Nano-material Modified Silicone Pressure Sensitive Adhesive And Developed Of Composite Materials

Silicone pressure sensitive adhesive is often used as class H insulation materials.With its unceasing development, electrical and electronic equipment gradually hasthe characteristic of light weight, high power, good reliability, long service life andlow energy consumption, which put forward higher requirements for the heat-resistant and dielectric properties of insulating materials.Traditionally we adopted a method to enhance high chain to rigid, to makepolymer crystallization or cross-linked, to reinforce polymer internal bonding forceand to improve heat resistance, however, this method reduces polymer toughness. Incontrast, with the help of nanotechnolo, silicone pressure sensitive adhesivemodification can be reached due to its small particle size, great specific surface area,high surface energy, and the great interface function generated between the greatinterface function in polymer modification of its components which gives some newproperties of materials.This paper adopts the nano-SiO₂, nano-Al₂O₃and montmorillonite （MMT） tomodify silicone pressure sensitive adhesive. The nano powders modified by silanecoupling agent and intercalation agent under ultrasonic is evenly dispersed into thesilicone pressure sensitive adhesive; mica paper with the modified adhesive thenreinforced with electrician alkali-free glass cloth and polyimide film for double-sidedof flexible composite material. We studied the effect of different surface treatmentmethods on the nanometer powder dispersion and analyzed the effect of threenanometer powder admixture on thermal stability of silicone pressure sensitiveadhesive and dielectric properties of composite.The results showed that: when the content is less than3wt%, these three kindsof powder raised the pressure sensitive adhesive initial decomposition temperature, atthe same time slowing down the weight loss rate. Thermal stability relative order ofthe modified material is: content of1wt%OMMT modified silicone pressure sensitive adhesive> content of1.5wt%nano-Al₂O₃modified silicone pressuresensitive adhesive> content of3wt%nano-SiO₂silicone pressure sensitive adhesive.Breakdown strength of flexible composite material shows an upward trend withincreases of nano powder content, its order is: content of OMMT1wt%composite>content of nano-SiO₂1.5wt%composite> content of nano-Al₂O₃1.5wt%composites.Volume resistivity decreases slightly with the joining of nanometer SiO₂and Al₂O₃while greatly increased when MMT was added to composite. The volume resistivityof composite reached to62.38×10¹²O·m when the OMMT content is1wt%.