Nanocristais de celulose como reforço eficiente em compósitos poliméricos utilizando monômero de estireno como agente compatibilizante

Abstract

The application of cellulose nanocrystals (CNC) as reinforcement in the development of composite materials has attracted the interest of the academic community and several industrial sectors, due to their physical and mechanical properties, in addition to the characteristics of sustainability, biodegradability and abundance. The aim of the present study was to develop composites of unsaturated polyester matrix increased by 1%, 2% and 3% of CNC, using styrene monomer as a compatibilizing agent, as well as to investigate the interactions between the load and the matrix, and also to evaluate the thermal and mechanical properties of the developed materials. It was observed that the addition of 1% of cellulose nanocrystals increased the flexural and impact resistance of the composite by 28.5% and 49%, respectively. The stiffness was increased by approximately 30% however, there was a decrease in tensile strength of approximately 18.95%, when adding 2% of load to the matrix. The resistance to thermal degradation increased 20oC. There was no difference in the FTIR spectra of composites compared to polyester. The crystallinity index of composites with 1% and 2% CNC was higher than that of the polymer without reinforcement. The addition of CNC in the matrix did not increase the water absorption of the material. The scanning electron microscopy (SEM) analysis indicated that there was a good dispersion and interaction between the CNC and the polyester matrix. Thus, the results obtained in this work, indicate that the methodology used for the development of the composites was efficient, increasing the mechanical and thermal resistance of the materials.