液晶高分子薄膜的热处理及结晶行为  

Heat treatment and crystallization behavior of liquid crystal polymer films

作　　者：柯霆 韩瑞 朱文祥 姚玉元[1] KE Ting;HAN Rui;ZHU Wenxiang;YAO Yuyuan(National Engineering Laboratory for Textile Fiber Materials&Processing Technology,Zhejiang Sci-Tech University,Hangzhou 310018,China;Zhejiang Hailide New Materials Co.,Ltd.,Jiaxing 314000,China)

机构地区：[1]浙江理工大学纺织纤维材料与加工技术国家地方联合工程实验室,杭州310018 [2]浙江海利得新材料股份有限公司,浙江嘉兴314000

出　　处：《工程塑料应用》2024年第2期123-129,135,共8页Engineering Plastics Application

基　　金：浙江省“尖兵”“领雁”研发攻关计划项目(2022C01197,2023C01203)。

摘　　要：为探究液晶高分子(LCP)薄膜在热处理过程中结晶行为,利用差示扫描量热(DSC)仪对LCP薄膜进行热处理,考察了在不同热处理条件下LCP薄膜熔点和熔融焓的变化,并分析其结晶转变。非等温结晶实验结果表明LCP薄膜熔融后的再结晶快过程难以避免,且形成新晶体的熔融特征与降温速率无关。等温结晶实验结果表明慢过程无法完全抑制快过程,且LCP薄膜经慢过程形成新晶体的温度上限为270℃。不同条件的等温热处理实验结果表明,低温段热处理有利于提高熔融焓,熔程上限以下的高温段热处理则更有利于提高熔点,在240℃等温热处理60 min得到最大熔融焓为3.87 J/g,在290℃等温热处理60 min得到最高熔点为306.8℃。通过分峰定性LCP薄膜在不同热处理温度下的结晶趋势,分析得到慢过程中形成新晶体、原晶体生长(包括熔融-再结晶的晶体)与冷却快过程形成新晶体的最佳温度分别为LCP薄膜的结晶温度、熔程下限温度与熔程上限温度。最终,结合LCP薄膜热处理前后的晶体结构模型,总结LCP薄膜在热处理中的结晶转变,为规模化制备高性能LCP薄膜提供参考。In order to investigate the crystalline behavior of liquid crystal polymer(LCP)films during heat treatment,LCP films were heat-treated using differential scanning calorimetry(DSC),and the changes in melting point and enthalpy were investigated under different heat treatment conditions,and the crystalline transition was analyzed.The results of the non-isothermal crystallization experiments show that the recrystallization fast-processes after the melting of LCP films is difficult to avoid,and that the melting characteristics of new crystals are independent of the cooling rate.The results of isothermal crystallization experiments show that the slow-processes cannot completely inhibit the fast-processes,and the upper temperature limit for the formation of new crystals in LCP films by the slow-processes is 270℃.The results of isothermal heat treatment experiments under different conditions show that heat treatment in the low-temperature section is favorable to increase the melting enthalpy,while heat treatment in the high-temperature section below the upper limit of the melting range is more favorable to increase the melting point.The maximum melting enthalpy is obtained as 3.87 J/g by isothermal heat treatment at 240℃for 60 min,and the maximum melting point is obtained as 306.8℃by isothermal heat treatment at 290℃for 60 min.The crystallization tendency of LCP films at different heat-treatment temperatures was obtained by split-peak-treatment.The optimal temperatures for the formation of new crystals and the growth of original crystals(including melt-recrystallization)in the slow-processes,and the formation of new crystals in the fast-processes were obtained to be the crystallization temperature,the lower limit of the melting range,and the upper limit of the melting range for the LCP films,respectively by analyzing.Ultimately,combining with the crystal structure model of LCP films before and after heat treatment,the crystallization transformation of LCP films during heat treatment was summarized.It can provide

关 键 词：液晶高分子薄膜 差示扫描量热 等温热处理 多重熔融行为 结晶行为 

分 类 号：TQ322.3[化学工程—合成树脂塑料工业]