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›› 2011, Vol. 11 ›› Issue (2): 343-348.

• 材料工程专栏 • Previous Articles     Next Articles

Distribution of Carboxyl Groups in Monodispersed Poly(N-Isopropylacylamide-co-Acrylic Acid) Microspheres Prepared by Membrane Emulsification

SI Tian-bao QIN Jia WANG Yu-xia MA Guang-hui   

  1. State Key Lab of Biochemical Engineering, Institute of Process Engineering, CAS Chemical Engineering College of Inner Mongolia University of Technology State Key Lab of Biochemical Engineering, Institute of Process Engineering, CAS State Key Lab. Biochem. Eng., Inst. Process Eng., Chinese Academy of Sciences
  • Received:2011-03-09 Revised:2011-03-30 Online:2011-04-20 Published:2011-04-20
  • Contact: SI Tian-bao

膜乳化法制备尺寸均一P(NIPAM-co-AAc)微球及其羧基分布

司天保 秦佳 王玉霞 马光辉   

  1. 中国科学院过程工程研究所生化工程国家重点实验室 内蒙古工业大学化工学院 中国科学院过程工程研究所生化工程国家重点实验室 中国科学院过程工程研究所生化工程国家重点实验室
  • 通讯作者: 司天保

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Abstract: Temperature-/pH-responsive monodispersed poly(N-isopropyl acrylamide-co-acrylic acid) [P(NIPAM-co-AAc)] microspheres were prepared by Shirasu porous glass membrane emulsification at room temperature with N,N,N￠,N￠-tetramethylethylenediamine as accelerator and cyclohexane/trichloromethane mixture as oil phase. The monodispersed P(NIPAM-co-AAc) microspheres with controllable diameter could be reproducibly obtained with cyclohexane-trichloromethane mixture (volumetric ratio 7:3) as oil phase and two stage stirring speeds (140 and and 170 r/min) under the membrane emulsification pressure of 2 kPa. Conductometric titration was used to determine the distribution of carboxyl groups in the microspheres. Four-step titration curves of all the P(NIPAM-co-AAc) microspheres with different acrylic acid contents were obtained. With the increase of AAc content, the amounts of both exterior carboxyl and embeded carboxyl groups increased gradually, but the percentage of exterior carboxyl groups increased firstly, then remained at a fixed value. The highest percentage of exterior carboxyl groups was obtained with 15%(w) acrylic acid in the microspheres.

Key words: P(NIPAM-co-AAc) microsphere, conductometric titration, carboxyl groups, membrane emulsification

摘要： 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2 kPa、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170 r/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.

关键词: P(NIPAM-co-AAc)微球, 电导滴定, 羧基, 膜乳化法