Synthesis And Application Of N-substituted Maleimide Heat-resistant Modifier

In recent years,due to the rapid expansion of the use of plastic materials,the people have put more and more stringent requirements on the performance of fine polymer materials,especially the heat resistance of materials.In this paper,using the characteristics of the heat-resistant main monomer N-cyclohexylmaleimide?CHMI?,CHMI is used as a heat-resistant monomer in the copolymer heat-resistant modifier to improve its heat resistance,and some remarkable results have been achieved.The specific research contents are as follows:?1?The terpolymer CHMI-St-GMA was prepared by means of N-Cyclohexyl maleimide?CHMIN?,styrene?St?,glycidyl methacrylate?GMA?,the initiator benzoyl peroxide?BPO?and solvent xylene as raw materials.The effects of different monomer content on the solvent resistance,glass transition temperature?Tg?,molecular weight and its distribution of heat-resistant modifiers were investigated.The optimum synthesis conditions showed that:the polymerization monomer and 0.6%BPO are reacted at 105?.for 4 hours to obtain a heat-resistant modifier CHMI-St-GMA having a Tg of about 200?.,a maximum molecular weight of 69000,and a distribution between 1.8-2.3.At the same time,it has good solvent resistance.?2?The thermal degradation kinetics of glycidyl methacrylate?GMA?copolymer heat-resistant modifier under different heating rates was investigated by thermogravimetry.Using Kissinger,FWO and Friedman's three different methods to explore their thermal stability,the kinetic constants and the apparent activation energy were calculated,which was based on the Arrhenius equation k=k exp?-E?RT?.The results showed that:With the increase of the heating rate,the thermal degradation temperature and the thermal degradation rate of the GMA polymer are all increased.The DTG peak is high and the peak temperature moves to the high temperature region;the degradation activation energy?E_a?of CHGS was 224.511kJ/mol and the pre-exponential factor A was 2.558×10¹³ by Kissinger method.The results of FWO and Friedman were basically the same.E_a was221.4613kJ/mol,and the reaction order was 1.1107..?3?At the same time,using a batch polymerization method,the polymer structure was used to control the synthesis of the quaternary polymer heat-resistant modifier CHMI-MMA-St-?-MeSt,and the heat-resistance modifier thermogravimetry of different raw material ratios was investigated,glass transition temperature,molecular weight and its distribution.The results show that by replacing part of styrene with?-methyl styrene,the ratio of different raw materials has a certain influence on the reaction system conditions,and adjusts with the change of CHMI to St ratio,but the process conditions do not change significantly;The initial thermal decomposition temperature of CHMI-MMA-St-?-MeSt is above 200?.With the increase of the percentage of CHMI monomer,the initial thermal decomposition temperature also increases,and the maximum decomposition rate can reach400?.