处理方式及升温速率对液晶热处理性能及动力学的影响

EFFECT OF TREATMENT METHOD AND HEATING RATE ON HEAT TREATMENT PERFORMANCE AND KINETICS OF LIQUID CRYSTAL

针对常用液晶面板内液晶(TV、NB液晶)的热处理特性进行研究,分析了处理方式及升温速率对液晶热处理性能及动力学的影响。结果表明:液晶热处理过程可分为初始失重阶段(130~183℃)、有机物剧烈分解转化阶段(183~400℃)和缓慢失重阶段(400~600℃);升温速率由10℃/min提高至30℃/min时,热解、焚烧条件下TV液晶样品综合热处理性能指数分别缩小了41.28%、56.64%,NB液晶则分别缩小了45.94%、55.79%,说明较低的升温速率能有效促进液晶的热处理性能,同时,NB液晶综合热处理特性指数均低于TV液晶,说明NB液晶热处理性能略低于TV液晶;FTIR显示在1639,1470 cm^(-1)处的官能团吸收峰TV液晶透过率明显高于NB液晶,C=C和C—H含量的差异是导致2类液晶表现出不同热处理特性的原因。在升温速率提高的过程中,热解、焚烧时的TV液晶活化能分别提高了9.7,12.22 kJ/mol,NB液晶则分别提高了18.7,28.72 kJ/mol,这说明较高的升温速率会提高活化能,进而抑制液晶热处理反应。

The heat treatment characteristics of liquid crystal(TV、NB liquid crystal)in common LCD panels were studied,and the effects of treatment methods and heating rate on the heat treatment performance and kinetics of liquid crystal were analyzed.The results show that the heat treatment process of liquid crystal can be divided into initial weight loss stage(130~183℃),violent decomposition and transformation stage(183~400℃)and slow weight loss stage(400~600℃).When the heating rate was increased from 10℃/min to 30℃/min,the comprehensive heat treatment performance indexes of TV liquid crystal samples under pyrolysis and incineration conditions were reduced by 41.28%and 56.64%,respectively,while those of NB liquid crystal were reduced by 45.94%and 55.79%,respectively,indicating that low heating rate could effectively promote the heat treatment performance of liquid crystal.At the same time,the comprehensive heat treatment performance indexes of NB liquid crystal were lower than those of TV liquid crystal,indicating that the heat treatment performance of NB liquid crystal was slightly lower than that of TV liquid crystal.FTIR showed that the transmittance of TV liquid crystal at 1639 cm^(-1)and 1470 cm^(-1)was significantly higher than that of NB liquid crystal.The difference of C=C and C—H content was the reason for the different heat treatment characteristics of the two kinds of liquid crystals.The activation energy of TV liquid crystal increased by 9.7 kJ/mol and 12.22 kJ/mol respectively during pyrolysis and incineration,while NB liquid crystal increased by 18.7 kJ/mol and 28.72 kJ/mol respectively,which indicated that higher heating rate would increase the activation energy and inhibit the heat treatment reaction of liquid crystal.