Preparation Of Standard Materials With Different Crystallinity Polyethylene

Based on the analysis of the dissolution and crystallization behaviors of polyethylene in solvent via solution DSC, the solution fractionations for HDPE are conducted by stepwise controlling both the temperature and the amount of precipitant. GPC, IR, TGA and POM measurements indicate that the solution fractionation technique can successfully separate all polyethylene samples in accordance with their molecular weight and molecular weight distribution. The crystallinity for HDPE decreases with the increase in its molecular weight under the same experiment condition. The incertitude and uniformity tests on polyethylene fractionation samples containing 30%, 40%, 50%, 60%, 70%, 80% crystallinities via solution fractionation proved that these samples have satisfied the physical and chemical parameters for reference materials of polyethylene.