Synthesis And Characterization Of Poly(Butylene Succinate)

In this paper, Poly (butylene succinate) (PBS) was synthesized from the raw materials of succinic acid with 1,4-butanediol via melt polycondensation. The synthetic technology, the chain extending and the situ intercalation of PBS was studied.Through study on the synthesic technology, the results showed that when the molar ratio of SA and BD was 1:1.1, the temperature maintained around 170℃ at esterification stage and around 230℃ at polycondensation stage and used the composite catalyst system of stannous chloride (SnCl2) and p-toluenesulfonate as a catalyst, the intrinsic viscosity of product was higher and the side reaction was fewer. The structure of the polyester product was investigated via Fourier-transform infrared spectroscopy (IR) which showed that it had the characteristic peaks of aliphatic polyester. Using differential scanning calorimetry measured the thermal properties of PBS, the results showed that the melting temperature (Tm) was around 115℃. And, the crystallization temperature (Tc), melting enthalpy (ΔHm) and crystallinity degree (Xc-DSC) reduced with the increasing of intrinsic viscosity of PBS. Through testing the mechanical properties of PBS,the tensile strength and elongation at break increased significantly with the increasing of intrinsic viscosity of PBS.Analyzing PBS modified by chain extender via infrared spectroscopy (IR) showed that the polymer was the expected products. By DSC, Ubbelohde viscometer and electronic universal testing machine to study the performance of the chain extender product, the results indicated that with the increase in the amount of TDI, the crystallization temperature (Tc), crystallinity degree (Xc-DSC), melting enthalpy (ΔHm) of the product gradually decreased, while the intrinsic viscosity, tensile strength and elongation at break showed a trend of rising at first and then decreasing, and when the.TDI amount was 1.5wt%, PBS had the highest viscosity, tensile strength and elongation at break. Comparing the effect of the TDI and IPDI with the same amount, The intrinsic viscosity and the tensile strength of the chain extending of PBS with TDI was higher, and the elongation at break was lower.Analyzing PBS/OMMT nanocomposites by infrared spectroscopy (IR) proved that the polymers was the expected products. The X-ray diffraction (XRD) indicated that PBS chains intercalate into the intergalleries of organo-MMT. The thermal properties, the spherulite structure, the morphologies of the fracture surfaces, the MFR, morphology and the tensile properties of these nanocomposites were determined by differential scanning calorimeter(DSC), polarizing optical microscopy, scanning electron microscopy (SEM), melt flow index tester, rotating flat rheometer and electronic universal testing machine. When the content of organo-MMT was 0.3 cot%,Tc, Tm, ΔHm, Xc-DSC, tensile strength and elongation at break of the nanocomposites taken maximal value and the diameter of the spherulites and the MFR of nanocomposites taken minimal value. SEM images demonstrated that the organo-MMT fibers are anisotropically dispersed in the polymer matrix. The storage moduli, the loss moduli and the complex viscosities of the nanocomposites increased with increasing organo-MMT loading at all frequencies. In addition, the shear viscosities increased with increasing organo-MMT loading at the low shear rate. Adding OMMT when the experiment began, the MFR, complex xiscosity and shear viscosity of nanocompsite was highest.