Sunil,K Narayanankutty(Taylor & Francis Inc., August 23, 2004)
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Abstract:
The rheological characteristics of short Nylon-6 fiber-reinforced Styrene
Butadiene rubber (SBR) in the presence of epoxy resin-based bonding agent were
studied with respect to the effect of shear rate, fiber concentration , and temperature
on shear viscosity and die swell using a capillary rheonzeter. All the composites
containing bonding agent showed a pseudoplastic nature, which decreased
with increasing temperature. Shear viscosity was increased in the presence of
fibers. The temperature sensitivity of the SBR matrices was reduced on introduction
of fibers. The temperature sensitivity of the melts was found to be lower at
higher shear rates. Die swell was reduced in the presence of fibers. Relative viscosity
of the composites increased with shear rate. In the presence of epoxy resin
bonding agent the temperature sensitivity of the mixes increased. Die swell was
larger in the presence of bonding agent.
Sunil,K Narayanankutty(Sage Publications, April , 2002)
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Abstract:
Acrylonitrile butadiene rubber (NBR) matrix was reinforced with
different levels of short nylon fiber loading. Cure characteristics and mechanical
properties of composites in longitudinal and transverse directions have been
studied. Cure time was reduced while processability, as indicated by the
minimum torque, was marginally reduced with increase in fiber loading. Tensile
and tear properties improved with fiber concentration and the values were
higher in longitudinal direction of fiber orientation. Abrasion resistance,
resilience and compression set were increased in presence of fibers. Elongation
at break values showed a drastic drop on introduction of fibers. Heat build up
was higher for composites.
The cure characteristics of short fiber-polyurethane elastomer
were studied with respect to different fiber-matrix bonding agents. A hexamethylenetetramine-
resorcinol -hydrated silica based bonding agent was found to affect
the stability of the composite. A new bonding agent, TP resin, based on polymeric
toluenediisocyanate and polypropylene glycol has been developed. Cure characteristics
of the composite with and without TP resin at different fiber loadings were
also compared. Minimum torque, scorch time and optimum cure time increased
with fiber content. Maximum torque was consistently higher with TP resin at all
fiber loadings.