Research On Dealcoholized RTV-1 High-strength Low-dielectric Silicone Adhesive

The room temperature curing silicone rubber adhesive has the characteristics of low toxicity,high transparency,chemical inertness,excellent weather resistance,good electrical insulation,and can still maintain good physical and chemical properties in the harsh environment,which is widely used in many fields,such as construction,automobile,electronics,chemical industry,etc.;Among all kinds of room temperature curing silicone rubber adhesives,the room temperature curing one component(RTV-1)silicone rubber adhesive is becoming more and more popular because of its convenient usage,no need of high temperature curing,and innocuity.At present,most of the basic polymers of the room temperature curing silicone rubber adhesive are linear polysiloxane ordered spiral structure,which makes the polysiloxane molecules show non-polarity,low cohesive energy,weak intermolecular force,non-crystallization,and poor physical and mechanical properties after curing.Therefore the silicone rubber adhesives usually need to be reinforced or modified to make it valuable.However,due to the addition of reinforcing fillers,the excellent dielectric properties of the silicone rubber adhesive is destroyed,resulting in the increase of the dielectric constant of the silicone rubber adhesive,which limits its application in microelectronics,aviation and other fields,and further improving the comprehensive performance of RTV-1 silicone rubber adhesive has become a research hotspot.In this paper,the ?-? dihydroxypolydimethylsiloxane is terminated by siloxane containing alkoxy group to make the basic polymer.The effects of catalyst,cross-linking agent,reinforcing resin,reinforcing filler and additive on the silicone rubber adhesive are studied,and the best component and ratio are selected;The tensile strength of the final RTV-1 silicone rubber adhesive is 4.87 MPa,the elongation at break is 118.62%,and the dielectric constant is less than 4;After the hot air aging(200 ?×24 h),the tensile strength is still 3.82 MPa,and the adhesion strength is 2.1 MPa;The characteristic temperature of thermal weight loss greatly increases,and the decomposition temperature rises from 315 ? to 416 ?.Finally,the proportion of each component is optimized,the preparation process is determined,and the dealcoholized one component room temperature curing(RTV-1)silicone rubber adhesive is prepared.The(RTV-1)silicone rubber adhesive has not only excellent mechanical properties,but also good low dielectric properties.After the heat aging,it can still maintain good properties.