Desenvolvimento de adesivos à base de polímeros de glicerol reforçados com nanowhiskers de celulose

Abstract

One of the main worldwide research fields in materials is the development of biodegradable materials capable of replacing petroleum-based materials. Biodiesel is currently the material that has the greatest potential for substitution non-renewable fuels, however this generate glycerol as a by-product, produced on a large scale, however its current demand in applications in the pharmaceutical, food and chemical industry is lower its production. Cellulose nanowhiskers are biodegradable and bio-renewable materials and are already widely studied as reinforcements in polymer matrices, increasing mechanical and thermal properties. The combination of these two materials is already being analyzed independently, and both have potential application in a specific sector: adhesives. The use of “green” adhesives underwent expansion, over the need for replacement of commercial synthetic adhesives. In view of this, a new biodegradable material based on glycerol and NWC (cellulose nanowhiskers) was synthesized by polycondensation and used as a wood adhesive. In this work the synthesis and properties of glycerol-based adhesives with NWC at 5, 10 and 20% by mass were studied for use as green adhesives used in Angelim pedra (Hymenolobium petraeum Ducke) wood joints. Single lap shear tests were carried out according to ASTM D906, composites with 10 and 20% NWC showed the best tensile results. In addition to mechanical tests, the adhesive was characterized by DSC, TGA (non-isothermal Flynn-Wall-Ozawa) in which it was possible to observe that there was a decrease in activation energy (Ea) as the concentration of cellulose nanowhiskers increased. The presence of cellulose nanowhiskers was verified through the characteristic bands of the main cellulose functional groups as found by FTIR analyses.