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采用膜乳化法,以环己烷和氯仿混合溶液为油相,在室温下通过加入加速剂TEMED引发聚合反应,制备了一系列不同丙烯酸含量的P(NIPAM-co-AAc)微球.结果表明,在压力2kPa、环己烷/氯仿体积比7:3、第一和第二阶段过膜搅拌速度分别为140和170r/min的条件下,可制备粒径均一、大小可控、重复性较好的P(NIPAM-co-AAc)微球.用电导滴定法测定微球中羧基分布,所有不同丙烯酸含量的P(NIPAM-co-AAc)微球电导滴定曲线均为4阶梯形状,随其含量增加,微球外层羧基含量和内层包埋的羧基含量均逐渐增加,但外层羧基占总羧基含量比例先增大然后趋于不变,丙烯酸含量为15%时达最大值.
A series of P (NIPAM-co-AAc) microspheres with different acrylic acid contents were prepared by the membrane emulsification method using cyclohexane and chloroform as the oil phase and the polymerization reaction was initiated by adding TEMED at room temperature. , Under the conditions of pressure 2kPa, cyclohexane / chloroform volume ratio 7: 3, the first and second stage membrane-passing stirring speed are 140 and 170r / min respectively, the particle size can be prepared with uniform size, controllable size and repeatability (NIPAM-co-AAc) microspheres.The conductivity distribution of carboxyl groups in the microspheres was determined by conductometric titration. The conductivity curves of all the P (NIPAM-co-AAc) microspheres with different contents of acrylic acid all had a 4-step shape. The contents of carboxyl groups in the outer layer of the microspheres and the carboxyl groups embedded in the inner layer increased gradually, but the proportion of the carboxyl groups in the outer layer first increased and then tended to be unchanged, and reached the maximum value when the content of acrylic acid was 15%.