同步辐射X光散射方法研究聚苯硫醚(PPS)的结晶动力学

Investigation of Crystallization of PPS by Employing Synchrotron Radiation

本文报道了用同步辐射X光散射方法研究聚苯硫醚(PPS)等温过程结晶动力学,测定了在不同结晶温度Tc下,小角和广角散射强度曲线、散射峰极大值随结晶温度的升高而向小角度移动。由小角和广角测得的一系列不同Tc温度的时间解析谱图,计算出PPS结晶速度(?)1/2最小值为0.47min,相对应的Tc为189℃,低于100℃和高于250℃结晶速度极为缓慢。长周期随结晶温度升高而增大,接近250℃时减小;密度随结晶温度升高而增加,接近熔融时,则有较大的增加;由PPS 30～225℃之间Q随温度变化曲线上的折点,求出T_g=89±5℃(加热速度10℃/min);并计算出在T_g温度时PPS两相热膨胀系数差为:

This papar is about the investigation of the isothermal crystallization process by means of the X-ray scattering of synchrotron radiation. Through experiments, we determined the curve of small and wide angles scattering intensity and maximum of scattering peak moved to smaller angle as the crystallization temperature goes high. From the resolution charts which were gained different Tc temperature from the determination of PPS SAXs and WAXS, one can calculate the smallest value of PPS crystallization speed (t1/2) which is 0.47 min and corresponds to Tc temperature 189℃. The crystallization speed is rather slow at temperature below 100℃ and above 250℃. Long Period increases as the temperature goes high and goes down. When the temperature goes near to 250℃, the result of determining density tells us the density can increase greatly. From the break-point on the Q-T curve in the range of 30-225℃ one can find out Tt temperature of PPS is 89 ± 5℃ (heating speed is 10℃/min). According to formula (3) at Tg temperature, the difference of the thermal expansion coefficient of PPS between crystals and amorphous regions is delta alpha, Δa' = (a -ac') = (0.76+ 0.03) ×10-2℃-1.