紫外吸收剂对硅橡胶力学和表面性能的影响研究

Study on UV Absorber Effect on the Mechanical and Surface Properties of Silicone Rubber

硅橡胶在使用过程中易受紫外辐照作用发生老化,从而影响表面结构和性能。在硅橡胶中加入3种紫外线吸收剂UV-327、UV-531及UVP-788,研究了不同种类及不同用量的紫外吸收剂对硅橡胶及其老化过程的力学性能及表面自由能的影响。结果表明:加入紫外吸收剂对硅橡胶样品的拉伸强度、断裂伸长率及邵氏硬度具有较大的影响,其中加入1份紫外吸收剂的硅橡胶的综合力学性能较好;在紫外辐照720h后,未添加紫外吸收剂的硅橡胶表面自由能由原来的20.7mJ/m^2激增到67.0mJ/m^2,其中酸性分量γ+s和碱性分量γ-s均大幅度增加,而加入1份紫外吸收剂的硅橡胶的表面自由能只有小幅度增加,其中加入UV-327和UV-531具有较好的效果。

The silicone rubber with low surface free energy is easy to be damaged by UV irradiation, which will affect its surface structure and properties. Three kinds of ultraviolet absorbent of UV-327, UV-531 and UVP 788 were added into silicone rubber, and the effects of types and dosage of ultraviolet absorbents on the mechanical properties and surface free energy of the silicone rubber were investigated systematically. The experimental results show that the addition of ul- traviolet absorbent has great influence on tensile strength, elongation rate and hardness of the silicone rubber sample. It was found that the comprehensive mechanical properties of the silicone rubber with 1 phr UV absorbent are better. After 720 h UV irradiation, the surface free energy of silicone rubber without UV absorber increases from 20. 7 mJ/m2 to 67 mJ/m2 , and the acid component γs＋ and alkaline component γs- both increases sharply, but the surface free energy of silicone rubber with I phr UV 327 or UV 531 only increases a little.