Modification of Aged PBAT via Chain Extension and Bamboo Filler Reinforcement

An enhanced modification approach for aged polybutylene adipate terephthalate (PBAT) through the incorporation of chain extenders and bamboo filler was investigated in this study. A systematic analysis was conducted to evaluate the effects of chain extension and bamboo filler reinforcement on the molecular weight (via GPC), thermal properties, thermal stability, processability, and mechanical properties (assessed by DMA, FTIR, SEM, and mechanical testing) of PBAT. The results indicated that the chemical structure of PBAT remained unaltered after modification, while its overall properties were notably improved. In terms of thermal properties and processability, the modified aged PBAT achieved performance levels comparable to or exceeding those of newly produced PBAT (NPBAT). Specifically, chain extension with 4% diphenylmethane diisocyanate (MDI) led to a significant enhancement in mechanical properties, restoring the tensile strength and elongation at break to 54% and 37% of NPBAT, respectively. Furthermore, after bamboo filler reinforcement subsequent to chain extension, the tensile strength of the modified aged PBAT—whether using MDI or 4% TDI—exceeded that of NPBAT reinforced solely with bamboo filler (NPBAT/BF). Among the formulations tested, the sample modified with 4% MDI exhibited the most pronounced improvement, achieving a tensile strength equivalent to 136% of that of NPBAT/BF. These findings demonstrated the promising potential of the modified aged PBAT material for practical applications.