Miscibility and phase behavior of reactively compatibilized poly(lactic acid)/poly(butylene succinate) bio-blends using various rheological analyses

This study focuses on the compatibilization of PLA/poly(butylene succinate) (PBS) blends using mono- and multi-epoxide POSS (MoEpPOSS and MuEpPOSS) nanoparticles, from a rheological point of view for the first time in the literature. The addition of PBS to PLA decreased the complex viscosity, storage modulus, and loss modulus, indicating weak interactions between polymers. However, the incorporation of MoEpPOSS and MuEpPOSS increased the complex viscosity and storage modulus due to the formation of long polymeric chains or complex polymeric structures through interactions between the epoxide groups of POSS and the end groups of the polymers. The effect was more significant with MuEpPOSS because MuEpPOSS has multiple epoxide groups in its cage structure, leading to stronger interactions with the polymers. POSS incorporation resulted in semicircular and arc-shaped curves in the Cole-Cole plots, indicating better dispersion, phase homogeneity, and compatibility. The introduction of POSS also influenced the dynamic loss tangent (tan δ) versus frequency (ω) plot. When POSS was introduced, the tan δ peak decreased and shifted to a higher frequency, indicating improved compatibility, and enhanced interfacial adhesion. These findings indicated that the addition of epoxy-POSS nanoparticles can effectively compatibilize PLA/PBS blends and enhance their rheological properties, potentially improving their overall performance for various applications