摘要
以丙烯酰胺(AM)和丙烯酸(AA)单体的水溶液为分散相,失水山梨醇单油酸脂(Span80)/聚氧乙烯失水山梨醇脂肪酸脂(Tween80)/异辛烷为分散介质,分别以N,N′-亚甲基双丙烯酰胺(MBA)、过硫酸铵/亚硫酸氢钠((NH4)2S2O8/NaHSO3)为交联剂和氧化还原引发剂,在30℃进行反相微乳液聚合制备了一系列不同单体摩尔百分数的P(AM-co-AA)微凝胶.通过傅立叶红外光谱、浊度法、透射电镜(TEM)和动态光散射(DLS)等测试手段分别对微凝胶特征官能团的存在、pH敏感性、微观形态、粒径大小及粒径分布等进行表征分析.结果表明,共聚物中存在AM和AA结构单元;样品的TEM照片显示在原料中AA的摩尔百分数为60%时,P(AM-co-AA)微凝胶粒子的数均粒径为90 nm左右,呈现非规则球形;DLS结果表明,P(AM-co-AA)微凝胶与PAM微凝胶相比具有较宽的粒径分布,且随原料中AA摩尔百分数增加,粒径分布逐渐变宽;P(AM-co-AA)微凝胶具有良好的pH敏感性,敏感pH值与AA的解离常数有关,通过调节pH值可以迅速控制自身体积的溶胀与收缩.
A
A series of poly（acrylamide-acrylic acid） microgels with different mole percentages of monomers,based on acrylamide（AM）,acrylic acid（AA） have been prepared by inverse microemulsion polymerization.Aqueous solutions of AM and AA were used as the dispersed phase for microemulsion with Span80/Tween80/isooctane solution as the dispersion medium.The polymerization was carried out at 30℃ in the presence ofNH42S2O8/NaHSO3 and （N,N′-methylenebisacrylamide）（MBA） as the oxidation-reduction initiator and crosslinker,respectively.The presence of characteristic functional groups,pH-sensitive behavior,morphology,particle sizes and distribution of microgels have been characterized through Fourier transform infra red spectroscopy（FTIR）,turbidimetric method,transmission electron microscopy（TEM） and dynamic light scattering（DLS）.FTIR studies confirm the occurrence of AM and AA construction units within the macromolecular chains of microgels.TEM photographs of microgels show that particle number-average diameter of P（AM-co-AA） microgels with the mole percentage of AA 60% in the feed is about 90 nm,so they have large specific surface area.Comparing with PAM micogels,the spherical morphology of P（AM-co-AA） microgels are not very regular due to shrinking during drying operation.Moreover,DLS shows that particle sizes of microgels are increasing and the size distribution of microgels becomes slightly wider with increasing of mole percentage of AA in the feeds.Investigations of turbidimetric method suggest that P（AM-co-AA） microgels are provided with pH-sensitive behavior because of the presence of AA in the feed,and the sensitive pH value is related to the dissociation constant of AA.Due to their interesting properties,P（AM-co-AA） microgels will have a number of potential applications such as drug delivery,adsorption of heavy metal ions and so on.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2009年第9期917-921,共5页
Acta Polymerica Sinica
基金
山西省青年基金(基金号20031018)
山西省科技攻关项目(项目号2006031139)资助
作者简介
通讯联系人，E—mail：shenyinghua@tyut．edu．cn
