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
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
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.
司天保 秦佳 王玉霞 马光辉. 膜乳化法制备尺寸均一P(NIPAM-co-AAc)微球及其羧基分布[J]. , 2011, 11(2): 343-348.
SI Tian-bao QIN Jia WANG Yu-xia MA Guang-hui. Distribution of Carboxyl Groups in Monodispersed Poly(N-Isopropylacylamide-co-Acrylic Acid) Microspheres Prepared by Membrane Emulsification. , 2011, 11(2): 343-348.