Research On Preparation And Properties Of Heat-resistant Elastomer For Seal Of Bottle Soymilk

According to the work requirements of gasket of bottle soymilk, SBS,EPDM andsilicone rubber are chosen as the raw materials, and compressibility, resilience, thecompression permanent set at high temperature, curing characteristic, hardness and thecompression stress-strain are taken as the evaluation indexes. SBS heat-resistant elastomerand EPDM/silicone rubber blending elastomer are prepared by crosslink and blend. Themainly research works are summarized as follows:(1) Research on preparation and properties of SBS heat-resistant elastomerDCP is taken as the curing agent of SBS, and naphthenic oil is taken as the filling oil ofSBS. The effects of DCP and naphthenic oil on the SBS properties are respectively researched.The results show that: When SBS includes0.5or1.0portion DCP, mass ratio of SBS/naphthenic oil equals7.5:2.5, the comprehensive properties are the best. When thedeformation of gasket made by the SBS heat-resistant elastomer (mass ratio of SBS/naphthenic oil equals7.5:2.5,0.5,1.0portion DCP) in the initial seal is between7.03%and8.93%（0.5portion DCP）, between5.14and6.80%（1.0portion DCP） respectively，thegasket could exhaust steam at126℃, and the seal force of gasket is between0.4MPa and0.6MPa at26℃.(2) Research on preparation and properties of SBS/EPDM blending heat-resistant elastomerThe effects of the blend ratio of SBS/EPDM on the properties of SBS/EPDM blends areresearched. The results show that: it’s difficult to balance compressibility, resilience and thecompression permanent set at high temperature of the SBS/EPDM blends of different blendratios. So, the blends are not applicable for gasket of bottle soymilk.(3) Research on preparation and properties of SBS/EPDM blending heat-resistant elastomerThe effects of the blend ratio of EPDM/silicone rubber, curing agent, post vulcanizationconditions on the properties of EPDM/silicone rubber blends are researched. The results showthat: When the blends include1.0portion DCP, mass ratio of EPDM/silicone rubber=7:3, postvulcanization condition is170℃×1h, the comprehensive properties are the best. But thegasket made by the EPDM/silicone rubber blending heat-resistant elastomer (mass ratio ofEPDM/silicone rubber=7:3,1.0portion DCP, post vulcanization condition is170℃×1h) can’tmeet the sealing force demands in the process of thermal sterilization and storage seal at thesame time, it’s not applicable for gasket of bottle soymilk.Compared with the others, SBS heat-resistant elastomer can meets the actual needs， which is the most suitable elastomer as gasket material of bottle soymilk.