Effect of type and proportion of structure control agents on properties of silicone rubber

Abstract

The heat curing silicone rubber was prepared with methyl vinyl silicone rubber as raw rubber and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane as curing agent by the additon of silica and structural control agents via two-stage vulcanization.The effects of the type and combined proportion of structure control agents on the mechanical properties and heat resistance of heat curing silicone rubber were studied.The results showed that the addition of hydroxymethyl phenyl silicone oil (OH-PMPS) could greatly improve the hardness, tear strength, rebound resilience and heat resistance of silicone rubber, but when the amount of OH-PMPS was too large, the tensile strength of silicone rubber would decrease.However, hexamethyldisilazane (HMDS) and hydroxyl silicone oil (OH-PDMS) could improve the tensile strength and elongation at break of the materials, respectively.When the amount of HMDS was 4 phr and the amount of OH-PDMS and OH-PMPS was both 2 phr, the comprehensive performance of silicone rubber was better.

Keywords

• silicone rubber
• structure control agent
• mechanical property
• heat resistance