The .mwnts / Pet Nanocomposites Preparation And Performance Study

Pure PET,MWNTs-COOH/PET,MWNTs-OH/PET,CEPP/PET,CEPP/MWNTs-COOH/PET nanocomposites have been synthesized via the in situ method.The MWNTs/EG suspensions were analyzed by TEM,and it shows that MWNTs have a good disperse in EG.The structure of nanocomposites was characterized by infrared spectroscopy and TEM.The results of SEM shows that MWNTs have a good distribution in PET.The results of infrared spectroscopy show that the characteristic infrared peaks of MWNTs /PET nanocomposites become indistinct,suggesting that MWNTs have been linked into the macromolecule chains of PET.So it makes MWNTs disperse in PET well.The non-isothermal crystallization behavior of the neat PET and MWNTs/PET composite were investigated by DSC.Two equations were used to analyze the crystallization kinetic data of the samples.The kinetic analysis indicats that modified Avrami equation and Mo equation can successfully describe the crystallization processes of the three samples.The results show that the MWNTs in PET act as effective nucleation agents,and the presence of MWNTs leads to the crystallization of PET molecules at higher temperature and accelerates the nucleation of PET. MWNTs-COOH cause PET crystallize earlier than MWNTs-OH while MWNTs-OH cause PET crystallize faster than MWNTs-COOH.The addition of MWNTs changes the mechanism of nucleation and accelerates the growth of PET crystallization.The thermal degradation behaviors of PET,MWNTs-COOH/PET and MWNTs-OH/PET were examined by TG thermal analyzer.The thermal degradation kinetics were analyzed by Friedman method and Ozawo method.The results show that both the thermal stability of the two types of MWNTs/PET nanocomposites were improved.The thermal stability of MWNTs-COOH/PET nanocomposite is better than that of pure PET through the entire process of degradation.The thermal stability of MWNTs-OH PET nanocomposites was worse than that of pure PET at initial stage of the degradation,but better at late stage.The Combustion Property of pure PET and MWNTs/PET composite were investigated by cone.The results show that the mean heat release rate(HRR) and the mass loss rate(MLR)of MWNTs/PET nanocoposites are all lower than those of pure PET,and MWNTs makes PET flame retardation.The smoke production rate(SPR) and the total smoke production(TSP) of MWNTs/PET nanocoposites are both larger than those of pure PET,and it shows that MWNTs-OH/PET nanocomposites increase smoke production,increasing the fire risk on the contrary.But the production rate and volume content of CO is decreased,and it shows that nanocoposites are much safe.