Preparation And Properties Of Flame Retardant Bamboo Charcoal/Polylactic Acid Composites

This project mainly uses bamboo charcoal(BC)as raw material and thermoplastic polylactic acid(PLA)as resin matrix.The continuous preparation of BC/PLA composite material is realized by melt blending and injection molding,which improves the performance of composite material without impairing PLA biodegradability.Expanded graphite(EG)as a synergist and aluminum hypophosphite(AHP)for flame retardant modification of BC/PLA composites,developed a flame retardant BC/PLA that meets economic development and people's needs and has excellent comprehensive performance.The effects of BC and flame retardant addition on the mechanical properties,flame retardancy,thermal stability and crystallization properties of BC/PLA composites were investigated,and the quality ratio was determined.Exploring the pyrolysis and flame retardancy of BC/PLA composites by X-ray diffraction,X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy and surface topography mechanism.The main contents and conclusions of the paper are as follows:(1)Study the effect of BC addition on the performance of BC/PLA composites.When the addition amount of BC is 25%wt,the mechanical properties of the composites are kept at a good level.The excessive addition of BC reduces the mechanical strength and toughness of the composite.The BC accelerates the thermal decomposition of the material,and the thermogravimetric curve moves toward the low temperature section.The addition of BC improves the thermal stability of the material at high temperatures,reduces the glass transition temperature,cold crystallization temperature and melting temperature of the composite,and significantly increases the crystallinity of the material.(2)The new halogen-free flame retardant AHP was introduced into BC/PLA composite to prepare ternary composites.The effect of AHP addition on the properties of BC/PLA composites was studied.The addition of AHP is beneficial to the mechanical properties.And significantly improve the flame retardancy properties of the material.The synergistic effect of BC and AHP reduces the mass loss rate of the composite,increases the thermal stability,significantly increases the char formation,and delays the crystallization process.The addition of AHP effectively reduces the material heat release rate peak(pHRR)and total heat release(THR).And the carbon residue is more dense because of the addition of AHP.(3)Synergistic flame retardant BC/PLA composites were prepared by compounding EG,as flame retardant synergist,and AHP for flame retardant modification The effects of different ratios of AHP-EG synergistic flame retardant system on the properties of BC/PLA composites were investigated.EG is beneficial to the mechanical properties to a certain extent.AHP-EG compounding can significantly improve the flame retardancy of composites and reduce the pHRR and THR.The AHP-EG synergistic flame retardant system combines the advantages of both,which is superior to the flame retardant AHP or EG alone.