Polymethacrylamide—An underrated and easily accessible upper critical solution temperature polymer: Green synthesis via photoiniferter reversible addition–fragmentation chain transfer polymerization and analysis of solution behavior in water/ethanol mixtures,Journal of Polymer Science

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Polymethacrylamide—An underrated and easily accessible upper critical solution temperature polymer: Green synthesis via photoiniferter reversible addition–fragmentation chain transfer polymerization and analysis of solution behavior in water/ethanol mixtures
Journal of Polymer Science ( IF 3.9 ) Pub Date : 2020-09-18 , DOI: 10.1002/pol.20200566
Tilman Eckert _{1,

2} , Volker Abetz _{1,

2}

Affiliation

Within the group of stimuli‐responsive, “smart” materials, upper critical solution temperature (UCST) polymers remain sparsely investigated. Thus, this work focusses on a vastly ignored UCST polymer: polymethacrylamide (PMAAm). A cost‐efficient photoiniferter reversible addition–fragmentation chain transfer (RAFT) polymerization yielding narrowly dispersed (Đ < 1.1) PMAAm is presented. This PMAAm exhibits highly thermoreversible UCST‐type phase transitions (PT) in water/ethanol mixtures (ethanol content: 17–35 wt%) which are investigated via temperature dependent dynamic light scattering (DLS). Apart from the ethanol content, the PT temperature is affected by polymer mass fraction and chain length and varies between 10–80 °C depending on the three mentioned parameters. Lastly, PMAAm's propensity towards amide hydrolysis and concomitant PT‐suppression is investigated. Below temperatures of 40 °C, PMAAm solutions show no sign of amide hydrolysis for at least three days, however, if heated to 70 °C, the thermoresponsiveness gradually degrades within hours.

中文翻译：

聚甲基丙烯酰胺-一种被低估且易于获得的最高临界溶液温度聚合物：通过光引发剂可逆加成进行的绿色合成-片段链转移聚合以及在水/乙醇混合物中的溶液行为分析

在刺激响应的“智能”材料组中，仍未对上临界溶液温度（UCST）聚合物进行稀疏研究。因此，这项工作的重点是被广泛忽略的UCST聚合物：聚甲基丙烯酰胺（PMAAm）。具有成本效益的光引发剂可逆加成-断裂链转移（RAFT）聚合，产生窄分散的（Đ <1.1）介绍了PMAAm。该PMAAm在水/乙醇混合物（乙醇含量：17-35 wt％）中表现出高度热可逆的UCST型相变（PT），可通过依赖于温度的动态光散射（DLS）进行研究。除乙醇含量外，PT温度还受聚合物质量分数和链长的影响，并且在10–80°C之间变化，具体取决于上述三个参数。最后，研究了PMAAm对酰胺水解和伴随PT抑制的倾向。在低于40°C的温度下，PMAAm溶液至少三天没有显示酰胺水解的迹象，但是，如果加热到70°C，则其热响应性会在数小时内逐渐降低。

更新日期：2020-11-02

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