Mechanical, morphological, thermal properties and hydrolytic degradation behavior of polylactic acid/polypropylene carbonate blends prepared by solvent casting

Abstract

The preparation of polylactic acid (PLA) and polypropylene carbonate (PPC) blend films by using the solvent casting method is to improve the properties of pure PLA. The blends' mechanical and thermal properties, morphological as well as hydrolytic degradation behavior are evaluated. The tensile test proved that the increase of PPC from 0 wt% to 75 wt% could improve the elongation of pure PLA when the graph showed a significant increase of the elongation from 10% to 1000%. Scanning Electron Microscopy (SEM) supported the significant increase in elongation of the blends when it shows a definite phase separation in 75/25 PLA/PPC, where 25% of PPC has formed islands in the PLA matrix. Differential scanning calorimetry indicates the partial miscibility of the blends where two peaks of the glass transition temperature moved towards each other when the amount of PPC increases. Fourier transform infrared (FTIR) spectroscopy revealed a possible intermolecular interaction between two polymers, which affects the miscibility of the blends. Finally, the hydrolytic degradation test indicates that the degradation started from the PLA phase and the blends' degradation rate decrease as wt% of PPC increase.

Green Composites from a Bioplastic Blend of Poly(3-hyroxybutyrate-co-3-hydroxyvalerate) and Carbon Dioxide-Derived Poly(propylene carbonate) and Filled with a Corn Ethanol-Industry Co-product

“…Similar open polymeric networks in other PHA/PPC blends were observed by Yang and Hu . The surface morphology of pristine PPC was observed as a featureless flat fracture surface by Haneef et al PHBV/PPC (60/40) and (40/60) blends with (Figure c,g, respectively) and without (Figure b,f, respectively) the cross-linking agent showed smoother surfaces compared to PHBV. No distinct phases of PHBV and PPC were observed in Figure b,c,f,g, which makes it hard to distinguish between individual components in the blend formulations.…”

Crystallization, Structure and Significantly Improved Mechanical Properties of PLA/PPC Blends Compatibilized with PLA-PPC Copolymers Produced by Reactions Initiated with TBT or TDI

“…The work carried out by Zhao [ 24 ] et al shows that the elongation at break of PLA/PPC blends is much higher than neat PLA (1.9%). PPC and PLA are incompatible [ 25 , 26 , 27 ], which negatively impact its mechanical property. Phase separation in PLA/PPC blends was observed [ 25 , 26 ] and the modulus and tensile strength of the blend was reported lower than neat PLA.…”

“…PPC and PLA are incompatible [ 25 , 26 , 27 ], which negatively impact its mechanical property. Phase separation in PLA/PPC blends was observed [ 25 , 26 ] and the modulus and tensile strength of the blend was reported lower than neat PLA. Flodberg [ 27 ] et al studied the PLA/PPC blend with more than 30wt% of PPC, and noticed that severe phase separation could occur, resulting in a very low elongation at break and toughness.…”

Miscibility, crystallization and mechanical properties of poly[(3‐hydroxybutyrate)‐co‐(4‐hydroxyvalerate)]/poly(propylene carbonate)/poly(vinyl acetate) ternary blends

“…The most extensively studied and produced P34HB binary blends are P34HB/polylactide (PLA), 18,19 P34HB/poly(ethylene glycol), 20 P34HB/poly(butylene succinate) (PBS), 21 P34HB/PHB, 22 P34HB/poly[(3-hydroxybutyrate)-co-(3-hydroxyvalerate)] (PHBV), 23,24 etc. Binary blends of PPC, such as PPC/PLA, 25,26 PPC/PHBV, 27 PPC/poly[(butylene adipate)-coterephthalate], 28 PPC/PHB, 29 PPC/PBS 30 and PPC/poly(butylene carbonate), 31 have been investigated intensively in industry and academia. However, unfortunately, there have been few investigations concerning the blends of biodegradable P34HB and sustainable PPC.…”