中空乳胶粒子的制备——碱处理

PREPARATION OF HOLLOW LATEX PARTICLES-ALKALI TREATMENT

通过间歇无皂种子乳液聚合 ,制得具有一定交联度的聚 (苯乙烯 (St) -丙烯酸丁酯 (BA) -甲基丙烯酸 (MA) )复合乳液。将稀释后的乳液进行碱 -酸阶段处理 ,得到了粒度均一的、中空结构的乳胶微粒。主要研究了在碱处理过程中 p H值、温度、时间对粒子的空径 (粒子中空的大小 )、粒径及表面羧基含量的影响。结果表明 ,碱处理条件为 p H=12 .5,t=3h。

Hollow latex particles were synthesized by seeded emulsion polymerization, thus, a seed latex consisting of styrene(St), butyl acrylate(BA) copolymer was first prepared, and seeded terpolymerization of St BA MA(methacrylic acid) with divinely benzene as cross linking agent were then carried out in the absence of surfactant. Final latex was then treated by a two step treatment under alkaline and acidic conditions, particles with hollow structure were obtained. The effect of initial pH value, temperature and time in the process of alkali treatment the first step in the information of the hollow structure within the paritcles on the diameter, the hollow size and the amount of surface carboxylic group of latex particles were studied. The results show that hollow latex particles with the largest hollow size can be obtained in a certain condition(pH 12.5, temparature 90 ℃, time 3 h).