摘要
报道了一种利用变温的途径制备具有温度敏感性聚合物凝胶微粒的悬浮聚合方法.以正庚烷为连续相,过硫酸铵和四甲基乙二胺为引发剂,采用将具有反向温敏性的可降解大分子单体水溶液在低温下分散好以后再升高到聚合温度的变温反相悬浮聚合的方法制备了反向温敏性的可降解微凝胶.该方法避免了由于分散相在聚合温度下发生物理凝胶化所导致的分散困难等问题.考察了微凝胶的温敏性、粒径分布和降解行为等,并研究了油水比对微凝胶形貌的影响.
An altered-temperature inverse suspension thermosensitive macromers, was presented to prepare polymerization, which was suitable for negatively thermosensitive and biodegradable mierogels. The thermosensitivity and biodegradability of mierogels come from those of maeromers. The mierogels were synthesized in suspension, in which the continuous phase was heptane. Ammonium persulphate and N, N, N＇, N＇- tetramethylethylenediamine were employed as the initiating system. The negatively thermosensitive macromer aqueous solution was first dispersed well at low temperatures （lower than the sol-gel transition temperature of the macromer solution） and then crosslinked after raising temperature. The highlight of this approach is the avoidance of dispersion difficulty of the dispersion phase because of its physical gelation at polymerizing temperature. The thermosensitivity and biodegradation of the resulting microgels were confirmed. The volume phase transition temperature of microgels was around 25℃ ,and the volume of microgels at 37℃ was less than half of that at 4℃ . Microgels were completely degraded into water-soluble products. It was necessary to add aqueous solutions of initiator and accelerator into the continuous phase after raising temperature. The ratio of oil to water influenced the morphology of microgels to a certain degree.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2005年第6期919-923,共5页
Acta Polymerica Sinica
基金
863计划(项目号2004AA215170)
国家自然科学基金(基金号20221402
20374015)
教育部科学技术研究重大项目(项目号305004)
高等学校青年教师教学和科研奖励基金
973计划(项目号G1999054306-03)
上海市科技发展基金(基金号04JC14019)
中国博士后科学基金(基金号2004035115)资助项目
关键词
微凝胶
反向温敏性
可降解
反相悬浮聚合
Microgels, Negative thermosensitivity, Biodegradable, Inverse suspension polymerization
