Generation of Compositional‐Gradient Structures in Biodegradable, Immiscible, Polymer Blends by Intermolecular Hydrogen‐Bonding Interactions

Abstract

Abstract A biodegradable, immiscible poly(butylenes adipate‐ co ‐butylenes terephthalate) [P(BA‐ co ‐BT)]/poly(ethylene oxide) (PEO) polymer blend film with compositional gradient in the film‐thickness direction has been successfully prepared in the presence of a low‐molecular‐weight compound 4,4′‐thiodiphenal (TDP), which is used as a miscibility‐enhancing agent. The miscibilities of the P(BA‐ co ‐BT)/PEO/TDP ternary blend films and the P(BA‐ co ‐BT)/PEO/TDP gradient film were investigated by differential scanning calorimetry (DSC). The compositional gradient structure of the P(BA‐ co ‐BT)/PEO/TDP (46/46/8 w/w/w) film has been confirmed by microscopic mapping measurement of Fourier‐transform infrared spectra and dynamic mechanical thermal analysis. We have developed a new strategy for generating gradient‐phase structures in immiscible polymer‐blend systems by homogenization, i.e., adding a third agent that can enhance the miscibility of the two immiscible polymers through simultaneous formation of hydrogen bonds with two component polymers.