Ground Rice-Hull Ash as a Filler for Rubber

Abstract

A ground rice hull ash prepared by a new burning process has been found to be a moderately reinforcing filler for rubber. This filler, 85-90% amorphous silica and 10-15% carbon, is made by a controlled incineration process in which the bulk of the organic components of the rice hulls is removed, leaving the skeletal silica structure of the hull intact and in the amorphous state. The resultant ash is easily ground to produce fine particles, generally in the range of 0.1-2.0 μm. This filler does not adversely affect either the vulcanization characteristics or the aging of SBR, natural rubber, nitrile rubber, butyl rubber, neoprene, EPDM, and propylene oxide rubber compounds. As it is predominantly silica, it responds effectively to silane coupling agents in improving properties of the rubber compounds. It is concluded that RHA filler is a satisfactory substitute for MT black and that, in blends with blacks, it can be effectively used as a partial replacement for finer and more reinforcing blacks.

The effect of coupling agent and chemical treatment on rice husk ash‐ filled natural rubber composites

“…Although the use of husk as fuel to produce the energy necessary in grain processing, as a substitute for oil and coal, is a feasible practice, because it allows reduction in oil expenses, other alternatives are conceivable. 1 An early investigation by Haxo and Mehta 1 proved that ground rice husk ash obtained by means of a special burning process is a moderately reinforcing filler for such rubbers as styrene-butodiene rubber (SBR), ethylene propylene diene methylene rubber (EPDM), and natural rubber (NR). A recent study by Ahmad Fuad et al 2,3 observed that the incorporation of rice husk ash into polypropylene has led to a significant increase in flexural modulus of the composites; that is, comparable to that of such other commercial fillers as mica.…”

Possibilities of rice husk ash to be used as reinforcing filler in polymer sector -a review

“…Particle size, surface activity and structure are important factors when evaluating a filler for polymer applications. High structure (OAN at or above 200 mL/100g [48]) is desirable for better processing, because homogeneous dispersion is achieved [86]. Additionally, fine primary particle size (10-100nm) is desirable for high reinforcing degree [87].…”

“…Other kind of elastomers or elastomer blends have been investigated with RHA as filler, such as styrene butadiene rubber (SBR) [86], epoxidized rubber [75] …”

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.…”