Studies on curing kinetics of a novel combined liquid crystalline epoxy containing tetramethylbiphenyl and aromatic ester‐type mesogenic group with diaminodiphenylsulfone |
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| Authors: | Zhi‐Qi Cai Jianzhong Sun Daodeng Wang Qiyun Zhou |
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| Institution: | 1. State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, China;2. State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, ChinaState Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, China |
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| Abstract: | The curing kinetics of a novel liquid crystalline epoxy resin with combining biphenyl and aromatic ester‐type mesogenic unit, diglycidyl ether of 4,4′‐bis(4‐hydroxybenzoyloxy)‐3,3′,5,5′‐tetramethyl biphenyl (DGE‐BHBTMBP), and the curing agent diaminodiphenylsulfone (DDS) was studied using the advanced isoconvensional method (AICM). DGE‐BHBTMBP/DDS curing system was investigated the curing behavior by means of differential scanning calorimetry (DSC) during isothermal and nonisothermal processes. Only one exothermal peak appeared in isothermal DSC curves. A variation of the effective activation energy with the extent of conversion was obtained by AICM. Three different curing stages were confirmed. In the initial curing stage, the value of Ea is dramatically decreased from ～90 to ～20 kJ/mol in the conversion region 0–0.2 for the formation of LC phase. In the middle stage, the value of Ea keeps about ～80 kJ/mol for cooperative effect of reaction mechanism and diffusion control. In the final stage, a significant increase of Ea from 84 to 136 kJ/mol could be caused by the mobility of longer polymer chains. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3922–3928, 2007 |
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| Keywords: | curing kinetics curing of polymers diaminodiphenylsulfone differential scanning calorimetry (DSC) kinetics liquid crystalline epoxy resin liquid‐crystalline polymer mesogenic unit |
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