Compatibility characterization of poly(lactic acid)/poly(propylene carbonate) blends

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 44; no. 1; pp. 94 - 101
• Main Authors: Ma, Xiaofei, Yu, Jiugao, Wang, Ning
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-01-2006; Wiley
• Subjects: Applied sciences; blends; compatibility; Exact sciences and technology; extrusion; Organic polymers; Physicochemistry of polymers; poly(lactic acid); poly(propylene carbonate); Properties and characterization; Thermal and thermodynamic properties; Polymer blends; Property composition relationship; Mechanical properties; Experimental study; poly(propylene carbonate); Thermal stability; Intermolecular interaction; Lactic acid polymer; Aliphatic polymer; extrusion; Miscibility; Thermodynamic properties; Polycarbonate; compatibility; poly(lactic acid); blends
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/polb.20669

The compatibility of poly(lactic acid) (PLA)/poly(propylene carbonate) (PPC) blends was investigated with Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile testing. The PLA/PPC blends were prepared over the whole composition range. FTIR spectroscopy revealed that there were several specific interactions between the chains of PLA and PPC: the interaction between CH and OC and CO···OC or CO···OC dipole–dipole interactions. Moreover, PLA and PPC were compatible. DSC indicated that PLA and PPC were partially miscible but compatible to some extent because of the similar chemical natures of the blend components. TGA showed that the compatibility of PLA and PPC enhanced the thermal stability of PPC in the blends. As calculated by the Horowitz–Metzger equation, the activation energy for decomposition (Et) of PPC in PLA/PPC (70/30) was 200.6 kJ/mol, whereas Et of pure PPC was only 56.0 kJ/mol. A study of the mechanical properties versus the composition and the strain versus the stress illustrated that there was good compatibility between PLA and PPC, and the phase inversion of the PLA/PPC system occurred between 70 and 60 wt % PLA in the PLA/PPC blends. The Pukanszky model gave credit to very strong interfacial adhesion between PLA and PPC. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 94–101, 2006