Effect of humidity and temperature on the mechanical strength of poly(butylene adipate-co-terephthalate)/canna starch polymer blend

Abstract

Poly(butylene adipate-co-terephthalate)/canna starch (PBAT/TB) polymer blend was prepared using a twin-screw internal mixer (Brabender). The effects of humidity and temperature on the mechanical strength of PBAT/TB materials were carefully evaluated at humidity levels of 35-95% and temperatures of 10-40°C. Moisture content, mechanical properties, and surface morphology (observed using scanning electron microscopy - SEM) were analysed to evaluate the changes in the polymer blend during storage under different conditions. The study results showed that the moisture content of the polymer blend PBAT/TB increased when the environmental humidity increased. When the sample was stored at low temperature (10-25°C) and low humidity (35-55%), the mechanical properties of PBAT/TB decreased slightly after six months of storage, the fracture surface morphology of the sample did not change significantly. When the sample was stored at a high temperature (40°C) and high humidity (95%), the mechanical properties of the sample decreased sharply (~45%), and the surface of the sample material exhibited phase separation between the starch and the PBAT resin matrix.