Mechanical Properties of Rice Husk Ash/Polypropylene Composites

Abstract

ABSTRACT:The technical viability of using rice husk ashes (RHA) as alternative fillers in polypropylene was studied. Three types of RHA, white rice husk ash (WRHA), black rice husk ash (BRHA) and amorphous rice husk ash (AMRHA) at 10-40wt% filler loading were investigated. The RHA composites were compounded by twin screw compounders and the mechanical properties of the composites evaluated. Incorporation of the RHA fillers increased the flexural modulus of the composites, particularly the BRHA composities. Modulus of the RHA composites were found to be in good agreement with theoretical values predicted by equation of Lewis and Nielsen. The increase in modulus was offset by lowering of the tensile strength, elongation at break and impact properties. Theoretical treatments of the ultimate tensile strength performed based on the model proposed by Nicolai and Nicodemo showed reasonably good agreement. The mechanical properties of the RHA composites were of comparable values with the prepared polypropylene composites filled with commercial Neu burg silica. Transformation of the crystalline RHA to amorphous RHA resulted in composites with improved tensile strength. No coupling agent was used in this study.KEY WORDS Rice Husk Ash / Filler / Polypropylene / Composites / Mechanical Properties/ Incorporation of fillers into a polymer is known to cause substantial changes to the mechanical properties of the composities. As polymer composites are increasingly used in various mechanical applications, the mechanical properties are perhaps the most basic and important behaviors that need to be investigated in order to evaluate the performance of the composities when they are subjected to stress.term of modulus of elasticity, ultimate tensile strength, impact resistance, etc. The term mechanical is applied for this category of properties because they are often used to indicate the suitability of a material for use in mechanical applications, parts that carry a !oak, absorb shock, etc. 1 The principal objective of this study is to investigate the technical viability of using the rice husk ashes which are usually regarded as waste products as alternative low cost fillers in polypropylene. In this investigation, the mechanical properties of the polypropylene/ rice hush ash (RHA) composites are investigated in term of their modulus, tensile and impact properties. Modulus is a measure of The basic characterization of the mechanical properties are usually determined by tests resulting in various deformation versus stress dependencies, for instance the stressstrain diagrams. Examinations of such dependencies yield mechanical characteristics in * To whom correspondence should be addressed. 1002Mechanical Properties of RHA/PP Composites the stiffness of a material subjected to shear loading. Addition of filler normally improves the stiffness of the composities. Tensile test is among the most widely employed test method to characterize the mechanical properties of composites. From such a test, enomorous amount of important information m...

Rice husk ash – A valuable reinforcement for high density polyethylene

“…Most of the rice husk is used for such mundane applications as bedding material for animals, fuel and landfill. The novel use of rice husk and RHA as fillers in thermoplastic polymer composites has attracted much attention recently [6][7][8]. Depending upon the incineration conditions, two types of ash are produced i.e., white rice husk ash (WRHA) and black rice husk ash (BRHA) [9].…”

“…Depending upon the incineration conditions, two types of ash are produced i.e., white rice husk ash (WRHA) and black rice husk ash (BRHA) [9]. White RHA has smaller specific surface area (1.4 m 2 /g) than the black colored one and its particle size is reported to be about 50 lm [6]. In the following sections, RHA refers to specifically white RHA.…”

Aplicabilidade das cinzas da casca de arroz

“…Um dos primeiros trabalhos preliminares sobre o uso de cinzas de casca de arroz como carga em polímeros foi reportado em 1975 por Haxo e Mehta 34 , e o uso dessa carga em polietileno foi reportado recentemente por Fuad et al 35 , que observaram um aumento significativo no módulo de flexão do compósito, sendo comparável ao de outras cargas comerciais utilizadas, como por ex., a mica. Entretanto, Ishak e Bakar 36 foram os primeiros que sugeriram a utilização tecnológica de cinzas de casca como carga de borracha.…”

The effects of natural zeolite and silane coupling agents on melting and crystallization behaviour of polypropylene

“…In spite of the advantages of the fillers, the incorporation of the hydrophilic fillers into PP leads to the loss in the mechanical properties and also the changes in the thermal properties of PP. However, the mechanical properties of polymer composites can be improved by using silane coupling agents as those reported in the literature [1][2][3][4][5][6][7].Also, the previous study done by our group on the effects of interfacial interactions on the mechanical properties of PP-natural zeolite composites has indicated that silane coupling agents provide significant improvement in the mechanical properties of the composites [8]. Furthermore, although there are many studies related to the effects of silane coupling agents on the mechanical properties of polymer composites [1][2][3][4][5][6][7][8], the number of studies related to the effects of filler modification on the thermal properties of the composites is limited [9][10][11].…”

“…In spite of the advantages of the fillers, the incorporation of the hydrophilic fillers into PP leads to the loss in the mechanical properties and also the changes in the thermal properties of PP. However, the mechanical properties of polymer composites can be improved by using silane coupling agents as those reported in the literature [1][2][3][4][5][6][7].…”