کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5182959 1381004 2011 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Poly(N-vinylpyrrolidone)-grafted poly(N-isopropylacrylamide) copolymers: Synthesis, characterization and rapid deswelling and reswelling behavior of hydrogels
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Poly(N-vinylpyrrolidone)-grafted poly(N-isopropylacrylamide) copolymers: Synthesis, characterization and rapid deswelling and reswelling behavior of hydrogels
چکیده انگلیسی

Poly(N-isopropylacrylamide)-block-poly(N-vinylpyrrolidone) diblock copolymer (PNIPAAm-b-PVPy) was successfully synthesized via sequential reversible addition-fragmentation chain transfer/macromolecular design via the interchange of xanthate (RAFT/MADIX) process, in which the chain transfer agent of xanthate was in situ afforded via the reaction of isopropylxanthic disulfide (DIP) with 2,2-azobisisobutylnitrile (AIBN). The RAFT/MADIX technique was employed to prepare the poly(N-vinylpyrrolidone)-grafted poly(N-isopropylacrylamide) copolymers (PNIPAAm-g-PVPy) with N,N-methylenebisacrylamide as the crosslinking agent. The comb-like PNIPAAm-g-PVPy copolymer networks with PVPy as the pendent chains were characterized by means of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS). The hydrogel behavior of PNIPAAm-g-PVPy networks was investigated in terms of swelling, deswelling and reswelling tests. With the inclusion of PVPy chains, the swelling ratios of the hydrogels were significantly enhanced compared to the control PNIPAAm hydrogel. It is found that the PVPy-modified PNIPAAm hydrogels displayed faster response to the external temperature changes than the control PNIPAAm hydrogel. The improved thermoresponsive properties of hydrogels are ascribed to the formation of the comb-like architectures in the copolymer networks.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 52, Issue 10, 4 May 2011, Pages 2340-2350
نویسندگان
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