Synthesis And Characterization Of Itaconic Acid Copolyester

The application of polymer materials makes our daily life more comfortable andconvenient. However, it also causes serious environmental problems because they arehard to degrade in nature. Therefore, development of biodegradable polymers will helpto improve the capability and expand its application field. Aliphatic polyesters, withoutstanding biodegradability, became a hot research topic. However, the poormechanical properties and thermal stability as well as relative high cost havedrastically restricted their application. On the contrary, aromatic polyesters haveexcellent thermal stability, good mechanical properties, although they could not bedegraded. Therefore, incorporation of biodegradable aliphatic units into the molecularchain of aromatic polyesters has been regarded as an effective strategy to obtain novelbiodegradable copolyesters. In this article we carried out the synthesis, characterizationand properties study of degradable aliphatic aromatic copolyesters.In this article, a series of biodegradable aliphatic aromaticcopolyesters—poly(butylene terephthalate-co-butylene itaconate)(PBTI) weresynthesized by melt polycondensation from dimethyl itaconate(DI),1,4-butanediol(BD)and dimethyl terephthalate (DMT). The effects of aliphatic/aromatic mole ratio, thekind of catalyst, the content of catalyst, polycondensation time and temperature on thephysical and thermal properties were investigated. The optimal conditions was thataliphatic/aromatic mole ratio was1.2, Ti(OBu)4as catalyst, catalyst content was0.15%(the mole ratio to DI), polycondensation time was3.5h, polycondensation temperaturewas190oC under low air pressure (-0.1MPa).The structure of the copolyesters were studied by means of1H-NMR and FT-IR,DSC, TGA analysis which clearly indicated that the melting temperature,glass-transition temperature and thermal stability were enhanced with the increase ofthe aromatic polyester chain segment. In the third part, one hydrophilic diol(PEG) was selected as copolymerizedcomponent to react with DMT, DI and BD via direct melt polycondensation.We havesynthesized a series of degradable aliphatic-aromatic copolyesters(PBTIG) withdifferent PEG molecular weight and content. Hydrolytic degradation resultsdemonstrated that with the increase of the itaconic acid content, the degradation ratewas faster than before, and adding the hydrophilic PEG significantly increased thedegradation rate of the copolyesters.