聚乙烯由于耐溶剂性较好,一般只能在较高的温度下,溶于少数溶剂中,如对二甲苯,四氫萘,十氫萘和α-氯代萘等。对低压聚乙烯来说,更由于它的结晶度高,溶解温度相应地必须提高到125℃以上。因此无论作分子量的测定或者分级实验,操作上都增加了不少困难。例如粘度测定除了需对粘度计作适当设计外,还必须考虑氧对聚乙烯的降解作用。渗透压测定 Due to the better solvent resistance, polyethylene can only be dissolved in a few solvents such as paraxylene, tetralin, decalin and α-chloronaphthalene at higher temperature. For low-pressure polyethylene, and because of its high crystallinity, the dissolution temperature must correspondingly be raised above 125 ° C. Therefore, both for the determination of molecular weight or grading experiments, operations have increased a lot of difficulties. For example, viscosity measurement in addition to the appropriate design for the viscometer, but also must consider the degradation of oxygen on polyethylene. Osmotic pressure measurement