摘要
用液氮淬火和热处理方法制得结晶度相差较大的铁电共聚物VDF(52)/TrFE(48)试样、介电弛豫研究揭示室温以下共聚物的频率谱由低频和高频两部分组成.低频部由非晶区被冻结分子链段的微布朗运动贡献,符合WLF方程;高频部由晶区和非晶区分子链段较小尺度的局域运动产生,遵从Arrhenius规律.分峰拟合结果得到共聚物的玻璃化转变温度为-24℃,局域弛豫活化能为46.4kJ/mol.
Abstract Ferroelectric copolymers VDF(52)/ TrFE(48) with crystallinity of 20% and 60% were prepared by cooling rapidly in liquid nitrogen and annesling at 130℃ for 2hrs. The investigations of dielectric relaxation showed that the frequency spectra of copolymers below room temperature consisted of low-frequency part ascribed to the micro-Brownian motion of molecular segments in the noncrystalline regions and high-frequency part designated as the local motions of small-scale segments. Based on the results of fitting and calculated with WLF equation and Arrhenius formula, We obtained TR(-24℃) and the activation energy of local relaxation(46.4kJ/mol) of copolymers.