Research On Low Dielectric Properties Of Epoxy Resin Modified By Styrene Copolymer

With the rapid development of electronic information technology，it havehigher requirements for the performance of printed circuit board（PCB）.Epoxy resinis still the main Copper Clad Laminate matrix resin using on a significant scale forits excellent overall performance and low cost.At present it cannot satisfyapplication requirements completely of electronics for its high dielectric constantand dielectric loss.So we need to reduce the dielectric constant and dielectric loss,also improve its heat resistance by means of modifying for epoxy resin.Styrene can reduce the dielectric constant of polymers because of its nonpolarproperty; Maleic anhydride provides anhydride groups, which can promote thecuring of the resin；N-Phenylmaleimide can improve the heat resistance of the resinfor Maleimide groups. The purpose of this paper is synthesizing of terpolymer(SMN) as epoxy resin modifier of low dielectric and heat-resistant，which havepolymerized by styrene-maleic anhydride-N-phenylmaleimide.In this paper, styrene, maleic anhydride and N-phenylmaleimide are used asmonomers with dibenzoyl peroxide as initiator. Meanwhile, It have changed theratios of the three monomers and the amount of chain transfer agent. We finally get aseries of terpolymer SMN by solution polymerization. The structure of SMNmonomer was studied by FTIR. The molecular weight and its distribution wasinvestigated by GPC.The SMN with different styrene content and molecular weight of Different uselevel mix with Methyl tetrahydro phthalic anhydride （MeTHPA）. Being curingagent of epoxy resin，have SMN into epoxy resin chain segments. The curingreaction of EP/SMN/MeTHPA system was studied by FTIR. There have researchedmechanical properties, thermal properties and electrical properties of modifiedsystem by Microcomputer control electronic universal testing machine,HTD,TGA，DMA and Precision impedance instrument. It turned out that after being modified bySMN，the system not only keep mechanical properties basic stable，but also improveheat resistance and dielectric properties of the cured product. When the molar ratio of styrene, maleic anhydride, N-phenyl maleimide was4:1:1，chain transfer agentand BPO was1:3，and dosage of the modifying agent is10phr. In frequency range of1~30MHz, the dielectric constant of the cured product is3.28~2.82, the dielectricloss is3.11×10-3~3.35×10-3.The heat distortion temperature is132℃, a glasstransition temperature is136℃,5%weight loss temperature (T5%) is363℃, thetensile strength is55MPa, the flexural strength is98MPa. The cured product of themodified have displayed excellent overall performance.