Full text
| |
| Author(s): |
Joyce Rodrigues de Araujo
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Química |
| Defense date: | 2009-04-08 |
| Examining board members: |
Marco Aurelio De Paoli;
Walter Ruggeri Waldman;
Ines Joekes
|
| Advisor: | Marco Aurelio De Paoli |
| Abstract | |
Natural short fibers used as reinforcing agent in polymers improve their mechanical properties and may substitute inorganic reinforcing agents, produced from non renewable resources, like fiberglass, with the additional advantages of being lighter, less abrasive to the processing equipment and biodegradable. In the first part of this work the formulation and the processing conditions were studied in order to optimize the mechanical properties of the composite of high density polyethylene, HDPE, and curauá fibers. To determine the best formulation we tested: fiber content, type and content of coupling agent and processing conditions (screw rotation speed and temperature profile during extrusion). The aspect ratio and geometric parameters of the fibers before and after processing of the composites were determined by statistic treatment of the micrographies obtained by optical microscopy. The fiber/matrix phase adhesion, with and without coupling agent, was evaluated by scanning electron microscopy. The composites and the pure materials used for their preparation were characterized by fourier transform infrared spectroscopy, thermal methods (thermogravimetry and differential scanning calorimetry) and by measurement of the tensile, flexural and impact mechanical properties. The degradation and stabilization of the composites was monitored by environmental and accelerated aging tests of composite samples with and without stabilizing additives, to evaluate the durability of the composites and the effect of the additives. We conclude that HDPE composites reinforced with curauá fibers have properties comparable to commercially produced composites of HDPE reinforced with fiberglass. (AU) | |