The Influence Of Inorganic Filler Attapulgite And ZnO On The Flame Retardant And Mechanical Properties Of PA6

PA6 has excellent mechanical strength and chemical stability and is widely used in daily life.However,PA6 has poor impact strength,poor heat resistance and poor dimensional stability,which limits its application.In addition,PA6 is a flammable polymer.The limiting oxygen index(LOI)is only 21%,and the vertical burning test level is only V-2.PA6 has a fast burning speed and generates a lot of black smoke and droplets when burned,which is very likely to cause secondary fire hazards.Therefore,the toughening modification and flame retardant modification of PA6 have important research significance.Based on PA6/PEG elastic modification system and PA6/MCA flame retardant modification system,the flame retardant properties and mechanical properties of PA6 with inorganic filler attapulgite(AT)and zinc oxide(ZnO)were investigated.PA6/PEG block copolymer was prepared by using PA6 prepolymer as hard segment and PEG2000 as soft segment.ZnO particles was added to the block copolymer system to prepare PA6/PEG/ZnO composite with high strength,high toughness and impact resistance.In addition,the nitrogen flame retardant MCA was selected as the flame retardant.The PA6/MCA flame retardant composite was prepared by in-situ polymerization,and AT and ZnO were selected as inorganic fillers in the PA6/MCA flame retardant system to establish synergistic flame retardant.The PA6/MCA/AT and PA6/MCA/ZnO composites were prepared by the agent system.The effects of different compositions of ZnO and AT on the mechanical properties and flame retardancy of the composites were investigated.The structure and properties of the synthesized PA6/MCA/AT,PA6/MCA/ZnO and PA6/PEG/ZnO composites were characterized.The chemical composition of the composites was studied by Fourier transform infrared spectroscopy(FT-IR),and the cross-sectional morphology of the composites was investigated by scanning electron microscopy(SEM).The conditions of melting and cold crystallization of the composites were investigated by differential scanning calorimetry(DSC),and the thermal stability of the composites was investigated by thermogravimetric analysis(TG).The change in crystallinity and the change in crystal state were investigated by X-ray diffractometry(XRD).The fluidity of the composite chain in the molten state was studied by a rotating rheometer.The combustion performance and flame retardant effect were studied by using the limiting oxygen index(LOI)analyzer and vertical combustion.The spline was processed by injection molding and the mechanical properties of the composite were measured by a tensile test.The results show that the thermal stability of PA6/MCA/AT composites is improved.The mechanical properties of PA6/MCA/AT composites reached 44.81 MPa,and the LOI value of the samples reached 27.9%.ZnO particles had good compatibility in PA6/MCA/ZnO composite matrix,which could effectively enhanced the adhesion between phase interfaces and improve the mechanical properties of composites.After adding ZnO,the grain size was smaller and the structure was stable.When the ZnO content was 10%and the MCA content was 9%,the yield stress of the composite reached 40.97Mpa,and the limiting oxygen index of the PA6 composite could be improved to 27.3%.The PA6/MCA/ZnO composite had both excellent flame retardant effect and mechanical tensile properties.By blending ZnO,the thermal stability of PA6/PEG/ZnO composites was improved.The role of the physical intersection to improved the mechanical properties of the composite.The PA6/PEG/ZnO polymer fiber exhibited high elasticity and high modulus fiber properties,and the addition of ZnO improved the mechanical properties of the polymer.