Enhanced Crystallization of Poly(butylene adipate-co-terephthalate) by a Self-assembly Nucleating Agent

Abstract

Poly(butylene adipate-co-terephthalate) (PBAT) is a promising biodegradable flexible polymer but suffers from slow crystallization rate, making it less attractive for some applications like the injection-molded products in comparison with low-density polyethylene (LDPE). This work aimed to accelerate the crystallization of PBAT by adding a self-assembly nucleating agent octamethylenedicarboxylic dibenzoylhydrazide (OMBH). PBAT/OMBH composites with various OMBH contents (0 wt%, 0.5 wt%, 0.7 wt%, 1 wt%, 2 wt%, 3 wt% and 5 wt%) were prepared through melt-mixing. The effect of OMBH on the crystallization behavior, morphologies and mechanical properties of PBAT was investigated. The highest nucleation efficiency value of 59.6% was achieved for PBAT with 0.7 wt% OMBH, much higher than that of 22.7% for PBAT with 0.7 wt% talc. Atomic force microscopy results showed that OMBH formed fine fibers and induced the formation of transcrystalline layers of PBAT. Fourier transform infrared spectroscopy (FTIR) combined with two-dimensional correlation spectra suggested that the intermolecular dipole-dipole N—H⋯O=C interactions but not hydrogen bond between OMBH and PBAT promoted the crystallization of PBAT in the initial period of crystallization. The presence of OMBH did not change the crystal form of PBAT but had positive contribution in enhancing its crystallinity and mechanical properties. This work is essential for preparing PBAT with high crystallization rate, enhancing its potential applications in injection-molded products.