超临界二氧化碳中一种高分子弱凝胶的制备及性质  

Synthesis of a Novel Weak Gel in Supercritical Carbon Dioxide and Its Properties

作　　者：张怀平[1,2,3] 许凯[1] 陈德宏[1] 许林利[1] 陈嘉[1] 陈鸣才[1] 

机构地区：[1]中国科学院广州化学研究所,广东广州510650 [2]太原理工大学材料科学与工程学院,山西太原030024 [3]中国科学院研究生院,北京100039

出　　处：《高分子材料科学与工程》2009年第5期132-135,共4页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(20474067)

摘　　要：通过改变丙烯酸(AA)与可反应疏水单体甲基丙烯酸-3-三甲氧基硅丙酯(MPS)的投料比,在超临界二氧化碳介质中制备了一系列的AA与MPS共聚物(AA-co-MPS)。采用滴定法、扫描电镜和旋转黏度计对共聚物的组成及性质进行了表征。结果表明,MPS反应活性较丙烯酸高,共聚物形貌是直径约0.5μm左右的球形颗粒。共聚物的溶解试验结果表明,硅氧烷间化学反应形成弱凝胶体系,分子间交联使弱凝胶的黏度随着可反应疏水单体含量增加而增加。共聚物中可反应疏水单体质量百分比含量超过2.1%时,共聚物开始形成沉淀。由于共聚物具有pH敏感性,弱凝胶体系黏度随pH值变化先增加后减少,在pH=5.5出现峰值。Copolymer poly（AA-co-MPS） were synthesized using precipitation polymerization of acrylic acid and methacryloxypropyltrimethoxysilane（MPS） in various molar ratios in supercritical carbon dioxide. The structure and properties of the copolymer were studied by scanning electron microscopy （SEM）, titration, rotational viscometer. The MPS monomer is more active than the AA monomer in reaction. Copolymer morphologies and particle size were determined by SEM. It shows that the diameter of the primary particle is around 0.5μm. The formation of weak gel is the main reason for the increase of the viscosity due to chemical reaction between siloxane. The viscosity of weak gel rises up dramatically with the increase of MPS concentration. Copolymer is not dissolved in water when hydrophobie monomer content in copolymer is above 2.1% （mass percent）. The viscosity of weak gel shows a strong dependence on pH with a maximum at pH= 5.5 owing to copolymer is responsive to pH.

关 键 词：超临界二氧化碳 弱凝胶 表观黏度 PH敏感性 

分 类 号：TQ427.25[化学工程]