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Polyphosphonate-Based Macromolecular RAFT-CTA Enables the Synthesis of Well-Defined Block Copolymers Using Vinyl Monomers
ACS Macro Letters ( IF 5.1 ) Pub Date : 2021-10-04 , DOI: 10.1021/acsmacrolett.1c00564
Diego A Resendiz-Lara 1 , Frederik R Wurm 1
Affiliation  

Reversible addition–fragmentation chain transfer (RAFT) polymerization has become a straightforward approach to block copolymers using a wide variety of functional vinyl monomers. Polyphosphoester (PPE) macroinitiators from ring-opening polymerization (ROP) of their corresponding cyclic phosphoesters have been previously prepared for atom transfer radical polymerization; however, to date, these biodegradable macroinitiators for RAFT polymerization have not been reported. Herein, a macromolecular RAFT-chain transfer agent (CTA) based on poly(ethyl ethylene phosphonate) was prepared by the organocatalytic ROP of 2-ethyl-2-oxo-1,3,2-dioxaphospholane using 2-cyano-5-hydroxypentan-2-yl dodecyl trithiocarbonate as the initiator and 1,8-diazabycyclo[5.4.0]undec-7-ene as the catalyst. Precise macro-CTAs of degrees of polymerization (DPn) from 34 to 70 with Đ ≤ 1.10 were prepared and used in the dioxane solution RAFT polymerization of acrylamide, acrylates, methacrylates, and 2-vinylpyridine to yield a library of well-defined block copolymers. Additionally, the PPE-based macro RAFT-CTA was used as a nonionic surfactant in a typical aqueous emulsion polymerization of styrene to produce well-defined nanoparticles with the hydrophilic PPEs on their surface as the stabilizing agent. This general protocol allowed the combination of polyphosphoesters with RAFT polymerization.

中文翻译:

基于聚膦酸酯的大分子 RAFT-CTA 能够使用乙烯基单体合成定义明确的嵌段共聚物

可逆加成-断裂链转移 (RAFT) 聚合已成为使用多种官能乙烯基单体制备嵌段共聚物的直接方法。来自其相应环状磷酸酯的开环聚合 (ROP) 的聚磷酸酯 (PPE) 大分子引发剂已预先制备用于原子转移自由基聚合;然而,迄今为止,这些用于 RAFT 聚合的可生物降解大分子引发剂尚未见报道。在此,以 2-氰基-5-羟基戊烷为原料,通过 2-乙基-2-氧代-1,3,2-二氧杂膦的有机催化 ROP 制备了基于聚(乙基膦酸乙酯)的大分子 RAFT 链转移剂(CTA)。 -2-基十二烷基三硫代碳酸酯作为引发剂,1,8-二氮杂环[5.4.0]undec-7-ene作为催化剂。聚合度的精确宏观 CTA (DPn ) 从 34 到 70 且Đ ≤ 1.10 被制备并用于丙烯酰胺、丙烯酸酯、甲基丙烯酸酯和 2-乙烯基吡啶的二恶烷溶液 RAFT 聚合,以产生定义明确的嵌段共聚物库。此外,基于 PPE 的大分子 RAFT-CTA 在典型的苯乙烯水乳液聚合中用作非离子表面活性剂,以生产定义明确的纳米颗粒,其表面具有亲水性 PPE 作为稳定剂。该通用协议允许将多磷酸酯与 RAFT 聚合结合。
更新日期:2021-10-19
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