Study On Properties Of Plasticizers Of PLA/PBS Blending Material

In this paper, diethylene glycol adipate (DEAP) and neopentylglycol adipate (NPAP) were synthesized from adipic acid (AA), diethylene glycol (DEG) and neopentyl glycol (NPG) and then Poly (diethylene glycol adipate -co- neopentylglycol adipate) (PDNA) was synthesized from DEAP with NPAP. The structure of the PDNA was investigated using infrared spectrum (IR) and 1H nuclear magnetic resonance (NMR) which showed that it was the expected plasticizer.Meanwhile, choosing dipropylene glycol dibenzoate (DPGDB), glycerol triacetate (GTA)and glycerol tribenzoate as monomer plasticizers. The properties of four plasticizers with PLA/PBS blends were investigated by differential scanning calorimetry apparatus (DSC), polarizing microscope (POM), X-ray diffraction (XRD), scanning electron microscope (SEM), tensile texts, a parallel plate rheometer (PPR) and a thermogravimetric analysis (TGA) and migration texts. Through DSC showed that Tg, Tm decreased with increasing of four plasticizers content, but when the content DPGDB, GTA and GTB of 25 wt%, the Tg of blending materials respectively were from 54.8℃ to 25.2℃、22.5℃ and 25.4℃ which illustrated that three types of haplotype plasticizer for PLA/PBS had good plasticizing effects. Crystallinity of blends increased with adding DPGDB, but the diffraction peak intensity decreased with GTA and GTB, PDNA (wt%>15%) by XRD. SEM proved that four types of plasticizers with content of 25% were separated and PDNA and GTB (wt%< 15%) had good compatibility. Rheological test revealed that the complex viscosity and storage modulus, loss modulus and shear viscosity were decreased with the increase of the content of plasticizer for liquidate the shear thinned phenomenon, simultaneously viscous flow activation energy decreased with the increase of plasticizer content and GTB with 25% declined to 1/10 of the original numerical. The GTA content of 15 wt% showed the plasticizing effect was the most stable and elongation at break reached to 220.9% of the maximum value by mechanical texts. Thermo-gravimetric results showed that adding DPGDB improved the thermal stability of the blending materials. Migration experiment proved that migration rate of the four types of plasticizers was highest in alcohol among alcohol, water and at 60℃ hot air. The migration ability from high to low respectively was GTA, DPGDB, GTB, PDNA.