Study On The Modification Of PP And PET By Poiyphosphatet Flame Retardant

With the increasing demand for flame retardancy of materials in the market,the research of flame retardant polypropylene(PP)has become a hot topic and is widely applied in various fields.In this paper,Poly(6-oxido-6H-dibenzo[c,e][1,2] oxa-phosphinin-6-yl phenyl phenylphosphate)(POPP)and poly(biphenyl phenoxy phosphate)(PBPP)with good char-forming performance were synthesized by addition reaction between 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-xa-10-phosphaphenanthrene-10-oxi-de(ODOPB),4,4'-Dihydroxybiphenyl and phenyl dichlorophosphate(PDCP)as raw materials.These two novel polyphosphate flame retardants compounded with ammonium polyphosphate(APP)at the mass ratio of 1:2 were added into PP to form a series of PP/FRs and the performance were evaluated.Flame retardant polyethylene terephthalate(PET)is widely used in the fields of engineering plastics and fibers.In general,halogen-free flame retardants are added,which the polyphosphate ester flame retardants have attracted much attention in recent years because of its high efficiency,high molecular weight,low smoke and no toxicity.Two novel polyphosphate ester flame retardants(POPP and PBPP)were prepared by a simple polymerization reaction at the early stage,and they were applied to PET by different compound systems with APP and montmorillonite(MMT).The specific research contents and test results are as follows:(1)Two kinds of polyphosphate flame retardants,POPP and PBPP,were synthesized by melting method.Their structure and thermal propertie were analyzed.The results show that the two flame retardants have two thermal decomposition stages and have good char formation performance.The residual carbon content of POPP at 700°C is 36.39 %,while that of PBPP is up to 51.84 %.(2)POPP and PBPP were used as carbon agents compounded with APP to form the different FRs were added into PP and PET.In order to study the influence of the ratio of POPP,PBPP and APP on the flame retardance of PP and PET,The results showed that the flame retardance in the different systems of PP and PET was optimal when the ratio of POPP/PBPP and APP was 1:2.(3)POPP/APP and PBPP/APP were applied to flame-retardant PP,The Flame retarding performances,thermal stability and residual carbon morphology of modified PP composites were investigated by limiting oxygen index(LOI),vertical burning test,thermo gravimetric-differential thermal analysis(TGA-DTA),cone calorimetry(CONE)and scanning electron microscope(SEM).The results reveal that for the PP systems,POPP/APP had better flame retardant perfoemance than PBPP/APP at the same dosage.(4)POPP,PBPP and MMT,APP were composed of different flame retardant systems-POPP/MMT,POPP/APP,POPP/APP/MMT(PBPP is the same as this ratio)were added to the PET separately and theirs Perform performance were tested.The results showed that when combined with APP alone,PBPP/APP-PET exhibited excellent flame retardant performance,We also can see that the thermal stability and char formation performance of PBPP/APP-PET systems are better from thermo gravimetric analysis.Comparison between the two systems,the HRR,EHC,and THR of PBPP/APP-PET decreased more significantly.The POPP/MMT-PET system has better flame retardant performance when combined with MMT alone.After adding 1 % of MMT on the basis of the two systems and APP compounding,they not only improved the flame retardant properties and residual carbon content of the material,but also reduced the amount of flame retardant added,and showed a good effect of suppressing smoke,Save costs.