超临界快速膨胀法制备聚乙烯蜡超细颗粒

Preparation of polyethylene wax microparticles by rapid expansion of supercritical solutions

以CO2为溶剂,聚乙烯蜡为溶质,采用超临界溶液快速膨胀法(RESS)制备了聚乙烯蜡超细颗粒。考察了预膨胀温度、预膨胀压力、收集距离等工艺条件对颗粒平均粒径的影响。结果表明,采用较高的预膨胀压力、预膨胀温度有助于获得平均粒径较小的超细粒子;在收集距离50

Using CO2 as solvent and polyethylene wax as solute,the polyethylene wax microparticles were prepared using rapid expansion of supercritical solutions(RESS)method.The influences of pre-expan sion temperature,pre-expansion pressure and collecting distance on the average size of formed fine particles were discussed.It was found that smaller average diameter of fine particles could favorably be obtained under higher pre-expansion pressure and higher pre-expansion temperature.Within the collection distance of 50 mm,the particle size increased with the increase of the collection distance.When the collection distance was more than 50 mm,the particle size did not increase.