| Ultra high molecular weight polyethylene(UHMWPE)has high chemical stability,aging resistance and excellent mechanical strength.Its functional composites prepared by bonding with RTV silicone rubber are widely used in various industries due to their excellent properties.However,silicone rubber rubber contains a large amount of C and H elements,which makes the flame retardant effect poor,and it is required to improve its flame retardancy.In order to make silicone rubber have the desired flame retardant effect,predecessors usually add general-purpose flame retardants directly to silicone rubber.However,due to its poor compatibility with silicone rubber and low flame retardant efficiency,it needs to be filled with a large amount of flame retardant.This tends to damage the mechanical properties of silicone rubber.This paper aims to prepare UHMWPE flame retardant and dealcoholized room temperature vulcanized silicone rubber adhesive,synthetic flame retardant plasticizer and the key factors affecting the bonding of UHMWPE and the flame retardancy of silicone rubber were analyzed.The effects of silicone rubber composition and flame retardant on mechanical properties,flame retardancy and the bonding properties were studied.The following three aspects of research work have been carried out:1.The effects of additives such as base glue,filler,cross-linking agent and plasticizer on the silicone rubber itself and the bonding of UHMWPE were investigated.The results showed that when the viscosity of the base rubber was 20000 mm~2/s,100 parts,5 parts of cyclohexylmethoxytrimethoxysilane,2 parts of dibutyl tin dilaurate,10 parts of fumed silica,5parts of the?,?-dihydroxypolydimethylsiloxane plasticizer and 1 part of the KH-570.The prepared silicone rubber adhesive has the best surface dryness and adhesion to UHMWPE.2.Modified hydroxy-terminated polydimethylsilyl plasticizer by melamine formaldehyde resin.Two modified plasticizers with different reaction degrees were synthesized,and the molecular structure of the product was characterized by infrared spectroscopy.TG-DTG analysis showed that the thermal stability of the prepared melamine formaldehyde modified hydroxy-terminated polydimethylsilyl plasticizer was significantly higher than that of the unmodified hydroxy-terminated polydimethylsiloxane.The C-stage polymer polymer-modified hydroxy-terminated polydimethylsilane has the best thermal stability,that is,only 50%at380?.3.Conducted a comparative study on the effects of two modified plasticizers and unmodified plasticizers on the properties of silicone rubber.Including surface drying time,tensile properties,elongation at break,hardness,shear strength to UHMWPE,and flame retardant properties.Explored the relationship between the structure and compatibility of plasticizers and the comprehensive properties of silicone rubber,the melamine formaldehyde B-stage prepolymer modified plasticizer was obtained to optimize the overall performance of RTV silicone rubber.The best experimental results are:the amount of B-stage HSO-MF plasticizer is 7.5 parts by weight,the oxygen index of silicone rubber can reach self-extinguishing performance of 29.1,the surface dry time is 16min,the shear strength is0.195Mpa,the hardness is 45HA,the tensile strength is 1.14 Mpa and the elongation at break is 185%. |
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