Preparation And Properties Of The Cyanate Ester Resin/Core-Shell Polyacrylic/Boron Nitride Composites With High Thermal Conductivity And Toughness

Cyanate ester resin?CE?is a kind of high-performance resin with excellent mechanical properties,adhesive properties,heat resistance,low dielectric constant,and moist heat resistance.It is mainly used in electronic information,copper-clad plate,aerospace,adhesives and other fields.However,due to the inherent structure of CE with a large number of triazine ring structures and aromatic heterocycles after curing,the brittleness of the polymer is relatively high,which limits its application.With the rapid development of cutting-edge industries such as aerospace and electronics industries,the demand for composites is increasing also.Therefore,in order to overcome their shortcomings,many researchers have devoted themselves to researching and improving the toughness and conductivity of CE resins while maintaining their excellent thermal resistance and electrical insulation.In this paper,core-shell structured polymers were used as modifiers to toughen cyanate ester resins,BN as the filler to prepare the composites which has excellent conductivity,thermal stability and electrical insulation properties.Orthogonal experiments were used to determine the factors that affected the toughening effect.poly?n-butyl acrylate?/poly?methyl methacrylate??PBMMA?a core-shell structured modifier,was prepared by semi-continuous seed emulsion polymerization.The function monomer was copolymerized in shell layer to improve the compatibility with the resin matrix.The morphology,particle size and distribution of core-shell toughening agent were characterized by nano-particle size analyzer,TGA,SEM and TEM.Preparation of CE/PBMMA blends materials by melt blending and the optimum core shell modifier was determined by analyzing the mechanical properties,morphologies.The BN particles were initially oxidized in aqua regia solution to yield sufficient hydroxyl groups on BN edge,and then grafting of 3-?2-amino ethyl amino?propyl trioxysilane coupling agent on to hydroxylated BN surface.CE/PBMAM/ABN composites were prepared with a series of different amounts of modified boron nitride.The mechanical and thermal properties,dielectric properties,thermal stability of the composites were investigated.Through the above studies,it was found that the thermal conductivity of composite material was 2.4 times higher than that of the pure resin,and the impact strength and bending strength was 2.8 times and 1.7 times higher than that of the pure cyanate resin when the PBA content of the PBMAM was 60%,grafting functional monomer was acrylamide?AM?,the addition amount of PBMAM and ABN were 5 wt%and 8 wt%,respectively.The thermal decomposition temperature of the composite at the weight loss of50%was 99.9^oC higher than that of the pure cyanic ester.Meanwhile,the volume and surface resistivity of the composites remained 10¹⁵?and 10¹⁵?·cm.The composites with excellent mechanical properties,high thermal stability and thermal conductivity have been successfully prepared and have potential applications in the electronics industry and aerospace industries.