Transparency, ultraviolet transmittance, and miscibility of poly(lactic acid)/poly(methyl methacrylate) blends

Poly(lactic acid)/poly(methyl methacrylate) (PLA/PMMA) blends were prepared by melt compounding technique. The miscibility of PLA/PMMA blends at various blending ratios (i.e. 80/20, 60/40, 40/60, and 20/80) was investigated using a dynamic mechanical analyzer (DMA) and solvent uptake experiment. The solvent uptake experiment was conducted to estimate the interaction of PLA/PMMA blends based on the calculation of Flory–Huggins interaction parameter (χ12). DMA results revealed that only single glass transition temperature (Tg) existed along the PLA/PMMA blends. Smallest χ12 (i.e. ？0.03) was found on the PLA/PMMA20 blend, suggesting interaction between PLA and PMMA at this composition. The incorporation of PMMA slightly improved the UV protection properties of the PLA/PMMA blend, while maintaining their optical transparency