Synthesis Of Epoxy POSS And Modification Of Epoxy Resin

Polyhedral Oligomeric Silsesquioxane(POSS)is an organic/inorganic nano-hybrid material that can be incorporated into various polymers by physical blending or chemical crosslinking,and has good compatibility with polymers.POSS can achieve true molecular-level compounding with polymers,which can significantly improve the mechanical strength,thermal stability,flame retardancy,oxidation resistance and anti-aging properties of polymers.In this paper,octavinyl POSS was first synthesized,and then epoxidized to octavinyl POSS to obtain epoxy POSS.The mechanical strength of the epoxy resin modified by epoxy POSS was used.In this paper,octavinyl POSS was synthesized by hydrolysis condensation method.The effects of silane coupling agent monomer,solvent type,catalyst hydrochloric acid concentration,reaction time and reaction temperature on the synthesis were studied.The structure and purity of octavinyl POSS were tested by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance spectroscopy and hydrogen spectroscopy(NMR),mass spectrometry,liquid chromatography and powder X-ray diffraction(XRD).The experimental results show that the best synthesis process is that the silane coupling agent monomer is vinyltrimethoxysilane,the solvent is acetone,the catalyst hydrochloric acid concentration is 6 mol/L,the reaction time is 48 h,and the reaction temperature is 40 °C.octavinyl POSS material.The optimal process method was used to carry out a 20-fold scale-up of the laboratory amplification,and the optimum process conditions were verified to be suitable for mass production.Epoxy POSS was prepared from octavinyl POSS.The octavinyl POSS was epoxidized using m-chloroperoxybenzoic acid and indirectly synthesized peracetic acid as oxidant,and the product was subjected to Fourier transform infrared spectroscopy(FT-IR),mass spectrometry,liquid chromatography and other testing methods,determined that m-chloroperoxybenzoic acid as an oxidant,dichloromethane as a solvent can better control the degree of epoxidation,can be obtained in the cage eight apex angles all epoxidized Epoxy POSS.The epoxy epoxide with the highest degree of epoxidation was prepared and compounded with E-51 resin.The epoxy POSS/resin composites were analyzed by Fourier transform infrared spectroscopy to show that the epoxy POSS chemically reacted with the epoxy resin system to form a crosslinked network structure.SEM-EDS elemental analysis showed that the epoxy POSS was more evenly distributed in the epoxy resin.The mechanical properties of epoxy POSS/epoxy composites at room temperature,150 °C and 200 °C showed that the flexural properties and tensile properties of the composites were the best when the epoxy POSS was added at 4%.The flexural strength of epoxy resin modified at room temperature,150 °C and 200 °C is 148.9 MPa,12.4 MPa and 6.7 MPa,which is 42.1%,181.8% and 272.2% higher than that of pure epoxy resin respectively;The tensile strength at room temperature was increased by 5.2%,respectively.