Ndazi, Bwire S.; Tesha, J. V.; Karlssion, S.; Bisanda, Elias T. N.
Description:
Rice husks are amongst the typical agricultural
residues, which are easily available in huge amounts. They
have been considered as raw material for composites
panels’ production. However, the major hindrance in rice
husks utilization for composite manufacture lies in the lack
of direct interaction with most adhesive binders to form the
anticipated interfacial bonds. Rice husks are highly siliceous
and have poor resistance to alkaline and acidic
conditions. Manufacture of rice husks composites panels
having good interface bond is difficult and largely dependent
on a proper understanding of the interaction between
the husks and the binder. This paper presents and discusses
results on the production of composites boards from a
mixture of rice husks and wattle (Acacia mimosa) tannin
based resin. The experimental results have shown that the
‘as received rice husks’ when blended with alkali-catalyzed
tannin resin do not result in optimum composite panel
properties. However, it was found that a slight physical
modification of the rice husk particles by hammer-milling
resulted in drastic improvements in the interfacial bond
strength and stiffness of the composites panels from
0.041 MPa to 0.200 MPa and 1039 MPa to 1527 MPa,
respectively.