Abstract

Phosphazene base, t-BuP₂, was employed to catalyze the proton transfer polymerization (PTP) of 2-hydroxyethyl acrylate (HEA), and PTP was further combined with ring-opening polymerization (ROP) to exploit a new type of hybrid copolymerization. The studies on homopolymerization showed that t-BuP₂ was a particularly efficient catalyst for the polymerization of HEA at room temperature, giving an excellent monomer conversion. Throughout the polymerization, transesterification reactions were unavoidable, which increased the randomness in the structures of the resulting polymers. The studies on copolymerization showed that t-BuP₂ could simultaneously catalyze the hybrid copolymerization via the combination of PTP and ROP at 25 °C. During copolymerization, HEA not only provided hydroxyl groups to initiate the ROP of ε-caprolactone (CL) but also participated in the polymerization as a monomer for PTP. The copolymer composition was approximately equal to the feed ratio, demonstrating the possibility to adjust the polymeric structure by simply changing the monomer feed ratio. This copolymerization reaction provides a simple method for synthesizing degradable functional copolymers from commercially available materials. Hence, it is important not only in polymer chemistry but also in environmental and biomedical engineering.

中文翻译：

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质子转移和开环聚合相结合的混合共聚

摘要

磷腈t- BuP ₂被用于催化丙烯酸2-羟乙酯（HEA）的质子转移聚合（PTP），并将PTP与开环聚合（ROP）进一步结合以开发一种新型的杂化共聚。均聚研究表明，t -BuP ₂是室温下HEA聚合的特别有效的催化剂，具有出色的单体转化率。在整个聚合过程中，酯交换反应是不可避免的，这增加了所得聚合物结构的无规性。共聚研究表明，t- BuP ₂可以同时催化杂化共聚。通过在25°C下结合PTP和ROP。在共聚过程中，HEA不仅提供了羟基以引发ε-己内酯（CL）的ROP，而且还作为PTP的单体参与了聚合反应。共聚物的组成大约等于进料比，证明了通过简单地改变单体进料比来调节聚合物结构的可能性。该共聚反应提供了一种由市售材料合成可降解的功能共聚物的简单方法。因此，它不仅在聚合物化学中而且在环境和生物医学工程中都很重要。