Effects of Silicone Grease on Silicone Rubber in Physical Characteristics

Abstract

For the purpose of sealing and convenient installation, silicone grease is coated where cable and cable accessory engage. However, grease can cause swelling of silicone rubber, affecting the physical characteristics of silicone rubber. This paper researched on the swelling behavior of silicone rubber caused by silicone grease under different tensile deformations with measuring the mass, volume, density, hardness, tensile strength at break, elongation at break and elastic modulus during swelling process. The four test groups of unswelling & untensile, swelling & untensile, swelling & tensile-20%, swelling & tensile-40% had been set, and the parameters were measured every 24 hours during the swelling of the silicone rubber coated with silicone grease. Significant increase in the mass and volume had took place during the swelling process, which indicated that silicone grease could cause serious swelling of silicone rubber. While silicone rubber was in the state of stretched, the quantity and sizes of pores both increase, leading to a severer state of swelling. What’s more, significant decrease in the hardness, tensile strength at break and elongation at break had been observed from the measurements during the swelling process, indicating the deterioration of physical characteristics, which would have effects on the insulation condition of the interface of SiR/XLPE.