All-aqueous continuous-flow RAFT dispersion polymerisation for efficient preparation of diblock copolymer spheres, worms and vesicles
All-aqueous continuous-flow RAFT dispersion polymerisation for efficient preparation of diblock copolymer spheres, worms and vesicles
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DOI：
10.1039/c8re00211h
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发表时间：
2019-05-01
影响因子：
3.9
通讯作者：
Warren, Nicholas J.
中科院分区：
文献类型：
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作者：
Parkinson, Sam;Hondow, Nicole S.;Warren, Nicholas J.
我们报道了在低成本连续流动CF反应器中通过可逆加成-断裂链转移RAFT水分散体聚合可规模化的全水合成聚（二甲基丙烯酰胺）-聚（双丙酮丙烯酰胺）PDMAm-PDAAm二嵌段共聚物球、蠕虫和囊泡。使用5 mL反应器盘管的瞬态动力学分析方法表明比等效间歇反应快得多的速率。随后通过采用20 mL盘管反应器以98%转化率合成135 g，30%/w批次的PDMAm 113大分子链转移剂macro-CTA来证明更高的通量。其不经进一步纯化用于在CF反应器中聚合DAAm。在该聚合过程中，链经历聚合诱导的自组装（比萨），产生嵌段共聚物球。该反应也比分批进行得更快，并且高分辨率动力学使得能够清楚地观察到速率提高，这是比萨系统的特征。GPC研究表明，尽管在前体大分子CTA合成期间实现了高转化率，但形成了具有低摩尔质量分散度和完全封闭效率的共聚物。随后证明，PDMAm 113大分子CTA可用于制备具有系统增加的粒径的PDMAm 113-PDAAmx嵌段共聚物球，其中x = 50、100和200。最后，通过将PDMAm macro-CTA DP降低至50并将总固体增加至20% /w，可以通过调整停留时间来在管式反应器中制备蠕虫和囊泡，以实现PDAAm嵌段的特定聚合度。
We report the scalable, all-aqueous synthesis of poly.dimethylacrylamide)-poly.diacetone acrylamide) PDMAm-PDAAm) diblock copolymer spheres, worms and vesicles by reversible addition-fragmentation chain transfer RAFT) aqueous dispersion polymerisation in a low-cost continuous-flow CF) reactor. A transient state kinetic profiling method using a 5 mL reactor coil indicated a considerably faster rate than the equivalent batch reaction. Higher throughput was subsequently demonstrated by employing a 20 mL coil reactor for the synthesis of a 135 g, 30%/w batch of PDMAm113 macromolecular chain transfer agent macro-CTA) at 98% conversion. This was used without further purification to polymerise DAAm in a CF reactor. During this polymerisation, the chains underwent polymerisation-induced self-assembly PISA) producing block copolymer spheres. This reaction also proceeded faster than in batch, and the high resolution kinetics enabled clear observation of the rate enhancement which is characteristic of PISA systems. GPC studies indicated the formation of a copolymer with low molar mass dispersity and complete blocking efficiency, despite the high conversion achieved during the precursor macro-CTA synthesis. It was subsequently demonstrated that the PDMAm113 macro-CTA could be used to prepare PDMAm113-PDAAmx block copolymer spheres where x = 50, 100 and 200) with systematically increasing particle diameters. Finally, by reducing the PDMAm macro-CTA DP to 50 and increasing total solids to 20% /w, it was possible to prepare worms and vesicles in the tubular reactor by tailoring the residence time to achieve specific degrees of polymerisation of the PDAAm block.