Preparation And Properties Of Halogen-free Flame Retardancy And Smoke Suppression Of ABS Composites

ABS resin is a well-known general-purpose synthetic resin.It has the advantages of excellent performance and wide application fields.The demand for it at home and abroad is huge every year.However,the side groups of the ABS resin molecular chain contain a large number of benzene ring groups,which are easy to burn,and will release a large amount of black smoke during the burning process,posing a threat to the safe use of the material.Through preliminary experiments,we found that aluminum diethyl hypophosphite(ADP)has a good flame retardant effect on ABS resin,and can be used as the main component of the flame retardant system in this subject,but it is not conducive to the smoke suppression of the material.In order to comprehensively improve the important indicators such as flame retardant performance,smoke suppression effect,and mechanical properties of ABS resin,we believe that it is necessary to add a synergistic flame retardant to form a flame retardant system.Through the analysis of multiple test results,we found the most suitable one among the three synergistic flame retardants,and determined the formula with the best comprehensive performance as the basic flame retardant and smoke suppression formula.Then,on the basis of this basic formula,continue to complete the further smoke suppression,in-depth exploration of toughening,and coating modification.The main research of this paper is as follows:(1)The flame retardant properties,smoke suppression properties and fire simulation of ABS composites prepared by synergistic flame retardants ammonium polyphosphate(APP),melamine(MA),melamine polyphosphate(MPP)and ADP respectively were studied.According to the test results of environmental conditions,thermogravimetric analysis,mechanical properties,etc.,we found that the comprehensive performance of the composite material under the compound addition of APP and ADP is the best,and when the ratio of APP/ADP/ABS(unit is parts)is 4/16 When /100,its limiting oxygen index can be increased from 18% to 29% of pure ABS,and the smoke density grade can be reduced from86.7 to 68.5 of pure ABS,a decrease of 21%,and the fire safety performance index FPI value can reach 0.215 s/(KW.m-2),still has a high carbon residue rate at 700 ℃,which meets the requirements of flame retardancy,low smoke and fire prevention to a certain extent.Therefore,we confirm that this formula is the basic flame retardant and smoke suppression formula in this research.(2)In the further exploration of smoke suppression,we selected ferrocene,molybdenum trioxide,and zinc borate as smoke suppressants,and found that molybdenum trioxide could significantly improve the smoke suppression effect of the basic formula.On the basis of adding 2 parts of molybdenum trioxide,the smoke density grade of the composite material can be reduced to 57.8.(3)In the exploration of toughening,we selected two toughening agents,ABS high rubber powder and nitrile rubber.It was found that the toughening agent basically had no effect on the flame retardant performance,but the increase of its addition amount would make the material The original smoke suppression effect continued to decline.Nitrile rubber can significantly improve the impact properties of composite materials,and the impact strength can be increased up to 6.8 KJ/m2.(4)Although the main flame retardant ADP has a certain hydrophobic ability,it has poor compatibility with ABS,so we use phenolic resin as the capsule material and ADP as the capsule core,and complete the modification in the form of physical coating.The modified ADP has more efficient flame retardant ability in ABS resin,and the obtained sample has higher bending and tensile properties.