Preparation And Properties Of Polymeric Polyphosphonate Flame Retardant

Polyester is widely used in modern life because of its excellent properties,but polyester is easy to burn and brings great potential safety hazard to people.Therefore,it is very important to study the flame retardant modification of polyester.At present,the flame retardant modification of polyester mainly adopts copolymerization and blending methods.Due to the limitation of copolymerization process on flame retardant monomers and the influence on processing performance,blending is still the most important flame retardant modification method of polyester.The existing blending flame retardants mainly include inorganic and organic flame retardants.Inorganic flame retardant modified polyester has low flame retardant efficiency,poor compatibility and will have a great impact on the physical and mechanical properties of polyester.Therefore,the blending flame retardant modification of polyester mainly adopts organic flame retardants with good compatibility.At present,organic flame retardants for polyester are mainly halogen and phosphorus flame retardants in the market.However,people prefer non-halogen phosphorus flame retardants because of the environmental protection during the use of halogen flame retardants.However,the blending of small molecular phosphorus flame retardant with polyester still cannot avoid the problem of poor compatibility.With the in-depth study of polyester flame retardant,more and more attention has been paid to the development of macromolecular additive flame retardant with good compatibility with polyester and high flame retardant efficiency.Therefore,starting from the synthesis and application of polymer flame retardant for polyester,aiming at the problems of low phosphorus content and poor hydrolysis resistance of conventional flame retardant,based on the heat resistance of DDP,a new type of polymer hydrolysis resistant polyphosphonate flame retardant with fatty acid ester bond was prepared.The main contents are as follows:?1?The effects of antimony triacetate[Sb?CH₃COO?₃],ethylene glycol antimony[Sb₂?EG?₃]and different diols on esterification and condensation kinetics of polyphosphonate flame retardant were studied.The results show that when the catalyst is Sb₂?EG?₃ and the mole ratio of EG/DDP is1.5,the esterification rate K₁₁1 is the largest,the esterification rate X increases with the increase of the mole ratio of EG/DDP,and Sb₂?EG?₃ can obviously improve the polycondensation rate,BDO can better alleviate the steric hindrance effect of DDP,and DDP-BDO has larger esterification rate,esterification rate,polymerization degree and intrinsic viscosity.?2?Nuclear magnetic infrared spectroscopy shows the structure of polyphosphonate flame retardant,and the thermal stability of polyphosphonate is higher.T_5%of polyphosphonate flame retardant in N₂ can reach 406.48?,T_dmaxmax reaches 426.20?,much higher than T_5%?307.5??of DDP.At the same time,DDP-BAO has more aromatic ring structure,and its carbon residue can reach 29.971wt%.Polyphosphonate flame retardant has better hydrolytic stability than DDP,and polyphosphate flame retardant has better thermal oxidation stability.It is kept at 300?for 43min,DDP thermal weight loss is 47%,and the maximum mass loss of polyphosphate flame retardant is29%.?3?The polyphosphate flame-retardant polyester has good hydrolysis resistance and thermal oxidation stability.PET/DDP degrades rapidly when kept at 300?for 10min,while the polyphosphate flame-retardant polyester loses weight slowly with a maximum weight loss rate of18%.SEM and EDX show that polyphosphonate has better compatibility with polyester,and its phosphorus element is uniformly dispersed in polyester matrix.Moreover,the combustion test methods of splines,fibers and films prove that polyphosphonates have good flame retardant effect.