Mechanical and thermal properties of perfluoroalkyl ethyl methacrylate–methyl methacrylate statistical copolymers synthesized in supercritical carbon dioxide

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• 作者：Ugur Cengiz^a ; ^{ucengiz@gyte.edu.tr"" rel=""nofollow} ; Nevin A. Gengec^a ; N. Ugur Kaya^b ; H. Yildirim Erbil^a ; A. Sezai Sarac^b
• 关键词：Supercritical carbondioxide ; Mechanical properties ; Fluomethacrylate copolymers ; Free volume ; Young's modulus ; Glass transition
• 刊名：Journal of Fluorine Chemistry
• 出版年：2011
• 出版时间：May 2011
• 年：2011
• 卷：132
• 期：5
• 页码：348-355
• 全文大小：475 K

文摘

Poly(methyl methacrylate-ran-perfluoroalkyl ethyl methacrylate) copolymers having varying perfluoroalkyl ethyl methacrylate ester (Zonyl-TM) contents were synthesized in supercritical CO₂. Complete amorphous structures of the copolymers were verified by XRD. Young's modulus (Y_mod) of the copolymers was decreased linearly from 1.57 to 1.08 GPa and T_g values from 102 to 77 °C with the increase of Zonyl-TM content. A linear relationship between the Y_mod and the T_g values of the copolymer was also found. The increase of the large branched pendant groups resulted in the increase of the free volume and a corresponding decrease in Y_mod and T_g of the copolymers. A good fit was found when the Schneider equation was used. Negative deviation from the Gordon–Taylor equation was observed when Zonyl-TM content was lower than 14 % due to rapid increase in free volume and then a positive deviation was found due to the dipole–dipole interactions between the methyl ester and fluoroalkyl ester groups.