光屏蔽剂与其填充LLDPE耐光老化性能的关系.pdf

塑料助剂
2011年第3期(总第87期
光屏蔽剂与其填充 LLDPE I耐光老化性能的关系
赵文隆张清松『吴智华
(四川大学高分子科学与工程学院)
摘要研究了光屏蔽剂TO2和ZnO填充銭性低密度聚乙烯( LLDPE)体系光老化性能与光反射性
能之间的关系。研究发现,光反射性能较好的TO2与较差的ZnO分别加入LDPE中后,光反射性良好的
TO2有促进 LLDPE老化的现象。通过光在填充材料内部实际通量分析,我们认为这种现象是由于TO2与
ZnO不同程度的光内反射致使紫外光在聚合物中实际通量和光降解作用有羞异的缘故。紫外光在TO2/
PE复合材料中的内反射剧烈,实际通量大,光老化显著,而Zn0对紫外光反射作用较弱,紫外光在ZnO
PE复合材料中的实际通量小,光老化程度小。
关键词光屏蔽剂二氧化钛氧化锌线性低密度聚乙烯光老化
The Relationship between Light Shielding A
gent
and the Resistance to Light Aging of LLDPE Being Filled
Zhao Wenlong Zhang Qingsong Wu Zhihua
College of Polymer Science Engineering, Sichuan University)
Abstract: This paper introduced the relationship between light reflective property and resistance to aging of
nano titanium oxide/linear low density polyethlene (Ti0 LDPE) and nano zine oxide/linear low density
polyethylene(Zno/LLDPE )composites. In this research we found that, after adding Tio2 which has good light re
flective property and Zn which has relatively bad light reflective property into LLDPE separately, Tio the good
light reflection shielding agent accelerated the aging of LLDPE. The reason that the actual ultraviolet light(UV)
flux and photodegradation of Ti02 PE and Zno/PE composites differ from each other is the varying extent of in-
ternal reflection in them. The internal reflection of UV is too severe in TIO2 / PE composite to accelerate the aging
of it. Yet the UV reflection of Zno is relatively weaker, so the actual U flux is low and the resistance to light ag
ing of Zno/PE composite is rather better than the former
Keywords: light shielding agent; titanium oxide; zinc oxide; linear low density polyethylene; light ageing
在光、氧、热等老化因素中,紫外线是聚乙烯
对线性低密度聚乙烯( LLDPE)采用紫外线照
老化的主要因素叫,紫外线所具有的能量会导致高射进行人工加速老化,所选用的光屏蔽剂有TiO2
分子链断键,发生“光化学降解。根据光量子理和Zn0。 LLDPE在经过紫外辐照后,可引起分子链
论,在290~400mm范圃内的紫外光所具有的能量的交联断裂和氧化,从而促使材料老化。通过添
般高于高分子链上各种化学键断裂所需要的能加不同光屏蔽剂,测定紫外光照射前后LDPE的
量,而且,远紫外光(波长200-300nm)的存在还会拉伸性能,同时测定不同光屏蔽剂加人后材料对
使聚乙烯的老化过程更加明显。
紫外光的反射率,得出加入不同反射率的光稳定
剂与材料老化程度的关系,探讨不同反射率对
收稿日期:2011-04-07
LLDPE耐老化性能的影响。实验中,采用断裂伸长