Kinetic study on thermal decomposition of GFRP under γ irradiation

doi:10.11949/j.issn.0438-1157.20180175

Abstract

Abstract:

Glass fiber reinforced plastic (GFRP) is used as support material for high energy physics and nuclear physics experiments due to its excellent thermal insulation and mechanical performance. High-energy physics and nuclear physics experiments produce large amounts of γ and neutron irradiation to the support material. In order to ensure the stability of GFRP under γ-irradiation conditions, the kinetic model of pyrolysis needs to be establish to calculate the activation energy under different irradiation doses. The obtained results show that the pyrolysis process of GFRP in a nitrogen atmosphere can be divided into three stages, the main mass loss stage occurs at 200-470℃. With the increase of radiation dose, the mass loss rate of GFRP increased. After 20, 100 and 200 kGy γ irradiation, the mass loss rate of GFRP increased from 31.1% to 32.7%, 35.5% and 37.5%, respectively, by 2%, 3.9% and 4.4%. With the heating rate increased the mass loss rate increased significantly. After 200 kGy γ irradiation, the average activation energy of GFRP calculated by Friedman method was increased from 96.1 kJ·mol^-1 to 116.6 kJ·mol^-1, which increased by 21.3%. The average activation energy of GFRP calculated by FWO method was increased from 107.6 kJ·mol^-1 to 125.4 kJ·mol^-1, which increased by 16.5%. Microstructure analysis by SEM found that the binding degree of the glass fiber and the epoxy declines after γ irradiation, differential scanning calorimetry indicates that the curing reaction occur of epoxy in the irradiation process.

Key words: GFRP, pyrolysis, activation energy, &gamma, irradiation, composites, thermodynamics

摘要：

玻璃纤维增强塑料（GFRP）因其良好的热绝缘性能和力学性能，在高能物理和核物理实验领域被用来制作支撑设备，而高能物理和核物理实验会对其支撑设备产生一定的γ和中子辐照，为保证GFRP支撑设备在γ辐照条件下的结构稳定性，需研究辐照对其热分解性能的影响。结果表明，GFRP在氮气氛围中的热分解可分为3个阶段；GFRP失重率随辐照剂量的增大而增大；辐照使GFRP的活化能增加，Friedman法计算得出平均活化能由辐照前的96.1 kJ·mol^-1增加到200 kGy辐照后的116.6 kJ·mol^-1，Flynn-Wall-Ozawa（FWO）法计算得出平均活化能由辐照前的107.6 kJ·mol^-1增加到200 kGy辐照后的125.4 kJ·mol^-1。扫描电镜对微观形貌观察发现辐照后环氧树脂与玻璃纤维结合度降低，差示扫描量热法分析得出辐照使环氧树脂进一步固化反应。

关键词: GFRP, 热解, 活化能, γ辐照, 复合材料, 热力学

CLC Number:

TB332
TL349

ZHENG Lifang, WANG Zhaozhong, XIE Yajie, YUE Lina, WANG Li. Kinetic study on thermal decomposition of GFRP under γ irradiation[J]. CIESC Journal, 2018, 69(S1): 161-169.

郑莉芳, 王兆中, 谢亚杰, 岳丽娜, 王立. γ辐照作用下GFRP热分解动力学研究[J]. 化工学报, 2018, 69(S1): 161-169.

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