کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5210274 1382883 2013 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Rheological studies on PNIPAAm hydrogel synthesis via in situ polymerization and on resulting viscoelastic properties
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Rheological studies on PNIPAAm hydrogel synthesis via in situ polymerization and on resulting viscoelastic properties
چکیده انگلیسی
Bulk poly(N-isopropylacrylamide) hydrogels were prepared via free radical polymerization. Two different initiation methods were studied: redox- and photoinitiation. It was demonstrated that the desired final properties of resulting hydrogels, i.e., high monomer conversion (>95%) and adjustable swelling were only obtained by selecting best suited initiation conditions. For redox polymerization, this was achieved by tuning the ratio of accelerator N,N,N′,N′-tetramethylethylenediamine to initiator ammonium persulfate. The key parameters for achieving optimum photopolymerization conditions were photoinitiator concentration and UV irradiation time. With help of in situ rheological measurements, optimum conditions could be further verified and quantified by monitoring the liquid-to-gel transition. Overall, photoiniated crosslinking copolymerization was postulated to offer better options for in situ preparation of tailored functional hydrogels, in particular for the integration of smart soft matrices within membrane pores or other microsystems via a rapid reaction. Rheology was also used to investigate the hydrogel after ex situ preparation, revealing “perfect” soft-rubbery behavior. A good correlation between the mesh sizes determined from swelling and rheology was also found. In conclusion, rheology has been found to be a powerful tool because it provides valuable data on polymerization and gelation kinetics as well as information about the hydrogels microstructure based on their viscoelastic character.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Reactive and Functional Polymers - Volume 73, Issue 1, January 2013, Pages 141-148
نویسندگان
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