缩醛化乙烯醇-丙烯酸钠共聚物的合成及温敏性质

Preparation and Temperature Sensitivity of Acetalyzed Poly(vinyl alcohol-co-sodium acrylate)

首先合成了室温下可溶于水的聚乙烯醇-丙烯酸钠共聚物(PVA-co-AANa),然后部分缩醛后得到一系列不同缩醛度(DA)、不同相对分子质量和单体组成的高分子材料(APVA-co-AANa),该材料具有温敏性。用FTIR和1HNMR表征了其结构。通过APVA-co-AANa水溶液在不同温度的浊度测定,考察了母体PVA-co-AANa相对分子质量、DA和单体组成对APVA-co-AANa的低临界溶解温度(LCST)的影响,发现APVA-co-AANa的DA越高、分子链越长、AA组分用量越小,相对LCST越低。而且,APVA-co-AANa水溶液还表现出盐敏性,LCST随NaCl用量增加而降低。APVA-co-AANa膜的AFM表面形貌的变化也证实了APVA-co-AANa的温敏性。

Poly（ vinyl alcohol-co-sodium acrylate） （PVA-co-AANa） ,which is soluble in water at room temperature,was prepared,and a series of temperature-sensitive acetalyzed PVA-co-AANa （ APVA-co- AANa） with different degrees of acetalation （DA）, chain lengths and contents of comonomer were synthesized. FTIR and ^1HNMR technique were used to analyze their structures. The turbidities of APVA-co-AANa aqueous solutions at different temperatures reveal that their lower critical solution temperatures（LCST） can be affected by the molecular weight of starting PVA-co-AANa, DA and contents of comonomer. Lower LCST is observed when the APVA-co-AANa possesses a longer chain, higher DA or less acrylate content. Besides,the LCSTs of APVA-co-AANa aqueous solutions show salt sensitivity. The LCST decreases with the increase of NaCl concentration. Moreover, the AFM images of APVA-co-AANa also prove their temperature-sensitivity.