Preparation Of POSS Containing Phenly Bifunctional Group And Performance Simulation Of Its Composite Material

Silsesquioxane(POSS)is a type of organic-inorganic nano-hybrid unit with a unique cage structure at the molecular level.It has an inorganic framework and adjustable organic functional side chain groups.Therefore,in theory,the dielectric constant of the epoxy resin matrix material can be effectively adjusted,and the thermal and mechanical properties of the matrix material can also be improved.This article explores the corresponding method for synthesizing POSS containing phenyl bifunctional groups,and optimizes its synthesis process to prepare a class of POSS containing amino-phenyl bifunctional groups.Molecular simulation method was used to model and study the cross-linking curing reaction of amino-phenyl POSS modified epoxy resin,and the thermal and mechanical properties of the resulting epoxy resin cross-linked system were simulated and calculated.The synthesis of POSS by hydrolysis condensation method was explored,and the synthesis conditions of epoxy-phenyl POSS with ?-(2,3-epoxypropyloxy)propyltrimethoxysilane(KH560)and oligomeric phenyl POSS were studied.The effect of catalyst on product structure and yield is discussed.Using self-made oligo phenyl POSS and ?-aminopropyltriethoxysilane(KH550)as raw materials,the amino-phenyl bifunctional POSS was prepared by catalytic rearrangement with fluoride ion,and characterize the structure of the synthesized product by infrared spectroscopy and time-of-flight mass spectrometry.When themolar ratio of oligo phenyl POSS and ?-aminopropyltriethoxysilane is 6:1,the product yield can be obtained as 63.66%.Firstly,the structure of the corresponding polymer was constructed and then geometric optimization,annealing and kinetic optimization were completed using computational chemistry software.The cross-linking curing reaction of epoxy resin was achieved using Perl programming language and constantly optimize the experimental conditions according to the results of the cross-linking system.Finally,we determined the degree of the crosslinking system and select the optimal structure to complete the simulation calculation.In order to make a reasonable prediction of the thermal properties,mechanical properties and dielectric properties of the POSS modified epoxy resin cross-linking system,the glass transition temperature,mechanical properties and free volume of the polymer system were analyzed.The results show that the glass transition temperature of the epoxy resin crosslinking system with the content of 25.6% amino-phenyl T8 can be increased by 37.1 K compared with the pure epoxy resin crosslinking system.When the percentage of amino-phenyl T8 is reduced to 14.7%,the glass transition temperature can still be 24.4 K higher than that of the pure epoxy resin system.The addition of amino-phenyl T8 can increase the tensile modulus and shear modulus of the polymer system,but the bulk modulus is reduced to a certain extent.