An experimental study of water absorption in polyester composites reinforced with macambira natural fiber

The use of raw materials from renewable sources, such as vegetable fibers, for example, has been the subject of several studies and researches. One major disadvantage in the use of vegetable fibers in polymer composites is their hydrophilic nature which provides weak interfacial adhesion in polymer-fiber composites. Due to its importance, the purpose of this paper is to present an experimental study of water absorption in unsaturated polyester composites reinforced with macambira natural fiber. The studied samples have weight composition 30% macambira fiber and 70% unsaturated polyester, with dimensions of 2062063 mm(3) and 2062066 mm(3). Tests for water absorption were performed by immersing the samples in a bath of distilled water at 25, 50 and 70 degrees C, and water uptake was measured gravimetrically along the process. Results of the micrographs (SEM), moisture content and area / volume relationships of the composites are shown and analyzed.