| Silicone rubber has the following problems in the actual production and applicationprocess. Firstly, air bubbles appear due to curing process, which seriously affects themechanical properties and insulating properties of silicone rubber. Secondly, theviscosity of the base glue becomes large when using silicon dioxide (SiO2) asreinforcing filler for silicone rubber, leading to bad processability. Finally, energyconsumption of the traditional high-temperature curing process is very high.This paper aims to solve the above problems. The main contents and results areshown as follows：(1) The effects of crosslinking agent, catalyst and defoamer on the bubble eliminationand properties of addition type high-temperature vulcanized (HTV) liquid siliconerubber were investigated. The results show that, with increasing the dosage ofcrosslinking agent and catalyst, the curing time of silicone rubber decreases significantly,while the amount of bubble increases. Defoamer can effectively inhibit the formation ofbubble in silicone rubber. The optimal properties of silicone rubber is achieved when theaddition of crosslinking agent, catalyst and defoamer4are0.95phr,1.05phr and0.4phr, respectively.(2) MQ silicone resin and SiO2were used to improve the properties of silicone rubber.The influences of M/Q value, Si-H/Si-Vi value, MQ resin content and SiO2content onthe performances of silicone rubber were studied. The results show that the vulcanizedsilicone rubber possesses the best comprehensive properties when the M/Q value is0.8,Si-H/Si-Vi value is1.6~1.8, vinyl group fraction of MQ resin is3%, MQ resin contentis15%~20%and SiO2content is10%~15%.(3) Liquid silicone rubber can be crosslinked fast by ultraviolet (UV) with the help ofphotocrosslinking initiation system. The results show that the optimal properties ofphotocrosslinked silicone rubber are achieved when the benzophenone (BP) content is3phr, triallyl isocyanurate (TAIC) content is2phr and irradiation time is18s. Moreover,the properties of photocrosslinked silicone rubber are improved gradually withincreasing content of SiO2. |
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