Comparative study of the behavior of carboxymethyl cellulose-g-poly(N-isopropylacrylamide) copolymers and their equivalent physical blends
- 作者：Vasile ; Cornelia ; Bumbu ; Gina Gabriela ; Petronela Dumitriu ; Raluca ; Staikos ; G.
- 关键词：Graft copolymers ; Equivalent blends ; Viscometry ; Turbidimetry
- 刊名：European Polymer Journal
- 出版年：2004
- 期刊代码：35_00143057
- 类别：ms
- 出版时间：June, 2004
- 卷：40
- 期：6
- 页码：1209-1215
- 文件大小：320 K
摘要
A comparative study of the behavior of carboxymethyl cellulose and poly(N-isopropylacrylamide) (PNIPAM) as graft copolymers and physical blends, in solution and in solid state was accomplished by viscometry, turbidimetry, IR spectroscopy, X-ray diffraction, thermogravimetry, and enzymatic degradation. Both in diluted and concentrated solutions, the graft copolymers exhibited a thermothickening effect, while the corresponding mixtures of the two components exhibited an Arrhenius behavior. Solid phase investigations showed morphological differences between graft copolymers and their equivalent physical blends. The enzymatic degradation behavior is essentially similar both for copolymers and blends (enzymatic degradation activity has similar values) although a slight increased enzymatic activity was noticed for the graft copolymers in comparison with the blends.