方差方法用于高聚物X光衍射峰形的分析

APPLICATION OF VARIANCE METHOD TO THE ANALYSIS OF X-RAY DIFFRACTION PROFILES FOR POLYMER

假设PET纤维中的晶格畸变可用次晶模型描述,用其x光衍射105的方差-区间函数测定出一组热处理样品的晶粒尺寸和晶格畸变因子。说明了此法所得晶粒尺寸为“数均”尺寸。发现样品中晶区的完善性随其热处理温度的升高而改善;晶粒尺寸与畸变因子之间的关系符合Hosemann的a~*定则。

The crystallite sizes and degrees of lattice distortion of annealed PET fibers have been determined with the variance-range functions of 105 diffraction profile with the assumption that the crystallites in the materials are paracrystalline. The corrections of the diffraction profile data were simple and reliable because there was not any overlapping with other reflexions in tie range of 2θ=35°—51°. It has been shown that: (1) the use of the variance-range function for the determination of crystallite size results in a "number-average" size;(2) annealing produces larger crystallite sizes and smaller degrees of lattice distortion.