Influence of the chemical structure on the kinetics of the structural relaxation process of acrylate and methacrylate polymer networks

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• 作者：M. Salmerón Sánchez ; Y. Touzé ; A. Saiter ; J. M. Saiter and J. L. Gómez Ribelles
• 关键词：Structural relaxation ; Glass transition ; DSC ; PEA ; PEMA ; PHEMA
• 刊名：Colloid & Polymer Science
• 出版年：2005
• 出版时间：April 2005
• 年：2005
• 卷：283
• 期：7
• 页码：711-720
• 全文大小：580 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Polymer Sciences
  Physical Chemistry
  Soft Matter and Complex Fluids
  Characterization and Evaluation Materials
  Food Science
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1435-1536

文摘

The enthalpy relaxation of poly(hydroxyethyl methacrylate) (PHEMA), poly(ethyl methacrylate) (PEMA) and poly(ethyl acrylate) (PEA) networks, obtained by DSC, are compared. The temperature interval of the glass transition broadens in the sequence PEA-PEMA-PHEMA. The plots of the enthalpy loss during the annealing for 200 min at different temperatures below T_g show that the structural relaxation process also takes place in PHEMA in a broader temperature interval than in PEA or PEMA. The modelling of the structural relaxation process using a phenomenological model allows determining the temperature dependence of the relaxation times concluding that the fragility in PHEMA is significantly lower than in PEMA. Both features are ascribed to the connectivity of the polymer chains in PHEMA via hydrogen bonding. The role of the presence of the methyl group bonded to the main chain is analysed by comparing the results obtained in PEA and PEMA.