聚对苯甲酰胺液晶态球晶生长机理

本文用热台偏光显微镜和透射电子显微镜研究了聚对苯甲酰胺(PBA)/H_2SO_4液晶态生长球晶的形态结构和结晶机理。结果表明,PBA/H_2SO_4向列型液晶相具有过冷状态,可达30—40℃左右,并可生长球晶结构,一般直径可达5毫米左右。20Wt％溶液在不同的过冷态结晶时,可以生成三种形态的球晶结构,这是由于构成球晶的基本结构单元——有序微区结构在不同过冷条件下堆砌排列的规整程度不同的缘故。球晶的形态结构只与过冷程度有关,而与溶液的浓度无关。同时还研究了变温和剪切应力下结晶的球晶形态。

SPHERULITE GROWTH MECHANISM OF POLY-p-BENZAMIDE FROM NEMATIC LIQUID CRYSTALLINE PHASE

Morphology and growth mechanism of spherulite crystallized from nematic mesophase of poly-p-benzamide in 100% H2SO4 have been studied by hot-stage polarizing microscopy and transmission electron microscopy. It is shown that nematic mesophase of PBA possesses a- supercooled state. The degree of supercooling reached 30-40℃ whereby spherulites were formed. It was found that there are three types of PBA spherulites formed from a 20 wt% solution. The orientational arrangments of domains which play the role of fundamental structural units of PBA spherulite are different when spherulites are formed from various supercooled states of the nematic mesophase. The morphology of PBA spherulites has been found to be dependent on the degree of supercooling only, being independent of the concentration of the solution. Various growth mechanisms of PBA spherulites have been discussed.