Studies on Manufacturing, Mechanical Properties and Structure of Poly(butylene adipate-co-terephthalate)-based Green Composites Modified by Coconut Fibers

Proper design and manufacturing of biodegradable composites containing natural fibers is highly demanded to improve its functional properties and reduce effects of the mechanical-thermal degradation at the same time. Therefore investigation of poly(butylene adipate-co-terephthalate) (PBAT) modified with coconut fiber (CF) was performed to analyze changes in selected properties of the modified polymer, occurring upon various amounts of CF and different conditions of processing of blends composed of PBAT and CF. Changes in basic parameters of the extrusion process occurring upon two different plasticizing systems, as well as in mass flow rate, mechanical properties, and structure of PBAT/CF composites were examined. It was found that the design of a plasticizing system essentially influenced energy consumption and stability of the processing procedure as well as properties of manufactured materials. Increase in the weight fraction of CF introduced into the polymer matrix caused increase in rigidity and hardness of the composite and reduction in its strength and ability to deform. No effect of the processing conditions on adhesion at the phase boundary was found. All the prepared composites showed strong adhesion between components. Moreover, based on MFR results it was found occurrence of the mechanical-thermal degradation of both phases, especially the dispersed phase.