Proton Transfer Anionic Polymerization of Methyl Methacrylate with Ligands for Dual Control of Molecular Weight and Tacticity

Precision Chemistry Pub Date : 2024-10-15 DOI:10.1021/prechem.4c0006610.1021/prechem.4c00066

Katsutoshi Sagawa, Mineto Uchiyama*, Hironobu Watanabe, Chihiro Homma and Masami Kamigaito*,

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Abstract

Dual control of the molecular weight and tacticity in proton transfer anionic polymerization (PTAP) of methyl methacrylate (MMA) was investigated by using various ligands in the presence of a bulky potassium base catalyst and an organic compound with a weakly acidic C–H bond as dormant species in toluene at 0 °C. The tacticity of the resulting poly(MMA) (PMMA) produced without ligands was nearly atactic (rr/mr/mm = 22/54/24). However, the use of 18-crown-6 as a ligand afforded predominantly syndiotactic PMMA (rr ≈ 58%), whereas the use of chiral bis(oxazoline) ligands gave slightly isotactic-rich PMMA (mm ≈ 32%). Molecular weight control of PMMA was achieved (Đ = 1.1–1.2) by adding 1,1-diphenylethanol as a reversible terminator while maintaining control of the tacticity with the above ligands. Stereoblock PMMA consisting of atactic and syndiotactic segments was successfully synthesized via sequential PTAP using macroinitiator/macro-CTA methods.

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甲基丙烯酸甲酯与配体的质子转移阴离子聚合及其对分子量和弹性的双重控制

本文研究了甲基丙烯酸甲酯（MMA）质子转移阴离子聚合（PTAP）过程中，在0℃甲苯中，以大体积钾碱催化剂和具有弱酸性C - h键的有机化合物为休眠物的情况下，采用不同配体对分子量和弹性的双重控制。无配体制备的聚（MMA）（PMMA）的弹性几乎为零（rr/mr/mm = 22/54/24）。然而，使用18-冠-6作为配体可获得主要的顺规PMMA (rr≈58%)，而使用手性双（恶唑啉）配体可获得稍富等规的PMMA （mm≈32%）。通过加入1,1-二苯乙醇作为可逆终止剂，在保持与上述配体的亲和性控制的同时，实现了PMMA的分子量控制（Đ = 1.1-1.2）。采用macroinitiator/macro-CTA方法，通过序贯PTAP成功合成了由无规段和共规段组成的立体嵌段PMMA。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Precision Chemistry 精密化学技术-

CiteScore

0.80

自引率

0.00%

发文量

期刊介绍： Chemical research focused on precision enables more controllable predictable and accurate outcomes which in turn drive innovation in measurement science sustainable materials information materials personalized medicines energy environmental science and countless other fields requiring chemical insights.Precision Chemistry provides a unique and highly focused publishing venue for fundamental applied and interdisciplinary research aiming to achieve precision calculation design synthesis manipulation measurement and manufacturing. It is committed to bringing together researchers from across the chemical sciences and the related scientific areas to showcase original research and critical reviews of exceptional quality significance and interest to the broad chemistry and scientific community.