PBAT biocomposite with banana pseudo-stem fibers

11/28/2022

With increasing environmental problems presented today due in part to plastic pollution, new trends are emerging to deal with this crises. One approach takes advantage of bioplastics to substitute synthetic polymers where PBAT blends are a promising candidate. Natural fibers, as agricultural waste, have been previously used as reinforcements for bioplastic blends, but the novelty of this project lies in repurposing banana pseudo-stem fibers. These fibers were ellected as excellent candidates due to their high cellulose content, high tensile and flexural strength, high stiffness and low microfibrillar angle (11°). In order to produce the composites the fibers were extracted from three regions of the trunk, dried, grinded and subject to carefully designed treatments, and blended, by extrusion, with PBAT pellets to obtain filaments with 2, 5 and 8 wt% in fiber powder. Composites were characterized by SEM, FTIR spectroscopy, TGA, water adsorption, DMA and tensile tests. Composites reinforced with grinded fibers from the middle sheaths presented an interaction between the fillers and the polymer matrix, however, the addition of powders lead to composites with improper dispersive mixing, lower thermal stability, lower tensile strength and higher water absorption tendencies. Composites reinforced with grinded fibers from the exterior sheaths were the only ones that presented enhanced mechanical, thermo-mechanical properties and water absorption capacity. Therefore, these powders are a good reinforcement/fillers for PBAT that allow to reduce the cost of the materials without compromising its original properties and behavior of this biodegradable polymer.

Authors in the community:

• 

  R

  Rita Serôdio

  ist198652

Supervisors of this institution:

• 

  A

  Ana Clara Lopes Marques

  ist45873

chemical-engineering - Chemical engineering

por - Portuguese

Instituto Superior Técnico