Preparation And Properties Of Flame Retardant Copolyether-ester

The comonomers of 2-carboxyethyl(phenyl phophinic)acid(CEPPA),and polyethylene glycols(PEG)with different molecule weight and different additive amounts were added during the polymerization process of poly(ethylene terephthalate)(PET)in order to obtain flame retardant copolyether-esters.The intrinsic viscosity,thermal properties,crystallization properties,hygroscopic properties and flame retardancy were characterized and analyzed by Ubbelohde viscometer,differential scanning calorimeter(DSC),thermo gravimetric analyzer(TGA),wide angle X ray diffraction(WAXD),polarizing optical microscope(POM),trace moisture tester,contact angle measurement,limited oxygen index(LOI)and cone calorimeter(CONE).The results of thermal properties tests showed that the thermal transition temperatures of copolyether-esters decreased.The cooling crystallization temperatures(Tcc),melting temperatures and degree of crystallinities(Xc)of modified copolyether-esters increased along with the PEG's molecule weight,while droped with the decrease of their additive amounts.All copolyether-esters' thermal stability showed a slight decrease.The results of crystallization properties tests showed that both of the grain sizes and crystallization rates of copolyether-esters were raised with the increace of PEG's molecule weight and additive amounts.The results of hygroscopic properties tests showed the enhancements of the moisture absorption and hydrophilic properties because of the increace of PEG's molecule weight and additive amounts.The moisture absorption of copolyether-esters which was added with CEPPA and 14%(wt%PTA)PEG1500 was 0.73%,which is 103%higher than PET's 0.36%,and its contact angle was 80.5°,which is 12%lower than PET's 91.5°.The results of flame retardancy tests showed the higher LOIs of copolyether-esters.The LOI of copolyether-esters which was added with CEPPA and 10%(wt%PTA)PEG1500 was 27%.The CONE tests showed the increase of the time of ignition(TTI),time to the peak of heat release rate(tpk-HRR)and time to the peak of mass loss rate(tpk-MLR)of copolyether-esters.There also were some slight decreases of the peak of heat release rate(pk-HRR),the peak of mass loss rate(pk-MLR)and total heat release(THR),which are good for flame retardancy.The smoke suppressions of copolyether-esters performed badly.