Synthesis and characterization of biodegradable aliphatic-aromatic nanocomposites fabricated using maleic acid-grafted poly[(butylene adipate)-co-terephthalate] and organically modified layered zinc phenylphosphonate

摘要

A new series of biodegradable aliphatic-aromatic nanocomposites containing maleic acid-grafted poly[(butylene adipate)-co-terephthalate] (g-PBAT) and organically modified layered zinc phenylphosphonate (m-PPZn) were successfully synthesized through transesterification and polycondensation processes with covalent linkages between the polymeric and inorganic materials. Fourier transform infrared and C-13 NMR spectra demonstrate the successful grafting of maleic acid to PBAT. The morphology of g-PBAT/m-PPZn nanocomposites was investigated using wide-angle X-ray diffraction and transmission electron microscopy. Results showed that the stacking layers of m-PPZn were distributed and intercalated into the g-PBAT polymer matrix. The incorporation of m-PPZn into the g-PBAT matrix significantly enhanced the storage modulus at -70 degrees C as compared to that of neat g-PBAT. A reduction in thermal stability was observed for all g-PBAT/m-PPZn systems, which is probably due to the lower thermal stability of m-PPZn. The biodegradation of neat g-PBAT copolymers and g-PBAT/m-PPZn nanocomposites was investigated using lipase from Pseudomonas sp. The degradation rates of neat g-PBAT copolymers decrease in the order g-PBAT-80 > g-PBAT-50 > g-PBAT-20. The faster degradation rate of g-PBAT-80 is a result of the higher content of adipate acid units and the chain flexibility of the polymer backbone. Furthermore, the weight loss increases as the loading of m-PPZn increases, indicating that the presence of m-PPZn improves the degradation of the g-PBAT copolymers. This result might be accounted for by the lower degree of crystallinity for g-PBAT/m-PPZn nanocomposites. (c) 2019 Society of Chemical Industry