低γ-辐照剂量下聚丙烯的交联与性能研究

Crosslinking and Properties of γ-Irradiated Polypropylene under Lower Dose Irradiation

考察了在空气气氛下 ,敏化剂和辐照剂量D对PP的交联程度、力学性能和热性能的影响。结果表明 :在空气气氛中 ,所研究的PP的初始凝胶化剂量Dg 约为 0 .3kGy。当D≈ 1.0kGy时 ,PP 1(不含敏化剂 )的交联程度最大 ;当D≈ 2 .0kGy时 ,PP 2 (含敏化剂 )的交联程度最大 ,且适当的敏化剂能较大幅度地提高PP的交联程度。不含敏化剂的PP的力学性能和热性能受D的影响较小 ;然而 ,加入适当的敏化剂对提高γ -辐照PP的强度、刚度和结晶温度Tc 均有利 ,但使PP的韧性 (如断裂伸长率 )和加工流动性大幅度下降。

The effect of radiation dose D and multi functional sensitizer on crosslinking degree, mechanical properties and thermal performance γ irradiated polypropylene(PP) under low dose irradiation and air condition was investigated.The results show that D g,the doses for incipient gel formation, of the PP was about 0.3 kGy; the maximum of crosslinking degree of irradiated PP was realized when D was close to 1.0 kGy (without sensitizer) and 2.0 kGy (contianed sensitizer) in air respectively; proper sensitizer could improve the crosslinking degree of irradiated PP greatly. PP irradiated at low doses in air was endowed with mechanical properties and thermal performance almost similar to those of the unirradiated one. However, its tensile strength and Young's modulus could be increased. Crystallization occurred at higher temperature. But its elongation and melt flow rate decreased sharply with the addtion of the sensitizer into PP.