高温气相色谱法测定高黏度聚α烯烃的组成

采用高温气相色谱法测定了一种高黏度聚α烯烃(PAO)的组成。以PAO150为检测对象,采用ASTM D7169方法,确定样品中存在的PAO种类及聚合度,并用色谱等效温度方法求算出聚合度为2~13的聚1-癸烯类化合物的常压沸点。结果表明:PAO150中存在1-癸烯的2~16聚体;当聚1-癸烯的聚合度达13以上时,PAO的沸点比同碳数正构烷烃沸点低100℃以上;高黏度PAO150的釜式蒸馏过程易导致聚合物中的高沸点重组分热裂解,表现为黏度、黏度指数、相对分子质量等降低,溴指数增加。

DETERMINATION OF COMPOSITIONS OF HIGH VISCOSITY POLY ALPHA OLEFINS BY HIGH TEMPERATURE GAS CHROMATOGRAPHY

The compositions of high viscosity PAO150 were determined by high temperature gas chromatography. The types and polymerization degree of PAO were analyzed by ASTM D7169. The atmospheric pressure boiling points of poly α-olefins with the degree of polymerization of 2-13 in the sample were calculated using CET (Chromatography Equivalent Temperature) method. The results indicate that there is a 1-decene polymer with polymerization degree of 2-16 in the sample and the boiling point of 1-decene polymer is 100 ℃ lower than that of paraffin with same carbon number when the polymerization degree is over 13. The high boiling point components in PAO150 are easy to cracking during the kettle-type distillation process, resulting in reduction of viscosity, viscosity index and relative molecular weight, but bromine index.