Synthesis And Characterization Of Aliphatic Polyesters Of Methyl Succinic Acid

The application of polymer materials made our daily life more comfortable andconvenient. However, it also causes serious environmental problems because they arehard to degrade in nature. Therefore, it is important to develop biodegradable polymers.Aliphatic polyesters, with outstanding biodegradability, bioabsorbability andbiocompatibility, have attracted great interest of researchers in recent few decades. Inthis paper, the aliphatic polyester using biomass chemical product, itaconic acid, as rawmaterials, was prepared. Then, polycondensation mechanism of the polyester wasresearched, and regulation mechanism of molecular weight and structure of the polyesterin the esterification and polycondensation process was obtained. Furthermore, structureproperties of the polyester was improved by copolymerization.In detail, the methyl succinic acid was prepared using direct hydrogenation methodwith itaconic acid as raw material and catalyzed by Nickel. The conditions ofhydrogenation process, including reaction time, reaction temperature, amount of catalyst,solvent and other factors were discussed respectively. It was showed that the conversionrate of itaconic acid was over99%when the reaction was carried out at50℃for60minutes using methanol as solvent. There was no obvious changes observed in catalyticactivity during recycle use. Fourier transform infrared spectroscopy (FT-IR) and nuclearmagnetic resonance hydrogen spectrum (1H-NMR) showed that the product wasmethylsuccinc acid with high purity. Poly(butylene methylsuccinate)(PBM) was synthesized with methylsuccinc acid and1,4-butanediol as raw materials catalyzed bytetrabutyl titanate. The influencing factors of esterification and polycondensation onsynthesis of the polyester were studied. The results showed that when the esterificationtemperature was170℃, the molar ratio of BD and MA was1.08:1and the catalystcontent was0.10%(mol), the product with high molecular weight was obtained after3hours polycondensation at220℃. FT-IR and1H-NMR showed that there were samecompositions between methylsuccinc acid and1,4-butanediol in the molecular chain ofthe polyester. DSC and TG results showed that glass transition temperature of thepolyester was-47°C, and the molecular weight had little influence on glass transitiontemperature. The polyester began to decompose under temperature higher than372.60℃,and stopped at405.12°C with the max decomposition rate-18.92%/min at390.31°C. Itwas found that the plasticating effect and resistance transferencet of PBMS on PVC wasbetter than low molecular weight materials.The copolyester was prepared using dimethyl terephthalate (DMT), MSA and BDOas raw materials. The effect of DMT content and catalyst on copolyester properties wasstudied. It was found that molecular weight of the copolyester without clear changingwith the increasing of DMT content, while the coefficient of dispersion increased. Thebiggest catalytic efficiency was obtained when tetrabutyl titanate was compounded withzinc oxide. FT-IR and1H-NMR showed that the product was the target copolyester. DSCand TG results showed that glass transition temperature of the copolyester increased withincreasing of DMT, and thermal performance of the copolyester was improved.