Abstract

pH-/temperature-sensitive ampholytic poly(N-isopropylacrylamide) (PNIPAAm) hydrogels containing N-[3-(dimethylamino)propyl]methacrylamide-itaconic acid (DMAPMAAm-IA) and DMAPMAAm-AMPS (2-acrylamido-2-methylpropane sulfonic acid) comonomer pairs have been designed and then synthesized. The results showed that (i) disk diameters and transparencies in the range of pH 2–12 increased only with increasing content of AMPS in the ampholytic NIPAAm/DMAPMAAm/AMPS hydrogels containing 10.0 mol % of DMAPMAAm + AMPS mixtures; (ii) maximum compressive strengths of NIPAAm/IA (62.5 ± 10.0 kPa) was higher than NIPAAm/AMPS (26.9 ± 1.1 kPa) hydrogels in DDW at 37 °C. (iii) In case of DFNa release, the decreasing values of n (≈0.30–0.50) indicated that ampholytic PNIPAAm hydrogels served as diffusion barrier.

摘要

含有 N-[3-(二甲基氨基)丙基]甲基丙烯酰胺-衣康酸 (DMAPMAAm-IA) 和 DMAPMAAm-AMPS (2-丙烯酰胺-2-甲基丙烷磺酸) 的 pH-/温度敏感性两性聚 (N-异丙基丙烯酰胺) (PNIPAAm) 水凝胶酸）共聚单体对已被设计并合成。结果表明，(i) 在含有 10.0 mol% DMAPMAAm + AMPS 混合物的两性 NIPAAm/DMAPMAAm/AMPS 水凝胶中，圆盘直径和透明度在 pH 2-12 范围内仅随着 AMPS 含量的增加而增加；(ii) 在 37 °C 的 DDW 中，NIPAAm/IA (62.5 ± 10.0 kPa) 水凝胶的最大抗压强度高于 NIPAAm/AMPS (26.9 ± 1.1 kPa) 水凝胶。(iii) 在 DFNa 释放的情况下，n 的减小值（≈0.30-0.50）表明两性 PNIPAAm 水凝胶充当扩散屏障。