Improving the curing process and thermal stability of phthalonitrile resin via novel mixed curing agents |
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Authors: | Zuoqiang Wu Jianhua Han Nan Li Zhihuan Weng Jinyan Wang Xigao Jian |
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Affiliation: | 1. Department of Polymer Science and Materials, Dalian University of Technology, Dalian, China;2. State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, China;3. Liaoning High Performance Resin Engineering Research Center, Dalian University of Technology, Dalian, China |
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Abstract: | High curing temperature (including post‐curing temperature) and long curing time of phthalonitrile resins make them thermally stable but difficult to process. In this paper, novel mixed curing agents (CuCl/4,4′‐diaminodiphenylsulfone (DDS) and ZnCl2/DDS) were firstly designed for solving these problems. Bisphenol‐based phthalonitrile monomer (BP‐Ph; melting point: 228–235 °C) was synthesized and used as the curing precursor. Differential scanning calorimetry results indicated that BP‐Ph cured with CuCl/DDS and ZnCl2/DDS exhibited curing temperatures close to the melting point of BP‐Ph with curing ending temperatures of 225.4 and 287.1 °C, respectively. Rheologic investigations demonstrated obvious curing reactions of BP‐Ph occurred with the mixed curing agents at 220 °C. Thermogravimetric analysis showed that BP‐Ph cured by CuCl/DDS or ZnCl2/DDS maintained 95% mass at 573 or 546 °C, respectively, at a post‐curing temperature of 350 °C for 2 h. Reasonable long‐term thermo‐oxidative stability was also demonstrated. When the post‐curing temperature decreased to 290 °C, char yield at 800 °C of BP‐Ph cured by CuCl/DDS was 77.0%, suggesting the curing procedure can be milder when using mixed curing agents. © 2017 Society of Chemical Industry |
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Keywords: | mixed curing agents phthalonitrile resin curing process thermal stability |
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