Extração e caracterização das fibras do mamoeiro

Abstract

The present dissertation studied the extraction and characterization of the papaya tree fibers, as well as the influence of the location, size of the papaya bast sample and the percentage of fibers extracted by two extraction methods: the biological and the physical. After that, the physicalmechanical and chemical properties of the extracted fibers were evaluated as tensile strength (tensile, modulus of elasticity, tenacity and elongation), crystallinity and wettability. In both processes, all the fibers presented cellulose type 1, characteristic of the vegetable fibers, demonstrating that there was no chemical modification of the fibers even when they were submitted to the physical process. The properties of tensile strength were larger for the fibers 2 NBT obtained by the physical process (tenacity 25 cN / tex and elongation 1.5% region 2 of the bast), because in this process there is control of the variables of the process, thus there is greater performance of the fibers obtained and greater reproducibility of these results. Consequently, it is also in this process that the fibers are more superficially uniform, hydrophilic (contact angle 78.2 ° region 2 of the bast) and with higher crystallinity (65.2% region 1 of the bast). The biological process, in turn, produces fibers with more residues on the surface, with low density (0.64 g/cm3 region 3 of the bast), with hydrophobic characteristics (contact angle 98 ° region 3 of the bast) and obtained two times more yield of extracted fibers (14.5% region 2 of the bast) when compared to the physical process. These results show that from the bast region of the papaya tree, the size of the sample and the type of extraction process (biological and physical), it is possible to obtain vegetable fibers with higher extractive yield and varied properties. In this way, it favors a greater applicability of papaya tree fibers.