Synthesis And Performance Study Of Star-shaped Alkyl Phosphinate Flame Retardant

Intumescent flame retardants(IFR)are efficient in many polymers and are widely used as halogen-free additives owing to their non-toxicity and low smoke releasing.The IFR often experiences an intense expansion and forms protective layers,thus well protecting the underlying material from the action of the heat flux or flame during combustion.This article chooses 2-methyl-2,5-dioxo-1,2-oxaphospholane(OP),star-shaped polyhydric alcohol and metal salt to synthesize a series of star-shaped ester-containing metal salts of alkylphosphinate M(CP).The synthesis process and the products were characterized by FTIR,Thermogravimetric analyses(TGA),X-ray fluorescent spectroscopy(XRF),X Ray Diffraction(XRD),nuclear magnetic resources(1H-NMR and 31P-NMR).M(CP)as a char forming agent and acid source,combining with the blowing agent melamine cyanurate(MC)or melamine polyphosphate(MPOP)were added into(polybutylene terephthalate)PBT and(thermoplastic polyester elastomer)TPEE.The Combustion properties of flame-retarded composites were evaluated by Limit Oxygen Index(LOI),verticle burning test UL-94,TGA,micro combustion calorimeter(MCC)and TG-FTIR were used to investigate the flame retardant mechanism of the materials.The results show that M(CP)shows an excellent char forming ability with the initial decomposition temperature above 350?.M(CP)combining with MC or MPOP can prevent PBT or PTEE from heat flux and dripping during combustion by forming the intumescent layer.SEM-EDX data shows that flame retardants act both in condensed and gas phase.The DSC results shows that melting temperature of the composite materials does not change,but crystallization temperature is increased a little after adding the flame retardant.The mechanical properties decrease with the the amount of flame retardant increasing.The best formula for the PBT/Al(CP)/MC are: PBT:83 wt%,AlCP:13wt %,MC:4 wt%.The best formula for the TPEE/Al(CP)/MPOP are: TPEE:72wt %,Al(PCP):25 wt %,MPOP:3 wt%.In conclusion,M(CP)is an efficient carbon and acid source of a IFR and shows good compatibility with the PBT and TPEE.It is a potential and eco-friendly flame retardant for the polymer.