小分子氢键给体对羟丙甲基纤维素LCST的影响

Effect of small molecule hydrogen-bond donor on lower critical solution temperature of hydroxypropyl methyl cellulose

文章以丙烯酸(AA)、甲基丙烯酸(MAA)、丙酸(PA)、乙酸(HOAc)、氯乙酸(CA)为模型分子,研究了小分子氢键给体对羟丙甲基纤维素(HPMC)在水中的低临界溶解温度(lower critical solution temperature,LCST)的影响。研究发现LCST与小分子氢键供体的质量分数呈反比关系,进一步研究表明,LCST的变化率与小分子的分子面积、分子体积、羧基的电负性及脂水分配系数(lg P)有密切的关系。

In this paper, acrylic acid（AA）, methacrylic acid（MAA）, propionic acid（PA）, acetic acid （HOAc）, chloroacetic acid（CA） were used as model molecules to study the influence of small mole- cule hydrogen-bond donor on the lower critical solution temperature（LCST） of hydroxypropyl methyl cellulose（HPMC） in aqueous solution. It is found that the LCST and the concentration of small mole- cules hydrogen-bond donor exhibit inversely proportional relationship. Further studies show that the rate of change of the LCST has close relationship with molecular area, molecular volume, carboxyl group eleetronegativity and lipid-water partition coefficient（lg P） of these small molecules.