Study On Synthesis And Characterization Of Thermoplastic Polyester Elastomers

Thermoplastic polyester elastomer（TPEE） consists of hard and soft segments,therefore it has high performance with respect to physical and chemical properties.As its application domain becomes more useful,it’s property is studied widely.TPEE was polymerized with DMT,DMI,EG,NPG and TPMG as raw materials in different mixed proportion and in melt polycondensation method.And the structures and properties were investigated by FT-IR,¹H-NMR,DSC,DMA,etc.The results were as follows:1.The absorbtion of funtional groups for C=O(1720 cm^-1),-COO-(1232 cm^-1),C-O-C(1098 cm^-1) showed the main structures by FT-IR.The proportion of NPG and EG in polymer changed with the propotion of NPG and EG by NMR.2.The connected way and order was confirmed by the 2-D NMR such as H-HCOSY,HMBC, DEPT135℃,HSQC.Also the the molar ratio of the sample was figured out.3.The samples were amorphous by XRD;two glass transition temperature for hard segments and soft segments were tested,which showed the microdomain exsited.Tg of the samples increased when the proportion of NPG rose.4.The result of dynamic rheology showed that the melt of TPEE was viscoelasticity liquid. Their melt was microphase separation in the test range and the forms of phase changed with the temperature and the frequency.G′,G″,η′and tanδchanged with the transformation of melt structure in different law.5.The thermal stabilities of TPEE under nitrogen and air atmosphere were tested via thermogravimetry analysis and were compared with different polymer with PTMG.The result of thermodegradation kinetics showed that When studied under nitrogen,all the samples had only one stage,Ti（the initial temperature of decomposition）,Tmax（temperature of max decomposition）, W%（weight of the polymer after the end of a decomposition） decreased when the content of PTMG increased.When studied under air,all the samples had two stages（the second was weak）, and the degradation behavior during the first stage was similar to that under air.The Kissinger and Flynn-Wall-Ozawa methods were used to calculate the decomposition activation energy and the correlative parameter.The decomposition activation energy of TPEE changed with different contents of PTMG by Kissinger while the decomposition activation energy decreased with the increase of PTMG.