Physical Properties and Polymorphism of Acrylic Acid-Grafted Poly(1,4-butylene adipate-co-terephthalate)/Organically Modified Layered Double Hydroxide Nanocomposites

Novel and biodegradable acrylic acid-grafted poly(1,4-butylene adipate-co-terephthalate)/organically modified layered double hydroxide (g-PBAT/m-LDH) nanocomposites were synthesized through the polycondensation and transesterification process, with the covalent linkages between the polymer and the inorganic materials. X-ray diffraction and transmission electron microscopy were used to characterize the structure and morphology of the g-PBAT/m-LDH nanocomposites. The experimental results show that the m-LDH was exfoliated and widely distributed in the g-PBAT matrix. The addition of m-LDH into the g-PBAT extensively improved the storage modulus at −90 °C, when compared to that of the pure g-PBAT matrix. The effects of the minor comonomer of the butylene terephthalate (BT) unit and the addition of m-LDH on the crystallization behavior, and the polymorphic crystals of the g-PBAT at numerous crystallization temperatures, were examined, using a differential scanning calorimeter (DSC). The data indicate that the minor comonomer of the BT unit into g-PBAT can significantly change the starting formation temperatures of the α-form and ꞵ-form crystals, while a change in the starting formation temperatures of the α-form and ꞵ-form crystals using the addition of m-LDH into g-PBAT is not evident.