Industrial Formulation Design And Performance Optimization Of Flame Retardant Plexiglass

Polymethyl methacrylate(PMMA),commonly referred to as "acrylic,plexiglass",is a widely used transparent polymer material.However,it has poor heat resistance and is easy to burn,which limits its application range.Existing PMMA flame-retardant methods often sacrifice the heat resistance and transparency of the material itself,so that the material obtains flame-retardant or self-extinguishing properties,even for organic glass with better combustion properties.Although the flame retardant properties are obtained,the original advantages are lost.Therefore,the preparation of plexiglass that has the properties of transparency,flame-retardant and heat resistance is a major challenge in the preparation of flame-retardant plexiglass.This research is mainly divided into two parts.One is to determine the type and amount of flame retardant used in PMMA,and determine the amount of related additives according to the amount of flame retardant.Based on the production conditions provided by the factory and the perspective of maintaining the transparency of plexiglass,we choose to use an additive flame retardant with a refractive index similar to that of MMA,and further study the effect of such flame retardants on the heat resistance and flame retardancy of PMMA.The second is to optimize the material properties for the determined flame retardant system,and discuss the heat resistance of the material after adding isobornyl 2-methyl-2-propenoate(IBOMA),methacrylic acid(MAA),and 2-Hydroxypropyl methacrylate(HPMA),Mechanical performance,transparency and other related performance improvements.Get the following conclusions:(1)Through the discussion of the material synthesis process,the polymerization process of this study is divided into three stages: pre-polymerization,polymerization,and post-treatment.In the pre-polymerization stage,take MMA and 2,2'-Azobisisoheptonitrile(ABVN),stir and heat up to 150 ? and boil for 3-5 min,then lower the temperature to80 ? and keep for 20-30 min to obtain the degree of polymerization At 60-70% of prepolymer.After cooling,add an appropriate amount of transparent stabilizer and stir until the dispersion is uniform to obtain the final prepolymer.In the polymerization stage,take the prepolymer,IBOMA,MMA,HPMA,flame retardant,2,2-Azobis(AIBN)and release agent in a beaker,mix them evenly through mechanical stirring,and then vacuum,then pour it into the prepared silica glass template and polymerize it in a water bath at 62 ? for 10 h.In the post-treatment stage,the plexiglass plate polymerized in the water bath was placed in an oven at 110 ? for polymerization for 3 hours to obtain a flame-retardant organic glass material.(2)In the process of selecting the type of flame retardant,by comparing the flame retardant and heat resistance of the products obtained by adding different flame retardants,the optimal additive flame retardant is determined to be the Chlorinated Alkyl Polyphosphate,and when the addition amount is 36-39 parts(parts by mass),a transparent flame-retardant organic glass plate can be obtained.However,the heat resistance of this flame-retardant board is not good and needs to be further optimized.(3)In the process of adjusting the additive amount,the amount of ABVN is obtained at0.1/10000 of the mass of the methyl methacrylate system.The amount of AIBN is appropriately increased or decreased with the increase of the amount of flame retardant and comonomer.The release agent is also changed from traditional stearic acid to a liquid-solid composite release agent.(4)Through the discussion of material-related performance optimization,the best process conditions is: m(MMA): m(504-L): m(IBOMA): m(MAA): m(HPMA)= 76: 19: 2:1: 2.The addition amount of high temperature initiator is 0.1/10,000 of the total mass,the addition amount of low temperature initiator is 1.8/10,000 of the total mass,and the addition amounts of the two release agents are 1% and 1‰ of the total mass,respectively.(5)The light transmittance and Shore hardness of the product were tested.The light transmittance of the flame-retardant plexiglass plate obtained in this study was 92.6%,and the Shore hardness was 89.17 HD.(6)Through the flame retardant performance and the test of combustion products,it can be known that the oxygen index of the synthetic material in this study is 28%,and the UL94 evaluation level is V-0.This is because the material forms a three-dimensional honeycomb network structure after burning,and a dense carbon layer is formed on the surface of the substrate.Therefore,the effective oxygen and heat insulation layer can prevent the diffusion of combustible gas,delay or even terminate the depolymerization reaction of PMMA,so that the product has good flame retardancy and self-extinguishing.(7)The test shows that the flame-retardant plexiglass panel prepared in this study maintains 90%-92% transparency,its glass transition temperature has also increased from102 ? to 161.9 ?,and the thermal cracking temperature has increased from 175.3? to224.7 ?.