Fast Responsive Poly(acrylic acid-co-N-isopropyl acrylamide) Hydrogels Based on New Crosslinker

作者：Atta Ayman M^*; Abdel Bary E M; Rezk Kamel; Abdel Azim A

来源：Journal of Applied Polymer Science, 2009, 112(1): 114-122.

DOI：10.1002/app.28950

• hydrogels
• pH- and temperature sensitive gels
• N-isopropylacrylamide
• melamine triacrylamide crosslinkers

Novel dual temperature- and pH-sensitive poly(acrylic acid-co-N-isopropylacrylamide), AA/NIPAAm, hydrogels were successfully prepared by chemical crosslinking with crosslinkers. Copolymers of AA/NIPAAm were crosslinked in the presence of different mol % of N,N-methylene bisacrylamide (MBA) and melamine triacrylamide (MAAm) as crosslinkers by bulk radical polymerization. The resultant xerogels were characterized by extracting the soluble fractions and measuring the equilibrium water content. Lower critical Solution transition temperatures (LCST) were measured by DSC. The properties of crosslinked AA/NIPAAm series are evaluated in terms of compositional drift of polymerization, heterogeneous crosslinking, and chemical structure of the relevant components. Soluble fractions of the crosslinked networks were reduced by varying the MAAm and MBA concentrations. The influence of environmental conditions such as temperature and pH on the swelling behavior of these polymeric gels was investigated. The swelling behaviors of the resulting gels show pH sensitivity. The prepared MAAm type AA/NIPAAm hydrogels exhibited a more rapid deswelling rate than MBA type AA/NIPAAm hydrogels in ultra pure water in response to abrupt changes from 20 degrees C to 50 degrees C. The results of this Study provide valuable information regarding the development of dual stimuli-sensitive hydrogels with fast responsiveness.

• 出版日期2009-4-5