Preparation And Performance Of Epoxy Functionalized Silicone Resin/nano BaTiO₃ Dielectric Composites

Polymer dielectric composite has become an important material for the preparation of capacitors with good flexibility,high mechanical strength and excellent dielectric properties.In this paper,BaTiO₃ nanoparticles were used as fillers to prepare polymer dielectric composites by ball milling and mixing functionalized BaTiO₃ with epoxy functionalized silicone resin.Because nano-particles are easy to agglomerate,the interaction between nano-particles and the matrix is weakened,which affects the comprehensive properties of dielectric composites.Therefore,it is the focus of this paper to improve the interfacial compatibility of nano-particles and polymers and to obtain dielectric composites with excellent properties by better dispersion of nano-particles in the matrix.At the same time,in order to obtain excellent mechanical and dielectric properties of polymer composites,this paper also added a proper amount of functionalized GO into the composites.The specific research contents and results are as follows:1.BaTiO₃ nanoparticles were in-situ modified with epoxy functionalized silicone resin,then modified BaTiO₃ and epoxy functionalized silicone resin were milled to prepare polymer dielectric composites.The effect of the content of nanometer BaTiO₃on the comprehensive properties of composites was investigated.The results show that the thermal stability of the composites increases with the increase of BaTiO₃content,the modified BaTiO₃ particles are uniformly dispersed in the polymer matrix,and the dielectric properties of the composites are improved.2.Polyurethane?PU?with different molecular weight was synthesized with isocyanate end capped.Then PU was blended with epoxy functionalized silicone resin to prepare PU/EP composite.The properties of the composite were tested,and the optimum addition amount and curing temperature were investigated.The results showed that the polyurethane synthesized by PEG1000 had better thermal properties,the optimum amount of PU was 6wt%and the optimum curing temperature was 80?1 h/120?2 h/150?/2h.Then,BaTiO₃/PU-epoxy functionalized silicone composites with different content of nano-particles were prepared by ball milling and blending the modified nanoparticles with PU/epoxy functionalized silicone composites.The properties of the composites were tested and the dispersion state of nanofiller in polymer matrix was also characterized.The results show that the thermal properties of the polymer composites modified with PU are improved,and the dispersion of the modified BaTiO₃ particles in the matrix is improved.The composites have better dielectric properties.3.Different silane coupling agents were used to modify the surface of graphene oxide?GO?and the modified GO was characterized by IR?TGA?SEM.The results showed that KH560 had the best effect on the modification of GO.Then the modified GO was used as the filler to prepare the GO/BaTiO₃/PU-epoxy functionalized silicone resin composite by ball milling blending method,and the effect of modified GO content on the thermal and dielectric properties of the composite was investigated.The thermal properties of the materials were improved after the addition of GO.