Synthesis of bio-based semi aromatic high temperature polyamide PA5T/56 and effect of benzene ring on non-isothermal crystallization kinetics

Bio-based semi aromatic high temperature polyamide PA5T/56 was synthesized by one-step high temperature and high pressure solution polymerization with bio-based monomer pentanediamine. The non-isothermal crystallization behavior of PA5T/56 was studied by differential scanning calorimetry (DSC). Mo equation was used to describe the non-isothermal crystallization kinetics. The activation energy of non-isothermal crystallization was calculated by Kissinger equation. The effect of benzene ring (T) molar content on the non-isothermal crystallization kinetics was investigated. The crystal morphology was observed by optical polarized microscope (POM) and X-ray diffraction (XRD). The results showed that the non-isothermal crystallization activation energy and absolute crystallinity of nylon 5 T/56 first increased and then decreased with the increased of T molar content from 25% to 32.5%. At the same time, the crystal form of polyamide didn’t change. When the molar content of T was 30%, the number of spherulites was the largest, the size was the smallest, the crystallization rate was the fastest, and the crystallization ability was the highest, which indicated that T can play a role in promoting crystallization in polymer molecular chain.