Thesis-1983-RahmanKuIsmail.pdf (17.87 MB)
Download fileShort fibre woodcellulose as a filler for natural rubber
thesis
posted on 2010-11-23, 11:11 authored by Ku Abd Rahman Ku IsmailThis research work was carried out to investigate the effect
of unregenerated short cellulose fibres from woodpulp on the
properties of rubber vulcanisates. It was also an objective of
this work to find the type of woodpulp which was able to produce
short fibre-rubber composites of good physical properties at a
reduced cost.
A screening procedure was carried out to identify one particular
type of woodcellulose short fibre for detailed investigation.
Mechanical woodpulps containing short cellulose fibres were selected
based on their dispersibility properties in rubber, low cost,
and universatility of application.
Among various types of bonding agents studied, a resorcinolhexamethylenetetramine
(RH) system was found to be most effective
to bond woodcellulose fibre (mechanical type) to natural rubber
-matrix. This was judged by certain properties namely, restricted
equilibrium swelling, yield stress and tear strength.
Restricted equilibrium swelling in particular was established
to be a very useful technique by which the degree of adhesion can
be predicted. In-this technique, the short fibre-rubber composites
were swollen in toluene. for one week, after which, the volume restriction
value, Vr was calculated using the following formula: Vr= (VI - VF)/VI, where VI and VF are the volume fraction of rubber in dry and
swollen samples respectively. Based on Vr value, it has been
observed that, with the exception of silane, all bonding systems
studied improved woodcellulose fibre-natural rubber adhesion.
Optimisation work to determine the optimum level of
resorcinol-hexamethylenetetramine combination was also carried
out based on a statistical factorial experimental design, in
particular the 'central composite design'. Contour graphs of
different properties of compounds for various levels of bonding
agent combination were obtained by means of computer programmes.
From these contour graphs it has been established that the 3 parts
of hexamethylenetetramine (HMT) and 4 parts of resorcinol combination
gives the best overall properties. Mechanical properties of composites containing optimum level
of resorcinol-HMT combination measured in the direction of fibre
orientation have indicated their dependence on fibre concentration.
Young's modulus in particular increases exponentially with
increasing fibre concentration. Experimental and theoretical curves
of Young's modulus versus volume concentration of fibres show good
correlation up to fibre volume concentration of 30%; beyond which
increasing divergence occurred. Besides physical and mechanical properties, the cost factor
of woodcellulose fibre-rubber composite is also considered.
Cost advantage is clearly evident as a result of incorporation of
woodcellulose fibre in natural rubber compound.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Materials
Publisher
© Ku Abd Rahman Ku IsmailPublication date
1983Notes
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.EThOS Persistent ID
uk.bl.ethos.331712Language
- en