A novel monomer, N-(2-((3-morpholine-3-isopropyl)thio)ethyl)methacrylamide (MTMA), is synthesized and polymerized by reversible addition-fragmentation chain transfer (RAFT) polymerization to give a thermoresponsive polymer poly[N-(2-((3-morpholino-3-oxopropyl)thio)ethyl)methacrylamide] (PMTMA). PMTMA exhibits reversible thermoresponsive phase transitions of the lower critical solution temperature (LCST) type in water and the upper critical solution temperature (UCST) type in ethanol and methanol. The degree of polymerization and concentration of PMTMA, and solvent type have a significant influence on the transition temperature. PMTMA shows complicated thermoresponse in water–alcohol mixtures. In water–ethanol mixtures, the phase diagram of PMTMA can be divided into three regions according to ethanol volume percentages, φ: 0 ≤ φ < 15% for an LCST region; 15% ≤ φ < 91.5% for a complete dissolution region; 91.5% ≤ φ ≤ 100% for a UCST region. At high water content, the LCST increases with increasing ethanol content; and at high ethanol content, the UCST decreases with increasing water content. In water–methanol mixtures, PMTMA shows more complex thermoresponse. In the range of 0–50 °C, the phase diagram can be divided into five regions, depending on the methanol volume percentages φ: 0 ≤ φ < 15% for LCST region; 15% ≤ φ < 25% for immiscible region; 25% ≤ φ < 85% for UCST region; 85% ≤ φ < 95% for fully dissolved region; 95% ≤ φ ≤ 100% for another UCST region.

中文翻译：

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聚[N-(2-((3-吗啉基-3-氧代丙基)硫代)乙基)甲基丙烯酰胺]的合成：一种在水和酒精溶液中具有可调LCST和UCST型相变的新型热响应聚合物

合成了一种新型单体N- (2-((3-吗啉-3-异丙基)硫代)乙基)甲基丙烯酰胺(MTMA)，并通过可逆加成-断裂链转移(RAFT)聚合得到热响应性聚合物聚[ N- (2-((3-吗啉基-3-氧代丙基)硫基)乙基)甲基丙烯酰胺](PMTMA)。PTMMA 在水中表现出下临界溶解温度 (LCST) 类型，在乙醇和甲醇中表现出上临界溶解温度 (UCST) 类型的可逆热响应相变。PTMMA 的聚合度和浓度以及溶剂类型对转变温度有显着影响。PTMMA 在水-醇混合物中表现出复杂的热响应。在水-乙醇混合物中，PMTMA的相图根据乙醇体积百分比可分为三个区域，φ：0≤φ   <15%为LCST区域；15% ≤  φ  < 91.5% 为完全溶解区域； 对于 UCST 区域，91.5% ≤  φ ≤ 100%。在高含水量时，LCST随着乙醇含量的增加而增加；在高乙醇含量下，UCST随着水含量的增加而降低。在水-甲醇混合物中，PMTMA 显示出更复杂的热响应。在0~50℃范围内，根据甲醇体积百分比φ的不同，相图可分为5个区域：0≤φ   <15%为LCST区域； 不混溶区15% ≤  φ < 25%； UCST 区域25% ≤  φ < 85%；85% ≤  φ  < 95% 为完全溶解区域；对于另一个 UCST 区域， 95% ≤  φ  ≤ 100%。