羧酸盐类成核剂在聚2,6-萘二甲酸乙二酯中的化学成核

CHEMICAL NUCLEATION OF CARBOXYLIC SALT NUCLEATING AGENT IN POLY(ETHYLENE 2,6-NAPHTHALATE)

采用与PEN分子结构单元相似的 2 ,6 萘二甲酸二甲酯 (DMN)和熔点较低的邻氯苯甲酸钠 (SOCB)为模型化合物 ,用DSC、FTIR、带热台偏光显微镜 (HPOM)和HPLC等方法 ,研究了DMN和SOCB在热处理过程中的化学反应 .DSC和HPOM研究也证明了PEN与SOCB在高温下发生化学反应 .因而提出羧酸盐类成核剂在PEN中的成核是“化学成核” .即在高温下羧酸盐类成核剂和PEN发生化学反应 ,生成PEN的羧端基离子盐 ,该离子盐是真正的成核剂 。

Dimethyl 2, 6-naphthalate ( DMN) and sodium of o-chlorobenzoate ( SOCB) were used as model compounds to simulate the chemical reaction between poly(ethylene naphathalate) (PEN) and carboxylic acid alkali salt; and the reaction was studied by using DSC, polarized optical microscopy with a hot-stage ( HPOM), Fourier transform infrared spectrometry( FTIR) and high performance liquid chromatography ( HPLC). By means of DSC and HPOM, the reaction between PEN and SOCB was also proved at high temperature. Therefore, the chemical nucleation mechanism of carboxylic acid alkali salts in PEN was proposed. Carboxylic acid alkali salt reacts with the ester linkages of PEN at high. temperature and PEN ionic chain-ends were produced. The ionic chain-ends act as a true nucleating agent to improve the crystallization rate of PEN.