Preparation And Application Of High Wear-Resistance Liquid Silicone Rubber

Silicone synthetic leather is the latest man-made functional leather,which has many advantages,such as safety,non-toxicity,physiological inertia,strong stain resistance,good breathability and so on.The main component of silicone synthetic leather is addition-molded liquid silicone rubber,but the main chain of the silicone rubber molecule is Si-O-Si,the oxygen atom in the Si-O bond has no side groups,the length of the Si-O-Si bond is long,and the bond angle is large.The internal rotation is easy,the molecular chain is extremely flexible.The above structure determines that the interaction force between the molecular chains is weak,which leads to poor wear resistance of the silicone synthetic leather.At present,organic silicon synthetic leather is generally reinforced with inorganic filler silica to improve its wear resistance.However,the compatibility between silica and addition liquid silicone rubber is poor,and the reinforcement of silica will make the viscosity of the liquid silicone rubber rise sharply,which makes subsequent processing very difficult.In addition,the effect of silica reinforced liquid silicone rubber needs to be further improved.This paper proposes that MQ and grafted POSS are used to prepare high-strength,wear-resistant silicone synthetic leather,which has poor wear resistance,complex reinforcement process and unsatisfactory reinforcement effect.The thesis is divided into the following two parts:First,based on the principle of similar compatibility,a low surface hydroxyl content vinyl MQ silicone resin with a main chain of Si-O chain was designed and synthesized,and then the vinyl MQ silicone resin was used as a reinforcing agent for silicone synthetic leather.The strong process and reinforcement mechanism are discussed.The research results show that the abrasion resistance of synthetic leather has been greatly improved,and has excellent hydrophobic and antifouling properties;when the M/Q value is 0.8,the addition amount is 22.5%,and the vinyl content is 2.7 wt%MQ silicone resin.At this time,silicone synthetic leather exhibits the best abrasion resistance.In order to further improve the cross-linking density and wear resistance of silicone synthetic leather,a multi-functional reinforcing agent with silsesquioxane(POSS)was prepared by chemical cross-linking,abbreviated as M-POSS-H,to prepare POSS cross-linked nanocomposite silicone synthetic leather.The results showed that the addition of 3%M-POSS-H reduced the amount of wear by 50.1%,increased the tensile strength by 21.0%,and increased the thermal decomposition temperature by 21.0?.The successful preparation of highly wear-resistant liquid silicone rubber material provides a new way for the preparation and application of high-performance silicone synthetic leather.