Obtencao e caracterizacao de compositos de PLA e fibras de taquara-lixa (Merostachys skvortzovii)

Abstract

Biodegradable composites are characterized by having a biodegradable polymer matrix next to a material from a natural source. Composites formed from biodegradable polymers and natural fibers degrade when exposed to fertile soil and moisture, thereby shortening their useful life. In this way they can be used in agriculture to replace the tubes used for planting seedlings in the forest sector made with PVC, which is a polymer derived from petroleum. Among the existing biodegradable polymeric matrices is the Poly (Lactic Acid) – PLA, which is a biodegradable polymer, derived from a renewable source and that has no solvents in its composition. Taquara-lixa fibers come from a natural and renewable source and have good mechanical performance and high availability in the state of Paraná. The objective of this dissertation is to obtain and characterize composites made with PLA and Taquara-lixa fibers in natura in different proportions without binders / compatibilizer, aiming to use the raw material in a sustainable product, since it comes from renewable sources. The composites were characterized by the biodegradation test, water absorption, tensile strength before and after the biodegradation test, FT-IR, thermogravimetric analysis (TGA). The fracture surface was evaluated by scanning electron microscopy, with the purpose of obtaining data that contribute to the application of this material in tubes in agriculture. After exposure to simulated soil, along with analysis of crystallinity, water absorption and mass loss, biodegradation is occurring at 180 days, indicating the proper use of Taquara-lixa in biodegradable composites. The addition of fibers to the composites provided the composites with fragile fracture behavior, in which the longer the exposure time in the simulated soil, the lower the mechanical strength of the PLA / Taquara-lixa composite. Aiming at greater sustainability and less pollution in the environment, it can be concluded that the addition of Taquara-lixa fibers in the PLA matrix promoted alteration in the composite color and accelerated the biodegradation process.