Janus polymerization: a one-shot approach towards amphiphilic multiblock poly(ester-acetal)s directly from 1,3-dioxolane with ε-caprolactone
Janus polymerization: a one-shot approach towards amphiphilic multiblock poly(ester-acetal)s directly from 1,3-dioxolane with ε-caprolactone
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Janus聚合：直接从1,3-二氧戊环与ε-己内酯制备两亲性多嵌段聚（酯-缩醛）的一次性方法
DOI：
10.1002/cjoc.202100782
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发表时间：
2022
影响因子：
5.4
通讯作者：
Ling Jun
中科院分区：
文献类型：
--
作者：
Qiu Huan;Shen Ting;Yang Zhening;Wu Feng;Li Xiaohong;Tu Yingfeng;Ling Jun
Janus聚合包括在单个增长聚合物链的两端的阴离子和阳离子开环聚合（AROP和CROP），随后在一个步骤中自触发扩链生成多嵌段共聚物（MBCP）。本文采用Tm（OTf）_3或Er（OTf）_3催化剂与环氧引发剂的Janus聚合反应，合成了由配位AROP和聚（1，3-二氧戊环-co-ε-己内酯）（P（DO-co-CL））嵌段的半结晶聚（ε-己内酯）（PCL）嵌段的MBCP。同时，以其它稀土三氟甲磺酸盐[RE（OTf）3，RE = Y，Nd，Gd和Lu]为催化剂或在无引发剂存在下，通过CROP合成了无规共聚物[P（DO-r-CL）]。考虑到Janus MBCPs和阳离子无规共聚物之间可区分的化学结构和热性质，Janus特征被确认为包括在单个增长链处的CROP和AROP。所得的两亲性共聚物在水溶液中自组装成具有可设计直径的纳米颗粒，其具有相应的亲水和疏水链段的比例。MBCPs具有良好的形状记忆性能，其形变温度接近人体温度，在生物医用器件中具有良好的应用前景。
Janus polymerization consists of anionic and cationic ring opening polymerizations (AROP and CROP) at the two ends of a single propagating polymer chain, followed by a self-triggered chain extension generating multiblock copolymers (MBCPs) in one step. In the contribution, Janus polymerization by Tm(OTf)_3 or Er(OTf)_3 catalyst with an epoxy initiator is applied to synthesize MBCPs of semi-crystalline poly(ε-caprolactone) (PCL) blocks from coordinated AROP and poly(1,3-dioxolane-co-ε-caprolactone) (P(DO-co-CL)) blocks from CROP of DO with CL. Meanwhile, amorphous random copolymers [P(DO-r-CL)] are synthesized as control by employing other rare earth triflates [RE(OTf)3, RE = Y, Nd, Gd and Lu] as catalysts or in the absence of an initiator via CROP. On account of the distinguishable chemical structures and thermal properties between Janus MBCPs and cationic random copolymers, Janus features are confirmed including the CROP and AROP at a single propagating chain. The resultant amphiphilic copolymers self-assemble to nanoparticles in aqueous solution with designable diameters with the corresponding ratios of hydrophilic and hydrophobic segments. MBCPs exhibit good shape memory properties with appropriate deformation temperature close to human body's, providing a prospect on the applications in biomedical devices.