Construction of nanostructures in aqueous solution from amphiphilic glucose‐derived polycarbonates

Carbohydrates are the fundamental building blocks of many natural polymers, their wide bioavailability, high chemical functionality, and stereochemical diversity make them attractive starting materials for the development of new synthetic polymers. In this work, one such carbohydrate, d‐glucopyranoside, was utilized to produce a hydrophobic five‐membered cyclic carbonate monomer to afford sugar‐based amphiphilic copolymers and block copolymers via organocatalyzed ring‐opening polymerizations with 4‐methylbenzyl alcohol and methoxy poly(ethylene glycol) as initiator and macroinitiator, respectively. To modulate the amphiphilicities of these polymers acidic benzylidene cleavage reactions were performed to deprotect the sugar repeat units and present hydrophilic hydroxyl side chain groups. Assembly of the polymers under aqueous conditions revealed interesting morphological differences, based on the polymer molar mass and repeat unit composition. The initial polymers, prior to the removal of the benzylidenes, underwent a morphological change from micelles to vesicles as the sugar block length was increased, causing a decrease in the hydrophilic–hydrophobic ratio. Deprotection of the sugar block increased the hydrophilicity and gave micellar morphologies. This tunable polymeric platform holds promise for the production of advanced materials for implementation in a diverse range of applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 432–440

碳水化合物是许多天然聚合物的基本构建单元，它们广泛的生物可利用性、高化学官能度以及立体化学多样性使其成为开发新型合成聚合物的有吸引力的起始原料。在这项工作中，一种这样的碳水化合物，即D - 吡喃葡萄糖苷，被用于制备一种疏水性的五元环状碳酸酯单体，以便分别以4 - 甲基苄醇和甲氧基聚（乙二醇）作为引发剂和大分子引发剂，通过有机催化的开环聚合反应来制备基于糖的两亲性共聚物和嵌段共聚物。为了调节这些聚合物的两亲性，进行了酸性亚苄基裂解反应以对糖重复单元进行脱保护并呈现出亲水性羟基侧链基团。在水性条件下聚合物的组装显示出有趣的形态差异，这基于聚合物的摩尔质量和重复单元组成。在去除亚苄基之前，初始聚合物随着糖嵌段长度的增加经历了从胶束到囊泡的形态变化，导致亲水 - 疏水比例降低。对糖嵌段进行脱保护增加了亲水性并产生了胶束形态。这个可调节的聚合物平台有望用于生产先进材料，以应用于各种各样的用途。© 2018威利期刊公司。《聚合物科学杂志，A部分：聚合物化学》2019年，57卷，432 - 440页