Preparation Of Epoxy Intumescent Flame-Retardant Coating And Study On Its Flame-Retardant Performance

Epoxy resin(EP)is a widely used thermosetting resin.It has the characteristics of corrosion resistance,strong adhesion,acid and alkali resistance,and excellent mechanical properties.It is widely used in electrical engineering and electronics,machinery manufacturing,aerospace,industry,steel structure construction and other fields.However,EP's limiting oxygen index(LOI)is only 19%,which is a flammable material with poor thermal stability and will release a lot of heat and smoke during the combustion process,posing a threat to the safety of life and property.These factors limit the application of EP,so it is necessary to carry out flame retardant research on EP.In this article,by adding intumescent flame retardants(IFR),organic montmorillonite(OMMT),chicken egg shells(CSE),aluminum diethyl phosphinate(ADP)and melamine phenyl phosphonate(MPP)to EP,epoxy intumescent flameretardant coatings of different components were prepared.Cone calorimeter,limiting oxygen index analyzer,thermogravimetric analyzer,scanning electron microscope,etc.characterize the properties of materials.The main research results are as follows:(1)The synthesized OMMT and IFR are used as flame retardant to prepare OMMT/IFR epoxy intumescent flame-retardant coating.The research results show that when the OMMT content is 0.7 wt%,the pHRR and TSP are lowered by 35.2% and18.3%,respectively,compared with those without OMMT,and can synergistically form a dense and thick char layer with IFR When the OMMT content is 1.3 wt%,the THR is reduced by 15.2% compared with OMMT is not added.It shows that OMMT/IFR can reduce heat release and smoke generation and improve flame-retardant performance when it is flame retardant.(2)CES and IFR are used as flame retardant to prepare CES/IFR epoxy intumescent flame-retardant coating.The results of the study showed that when the CES content is2.6 wt%,the pHRR and THR are reduced by 40.1% and 22.9%,respectively,compared with CES is not added.The introduction of CES can promote the formation of a dense and smooth char layer and effectively reduce heat transfer.When the CES content is 4.0wt%,the TSP of the sample is reduced by 33.7% compared with CES is not added.Adding CES/IFR can improve the flame-retardant properties of flame-retardant coating and reduce heat release and smoke generation.(3)Use ADP alone as a flame retardant and compound ADP with MEL or PER to prepare ADP/MEL/PER epoxy intumescent flame-retardant coating.Increasing ADP content can increase the LOI of the flame-retardant coating.When the ADP content is15 wt%,the LOI reaches 29.5%,and the pHRR is 47.6% lower than that of non-flame retardant EP.When ADP is compounded with PER,the pHRR,THR,and TSP are reduced by 7.0%,10.0%,and 13.2%,respectively,compared with the ADP content of10 wt%,and a dense and thick char layer can be seen in the SEM.When ADP and PER are compounded,it can improve the char-forming ability of the flame-retardant coating.(4)The synthesized MPP and PER are used to prepare MPP/PER epoxy intumescent flame-retardant coating.When MPP is used alone,the LOI of EP will not be significantly improved.After MPP and PER are combined,it can pass the V-0 level test.The experimental data of the cone calorimeter showed that when MPP and PER are compounded,the pHRR?THR and TSP of the sample are reduced by 11.8%,9.6% and7.1%,respectively,compared with the MPP alone,and a dense and continuous char layer is formed.The combination of MPP and PER can reduce the heat release of the coating,inhibit the escape of smoke,and improve the flame-retardant performance.