Preparation Of Bamboo Fiber-based Flame Retardant Polypropylene Composites:Flame Retardancy And Thermal Property

Polypropylene(PP)is widely used in building materials,automotive interiors,furniture and electrical appliances because of its excellent mechanical properties,good processability and chemical resistance.However,PP has extremely high flammability,and there is melting dripping phenomenon in the combustion process,which has serious potential fire hazards,which limits the application of PP.To solve this problem,two methods of preparing environment-friendly flame retardant PP composites based on modified bamboo fiber(BF)are proposed in this paper.The specific research contents are as follows:Melamine-formaldehyde resin encapsulated BF(MFBF)was prepared by microencapsulation technology and the flame retardant system was constructed with microencapsulated ammonium polyphosphate(MFAPP),on the basis of which environmentally friendly flame retardant PP composites were prepared.Flame retardant tests showed that pure PP was unrated in the UL-94 test and the limiting oxygen index(LOI)was only 18.5%.When 50wt%MFBF and 20wt%MFAPP were added,the flame retardant properties of the PP composites were significantly improved,with the LOI increasing to 25.5%and the UL-94 reaching a V-0 rating,and the immersion test results found that the UL-94 test was still a V-0 rating after 36 hours of immersion at 70℃.The CCT test results showed that the peak heat release rate of the PP composites(pHRR)and total smoke release rate(TSR)of 344.3kW/m2 and 922.0m2/m2 respectively,a reduction of 66.0%and 36.5%respectively compared to pure PP.XPS and SEM test results show that the presence of Si-O-C and Si-P structures in the residual char of the PP composite contributes to the formation of a high quality char layer that can effectively block combustible gases and heat and protection of the bottom matrix.The flame retardant modification of BF with biomass phytic acid(PA)was used to prepare the all-biomass flame retardant PABF and blended with silica gel-coated APP(MCAPP)to prepare flame retardant PP composites.test results showed that when 56.7wt%PABF and 10wt%MCAPP were added compared to pure PP,the LOI of PP composites improved from 18.5%to TG test results show that at high temperatures,pure PP has almost no carbon residue and PP composites have an improved carbon residue of 15.8%.CCT test results show a 63.7%decrease in pHRR and a 45.9%decrease in total heat release(THR)for PP composites compared to pure PP.The TGIR test results revealed that the presence of phosphorus containing compounds was observed in the PP composite pyrolysis products,which could achieve the effect of inhibiting combustion chain reactions by trapping OH and H radicals in the gas phase.Figure[22]Table[7]Reference[96]...