Tunable polymorphic crystal modification, phase transition and biodegradability of poly(1,4-butylene adipate) by a bio-derived metabolite with low molecular weight

Via the H-bond interaction, the 3,4-dihydroxy hydrocinnamic acid (HCA, a low molecular weight com-pound with biocompatibility) decreased the melt-crystallization temperature (T-c), crystallization rate and relative degree of the crystallinity of the poly(1,4-butylene adipte) (PBA) polyester. In the case of the lower weight fraction of the HCA (f(HCA) = 1-5%), the H-bond exists between the -CH2 segment of the HCA and -C=O group of the PBA. When f(HCA )= 10-30%, there is a larger H-bond strength between the HCA and PBA, and the -C=O segment of the HCA interacts with the -CH2 segment of the PBA. The HCA facilitated the generation of the PBA alpha-modification at a lower T-c and accelerated the transition from the beta-to alpha-phase. The polymorphism and phase transition of the PBA could be tuned by the HCA. Lower f(HCA) enhanced slightly the thermal degradation temperature (T-d), but higher f(HCA )decreased the T-d of the PBA. The HCA increased the biodegradability of the PBA. Mechanisms on reduced critical T-c of the PBA alpha-modification (T-c,T-alpha), speeded up phase transition, enhanced biodegradability and dual effects of the HCA on the thermal stability of the PBA, were also proposed and discussed systematically and in depth. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

The research found that 3,4-dihydroxy hydrocinnamic acid (HCA) interacts with poly(1,4-butylene adipate) (PBA) through hydrogen bonding, resulting in a decrease in the crystallization temperature, rate, and degree of crystallinity. The content of HCA can be used to control the polymorphism and phase transition of PBA, as well as enhance its biodegradability.