当前位置: X-MOL 学术Macromol. Chem. Phys. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Controlled Synthesis of “Reverse Pluronic”‐Type Block Copolyethers with High Molar Masses for the Preparation of Hydrogels with Improved Mechanical Properties
Macromolecular Chemistry and Physics ( IF 2.5 ) Pub Date : 2020-01-09 , DOI: 10.1002/macp.201900437
Felix Markus 1 , Johanna R. Bruckner 2 , Stefan Naumann 1
Affiliation  

Hydrogels based on Pluronics (EOn/2‐POm‐EOn/2, EO = ethylene oxide, PO = propylene oxide) have been frequently investigated, yet key limitations still remain, including a propensity for quick erosion and insufficient mechanical robustness. This issue can be alleviated by creating “reverse Pluronics” (POn/2‐EOm‐POn/2), which is proposed to enable the formation of physical cross‐links via a micellar network. Until recently, however, efforts in this direction were aggravated by synthetic difficulties, specifically prohibiting the realization of poly(propylene oxide) (PPO)‐moieties with a high DP. In this study, an organocatalytic polymerization method is employed to synthesize “reverse Pluronics,” resulting in highly defined polymers (ÐM ≤ 1.02–1.07, Mn up to 35 000 g mol−1) with exceptionally long PPO blocks. The higher molar mass and the reverse constitution of the polyether combine to enable the generation of thermoresponsive hydrogels with a storage modulus that is increased tenfold relative to reference samples. Gelation temperature and maximum storage modulus (Gmax) are readily influenced by the choice of the polyether (down to 5 wt%). The improved mechanical properties are accompanied by an increased resistance toward erosion in water. Isotactic enrichment is presented as an additional tuning parameter for hydrogel properties.

中文翻译:

摩尔质量较高的“逆向多元流体”型嵌段共聚醚的控制合成,用于制备具有改善的机械性能的水凝胶

基于水凝胶的Pluronics(EO n / 2个-PO-EO N / 2,EO =环氧乙烷,PO =环氧丙烷)经常被研究,但关键的限制仍然存在,包括用于快速侵蚀和机械强度不足的倾向。可以通过创建“反向Pluronics”(PO n / 2 -EO m- PO n / 2),旨在通过胶束网络形成物理交联。然而,直到最近,由于合成困难,特别是禁止实现具有高DP的聚环氧丙烷(PPO)部分,加剧了在该方向上的努力。在这项研究中,使用的有机催化的聚合方法来合成“逆向普朗尼克”,导致高度限定的聚合物(d中号≤1.02-1.07,中号Ñ高达35000克摩尔-1)和超长的PPO块。较高的摩尔质量和聚醚的相反组成相结合,使得能够产生具有相对于参考样品增加十倍的储能模量的热响应性水凝胶。凝胶化温度和最大储能模量(G ^ '最大值)容易由聚醚的选择的影响(下降到5重量%)。改善的机械性能伴随着增加的抗水侵蚀性。等规富集作为水凝胶特性的附加调节参数。
更新日期:2020-01-09
down
wechat
bug