic mechanical properties of

Silicone polymers have enormous applications, especially in the areas of biomedical engineering. Ecoflex, a commercially available room temperature cured silicone polymer, has attracted considerable attention due to its wide range of applications as medical-grade silicones and as matrix materials in producing nano-filled stretchable sensors and dielectric elastomers for soft robotics. In this contribution

Polysiloxane-based polyurethane films with cross-linked structure are synthesized by the sol-gel process using isophorone diisocyanate (IPDI), polydimethylsiloxane (PDMS), polycaprolactone (PCL) diol, and 3-aminopropyl triethoxysilane (ATS). After the ATS-terminated polyurethane prepolymer, a cross-linked network structure is formed through the process of dehydration and condensation. The hydrophobicity

The effect of polylactic acid (PLA), cellulose microfibers (CEL), and calcium carbonate (CaCO3) on the equilibrium moisture content (EMC), density and flexural mechanical properties of starch-based bio-foams was studied using a full factorial design 23. Also, a moisture aging study was carried out. The results show the three factors studied changed the bio-foams morphology, contribute to density increment

Adding high loadings of nanoparticles can remarkably alter the functionality of polymer nanocomposite foams. Therefore, this dramatic change was studied at the percolation threshold as a point to predict the properties of foamed nanocomposites using the viscoelastic characteristics of un-foamed ones. In this research, the effect of incorporating 10–40 wt% of ZnO nanoparticles on rheological properties

A critical failure mechanism in long-term applications of plastic structures, such as piping systems, is considered to be crack initiation and subsequent Slow Crack Growth (SCG). Thus, safe installation and operation during service lifetime of such structures are not conceivable without the knowledge of the resistance against SCG for any new material, like unplasticized polyamide 12 (PA-U12). Unfortunately

This paper aims to investigate the mechanical behaviors of carbon fiber-reinforced PEEK-Titanium hybrid laminates (TiGr) prepared by different surface treatment conditions using silane coupling agent. In order to improve the bonding performance between the titanium sheets and PEEK, the titanium layers were subjected to sandblasting roughening and silanization treatment, the curing process was explored

It is elementary to recognize the benefits and the negative impacts of the use of plastic materials on modern societies. Polyethylene (PE) is the major plastic component present in the municipal solid waste. In this paper, two types of low-density PE (LDPE) waste with different mechanical recycling stress histories were used to investigate the influence of recycling cycles on pyrolysis. The kinetic

The crystallization behavior of polymers is usually investigated by the Differential Scanning Calorimetry (DSC) under isothermal or non-isothermal conditions, the latter one at constant cooling rates. The results of such experiments are used to calculate the crystallization during the dynamic cooling of processing, for instance with the Nakamura crystallization model. In contrast, in this article the

Rubber is a type of material widely used in industries for waterproofing, storing and transporting fluids, energy shock dampers, thermal insulation, and corrosion protection. Natural Rubber (NR) polymer is a material that is extensively used in the automotive industries because of its unique properties such as high strength, low weight, and excellent corrosion resistance. In this study, the mechanical

The viscoelastic behavior of multiwall carbon nanotube (MWCNT) reinforced polyamide 66 (PA 66) was evaluated to investigate the effect of CNT content and loading frequency on dynamic moduli (i.e. storage modulus E’ and loss modulus E”) and damping factor tanδ. PA 66/CNT disk samples with five different CNT contents ranging from 3 wt % to 15 wt % were manufactured by injection molding. Testing was performed

The mechanical strength of polymer scaffold is closely related to its crystallinity. In this work, cellulose nanocrystals (CNC) were incorporated into poly-l-lactide (PLLA) scaffold which was fabricated by selective laser sintering, aiming to improve the mechanical properties. CNC possesses numerous hydroxyl groups which might form hydrogen bond with PLLA molecular chains. The hydrogen bond induces

A spectrophotometric method was developed for the selective estimation of titanium in alkoxide form in the presence of TiO2. Polymers like polybutylene terephthalate have been synthesized by using homogeneous catalyst such as titanium tetra-isopropoxide (TTIP). These types of catalysts are susceptible to moisture and convert to inactive TiO2. Hence, it is essential to have analytical method for selective

The effect of initial fiber orientation and welding conditions on the mechanical properties and microstructure of 30 wt% glass-fiber-reinforced polyamide 66 was systematically evaluated. For all conditions studied no significant change in the polymer matrix was evidenced. However, fibers in the welded zone were reoriented toward the squeeze and vibration flows and this reorientation is related to the

The glass fiber epoxy composites containing MWCNTs and Fe3O4 NPs were manufactured by composites liquid molding process. The microwave absorbing properties of single-layered and double-layered glass fiber/MWCNTs/epoxy and glass fiber/Fe3O4 NPs/epoxy composites were evaluated. The reflection loss(RL) were calculated by the measured complex permittivity and permeability using waveguide method by vector

Poly(ethylene terephthalate) (PET) has been mixed with fluorite (CaF2) particles to obtain micro- and nano-composites aiming to obtain an hybrid multifilament. In first term, the use of two montanic waxes and an amide wax as dispersing agents towards the compabilization of the inorganic and organic components of the CaF2/PET composite were considered. To do this, non-isothermal crystallization studies

Microfibrillar composites (MFC) with in-situ generated short polymeric fibres feature, unlike composites containing inorganic rigid fibres/particles, lower creep resistance in comparison with analogous blends containing spheres. Further attribute is unprecedented decrease in creep resistance of the blend by graphite nanoplatelets (GNP). Explanation of this behaviour of the HDPE/PA66/GNP system consists

This research is focused to fundamentally understand the benefits of using Agave Americana C. plant as potential reinforcement in polymeric composites. The fibers were extracted from the external part of the bark of the plant, which grows worldwide in pastures, grasslands, open woodlands, coastal and riparian zones. In order to use the natural fiber as reinforcement it is paramount important to probe

Additive manufacturing is gaining a remarkable importance in manufacturing industries because of the ability to build parts with complex and intricate shapes. The most widely used material in additive manufacturing is the polymer. In this paper, circular textures have been 3D printed on the surface of Polylactic Acid (PLA) polymer using fused deposition modelling technique. Experiments were performed

Glass fibre reinforcements form the backbone of a composites industry. Possibly the most critical component involved in the manufacture of glass fibres and their composites is the fibre sizing. Yet because of the intense level of secrecy surrounding size formulations there are few who have more than a superficial understanding of sizings. Composite developers and researchers have a growing need for

Dynamic mechanical analysis is a technique used to determine the viscoelastic properties of polymers and their composites. The storage modulus, loss modulus and loss factor in correlation with the glass transition temperature can be detected by several means. In this study, these properties are determined using a dynamic mechanical analyzer in 3-point bending mode, as well as a rheometer in torsion