超高分子量聚乙烯热降解行为与冲击性能

THE THERMAL DEGRADATION BEHAVIORS AND IMPACT PROPERTY OF UHMWPE

利用热重分析法 (TG-DTG)、差热分析法 (DTA)、粘度法研究了超高分子量聚乙烯 (UHMWPE)在空气或 N2气氛下的热降解行为 ,考察了 UHMWPE的热降解行为对其冲击性能的影响 ,分析了材料的断口扫描电镜照片。结果表明 ,UHMWPE热降解过程符合自由基连锁反应机理 ,其热降解行为受空气或 N2 气氛、升温速率和恒温时间的影响 ,而热降解导致 UHMWPE微纤断裂是其冲击强度下降的主要原因。

By using of TG DTG, DTA, viscosity method, the thermal degradation behaviors of UHMWPE in air or N 2 are studied. Effet of the thermal degradation on the impact property of UHMWPE is investigated. The notches of samples are analyzed with SEM. The results show that the thermal degradation process of UHMWPE accords with the mechanism of a chain reaction involving free radicals, while the thermal degradation behavior is related to air or N 2 atmosphere, heating rate and heating time at a constant temperature. And thermal degradation resulting in fracture of the microfibers greatly decrease the impact intensity of UHMWPE.