Impacts of chain extenders on thermal property, degradation, and rheological performance of poly(butylene adipate-co-terephthalate)

To improve comprehensive properties of poly(butylene adipate-co-terephthalate) (PBAT), especially thermal stability, reactive extrusion method was used to modify PBAT. Branch and micro cross-linking structure of PBTA was produced with hexanediol diglycidyl ether (HDGE), polyethylene glycol diglycidyl ether (PEGDGE), and styrene–methyl methacrylate–glycidyl methacrylate terpolymer (KL-E4370) as the chain extender (CE), demonstrated through differential scanning calorimeter, Vicat softening point testing (VSP), gel permeation chromatography, rheological measurement, and scanning electron microscopy. The molecular weight, the complex viscosity, and the viscoelasticity of modified PBAT were improved by increasing the CE molecular weight. The crystallization temperature and VSP were also increased. Meanwhile, it showed that the hydrolysis resistance of PBAT was improved and its degradation performance was decreased. Furthermore, when KL-E4370 was added, PBAT has the best comprehensive performance. Graphic abstract: [Figure not available: see fulltext.]