Engenharia de Materiais
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/17
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2 resultados
Resultados da Pesquisa
- Properties of lignocellulosic composites of coffee husk filled polypropylene(2020-01-10) LEAL, H. D. A.; BABETTO, A. S.; BONSE, B. C.© 2020 Author(s).Ground coffee husk has been incorporated into polypropylene (PP) at 20, 30 and 40 wt%, along with a PP maleated compatibilizer at 10 wt% relative to the coffee husk, by means of a co-rotating twin-screw extruder and subsequent injection molding into test specimens. In relation to neat PP, the 40 wt% composite showed an increase in flexural strength, flexural modulus, tensile modulus and heat distortion temperature of about 35, 90, 75 and 45%, respectively. However, strain at break, impact and tensile strength decreased by around 95, 40 and 20%, respectively. The presence of coffee husk practically did not affect PP melt temperature, but increased both composite's degree of crystallinity, measured by DSC, and temperature at maximum degradation rate, measured by TGA.
- Sawdust reinforced polypropylene: Effect of plasticizer incorporation method and properties(2018-07-11) MAZARIM, G. C.; BONSE, B. C.© 2018 Author(s).Polypropylene reinforced sawdust composites containing paraffinic and vegetable plasticizer, at 5 and 10 wt%, were prepared according to two methods. In the first method, PP, sawdust, compatibilizer and plasticizer were pre-mixed, extruded in a co-rotating twin-screw extruder and injection molded. In the second, plasticizer was added to the extruded composite pellets and then injection molded. The addition of plasticizer reduced tensile and flexural strength, as well as elastic modulus of the composite, and increased impact strength, tensile strain at break and toughness. As to plasticizer type, both had similar effects on impact strength, tensile strain at break and flexural modulus. With the paraffin oil, the increase in toughness of the PP sawdust composite was higher and the decrease in tensile and flexural strength was lower compared to the vegetable oil. Except for impact strength and flexural modulus the method of plasticizer incorporation, statistically, showed no difference in the investigated composite properties; however, deviation around the mean was higher when the plasticizer was added prior to injection molding, compared to addition in the pre-mixing stage.