以苯乙烯(St)、含香豆素光敏单体(VM)、丙烯酸(AA)为单体,偶氮二异丁腈(AIBN)为引发剂引发自由基共聚,合成了双亲性光敏无规共聚物P(St-co-VM-co-AA)(简称PSVA);又以St及甲基丙烯酸二甲胺乙酯(DMAEMA)为单体,AIBN为引发剂引发自由基共聚,制得二元双亲性无规共聚物P(St-co-DM)(简称PSDM)。用凝胶渗透色谱及核磁共振氢谱对聚合物进行了表征;双亲性聚合物PSVA以及PSDM分别在选择性溶剂N,N-二甲基甲酰胺-水中自组装形成阴离子PSVA胶束和阳离子PSDM胶束,通过激光粒度分析仪和Zeta电位仪研究了两种胶束按不同质量配比复配所得复合胶束的粒径及电位;以不同复合配比所得复合胶束作为颗粒乳化剂,制备甲苯-水乳液,用数码照片和光学显微镜表征乳状液以及乳液滴形貌。结果表明:水相体系中,阴离子PSVA和阳离子PSDM胶束按不同质量配比复合可得到不同的复合胶束PSVA-PSDM溶液,改善了单一体系的乳化性,且当w(PSDM)=24.2%时复合胶束达到等电点,当w(PSDM)=33.3%时乳化效果最好;紫外光交联得到的交联PSVA胶束(CL-PSVA),与PSDM复配后的复合胶束CL-PSVA-PSDM可作为乳化剂改善PSVA-PSDM复合胶束所制备乳液的稳定性。
A new amphiphilic random copolymer P(St-co-VM-co-AA),referred to PSVA,was synthesized using styrene(St),photosensitive monomer 7-(4-vinylbenzyloxyl)-4-methylcoumarin(VM) and(acrylic) acid(AA) through free radical copolymerization.Using St and methacrylic acid 2-(dimethylamino) ethyl ester(DMAEMA) as monomer,another amphiphilic random copolymer P(St-co-DM),referred to PSDM was synthesized.These copolymers were characterized by gel permeation chromatography(GPC) and proton nuclear magnetic resonance(~1H-NMR). PSVA anionic micelles and PSDM cationic micelles were prepared with copolymer PSVA and PSDM via self-assembly method in selective solution(DMF-H_2O),(respectively).Complex micelles were generated by mixing the anionic and cationic micelles together.DLS and Zeta potential investigations showed that the size and surface charge of the complex micelles(varied) with the mixing ratio of anionic and cationic micelles.Emulsions were prepared by equal volume(toluene) and water,using complex micelles of PSVA-PSDM as Pickering emulsifier of varied mass ratios.Photographs of the vessels were taken with digital camera and droplet sizes were shown by light microscopy.Finally,a variety of complex micelles were prepared by controlling mass ratios of anionic(micelle) and cationic micelle.Compared to either single PSVA anionic micelle or PSDM cationic micelle,the emulsification effect of complex micelles PSVA-PSDM were increased,especially when w(PSDM) was 33.3%.And when w(PSDM) was 24.2%,Zeta potential of complex micelles solution was zero.Furthermore,cross-linked PSVA anionic(micelles)(CL-PSVA) were obtained by photo-dimerization of the pendant coumarin groups in PSVA under UV irradiation.The emulsion produced by the complex micelles CL-PSVA-PSDM as emulsifiers showed(even) better stability upon standing.