Preparation Of Modified Zinc Sulfide Nanoparticle And Study Of The Flame Retardant And Refractive Properties Of Its Epoxy Resin

Epoxy resin（EP）is widely used in various fields because of its excellent mechanical property,good adhesion and processability.However,the flammability and low refractive index of epoxy resin have greatly limited its application in the optical field.The conventional flame retardant treatment of epoxy resin is often accompanied by the reduction or even disappearance of transparency.Therefore,the preparation of epoxy resin with both good flame retardant,transparent and refractive property has become a current research hotspot.In this study,multifunctional ZnS nanoparticles containing organic functional groups were prepared based on sulfhydryl derivative and ZnS,and then the modified ZnS nanoparticles were introduced into epoxy resin to obtain new epoxy resin nanocomposites with both flame retardant and optical property,and their optical property,thermal stability,flame retardant properties and mechanical properties were systematically investigated.The specific studies are as follows:Functionalized modification of mercaptoethanol（ME）-modified ZnS nanoparticles（MZnS）using diphenylphosphinic chloride（DPPC）.A series of multifunctional ZnS nanoparticles（DPMZnS）were synthesized by controlling the amount of DPPC addition to adjust the phosphorus content on the surface of MZnS nanoparticles,and then DPMZnS/epoxy nanocomposites were obtained.Compared with the pure epoxy resin,the epoxy resin nanocomposite（DPMZnS₂/EP）with 30 wt%of DPMZnS₂ nanoparticles addition exhibited good optical and flame retardant property with only 2.78%reduction in transmittance and refractive index up to 1.635.Its peak heat release rate（PHRR）and total heat release（THR）were reduced by 60.4%and 33.8%.Meanwhile,DPMZnS₂/EP showed good mechanical property,with the tensile strength and impact strength increased by 86.7%and 29.6%,respectively.Modified ZnS nanoparticles containing naphthalene ring（NpMZnS）were synthesized by MZnS nanoparticles and 1-naphthoyl chloride（1-Np Cl）,and then epoxy resin nanocomposites with different NpMZnS nanoparticle addition were prepared.Compared with the pure epoxy resin,the transmittance of 30NpMZnS/EP decreased by 5.86%and the refractive index reached 1.623 when the epoxy resin nanocomposite（30NpMZnS/EP）was added with 30 wt%of NpMZnS nanoparticles.the PHRR and THR of 30NpMZnS/EP decreased by 59.6%and 34.3%,respectively.Meanwhile,the tensile strength and impact strength of 30NpMZnS/EP increased by 20.6%and 59.3%,respectively.The above results indicate that NpMZnS nanoparticles can impart good flame retardant property,refractive property and mechanical property to the epoxy resin.