SiO2/CaCO3复合补强剂对PEMFC垫片材料力学性能的影响

Effects of SiO2/CaCO3 composite reinforcing agents on mechanical properties of gasket material for proton exchange membrane fuel cell

补强剂对质子交换膜燃料电池(PEMFC)垫片材料的力学性能至关重要。选用甲基乙烯基硅橡胶生胶作基础胶,以气相法SiO 2和纳米CaCO 3作复合补强剂制备硅橡胶垫片材料。通过改变补强体系中m(SiO 2)∶m(CaCO 3),研究SiO 2/CaCO 3复合补强剂对PEMFC垫片材料力学性能的影响。实验结果表明:在CaCO 3质量相同且羟基硅油质量随补强剂总质量等比例变化的条件下,随着m(SiO 2)的增加,垫片材料的拉伸强度和硬度升高,但压缩永久变形和压缩应力松弛随之增大;在m(SiO 2)相同且羟基硅油质量随补强剂总质量等比例变化的条件下,随着m(CaCO 3)的增加,垫片材料的拉伸强度和硬度降低,而压缩永久变形和压缩应力松弛随之减小。当m(SiO 2)∶m(CaCO 3)为30∶10时,垫片材料的拉伸强度达到4.93 MPa,压缩永久变形为5.3%(25℃、72 h),压缩应力松弛为7.4%(25℃、24 h),此时垫片材料的拉伸强度、硬度、压缩永久变形和应力松弛等综合力学性能相对较好。

Reinforcing agent is critical to the mechanical properties of gasket material for proton exchange membrane fuel cell(PEMFC).Methyl vinyl silicone rubber was selected as the base rubber,gas phase silica and nano CaCO 3 were selected as composite reinforcing agents to fabricate the silicone rubber gasket material for PEMFC.The various mass ratios of gas phase silica to nano CaCO 3 in the reinforcing system were used to study the effects of SiO 2/CaCO 3 composite reinforcing agents on mechanical properties of gasket material for PEMFC.Results showed that the tensile strength and hardness of the gasket material increased with the increase of SiO 2 mass,under the condition of same CaCO 3 mass and the mass of hydroxyl silicone oil varied with the total mass of reinforcing agent,while the compression set and compression stress relaxation also increased;the tensile strength and hardness of the gasket material decreased with the increase of CaCO 3 mass,under the condition of same SiO 2 mass and the mass of hydroxyl silicone oil varied with the total mass of reinforcing agent,while the compression set and compression stress relaxation also decreased.When the mass ratio of gas phase silica to nano CaCO 3 was 30∶10,the tensile strength of the gasket material was 4.93 MPa,the compression set was 5.3%(25℃、72 h)and the compression stress relaxation was 7.4%(25℃,24 h),the comprehensive properties(i.e.tensile strength,hardness,compression set and compression stress relaxation)of the gasket material were better,compared with those at the other mass ratios of the gas phase silica to nano CaCO 3.