Crystallization manipulation of poly(butylene succinate) via hydrazide-based self-assembled hydrogen-bonding interactions

Self-assembled nucleating agents based on hydrogen bonding interactions have been increasingly used to manipulate the crystallization behavior of polymer materials, yet the specific working mechanism is not well unrevealed. In this study, the hydrazide-based nucleator structure of bis-(mono-methyl succinyl)dihydrazide (MSAD) is randomly incorporated in poly(butylene succinate) (PBS) chains to prepare a series copolymers of PBS-co-MSAD. It is confirmed that the multiple hydrogen-bonding interactions strengthen as the content of the MSAD segment increases, leading to a remarkable elevation of crystallization temperature. Meanwhile, the primary nucleation density of PBS is significantly raised without changing crystal modification. The formation of a pre-ordered network of hydrogen-bonding structures during non-isothermal crystallization is confirmed by rheological measurement and Fourier transform infrared spectroscopy investigation, which immediately induces the crystallization of PBS segments once strong enough. In addition, the melt crystallization mechanism of PBS-co-MSAD with heterogeneous hydrogen-bonding segments is elucidated in detail by combining a self-nucleation protocol.