Abstract:
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Attempts have been made to attain satisfactory
network structures in each of the phases of a rubber blend
by minimising the cure rate imbalance by employing methods
such as grafting of accelerators to the slow curing rubber,
chemically bonding the crosslinking agents to the rubber in
which it has lower solubility, functionalisation of the slow
curing rubber, masterbatching of the curing agents
to the slow curing rubber etc. Functionalisation of
the slow curing constituents of NR/IIR and NR/EIPDM blends
is tried using novel reagents as the first part of this
study. However, the crux of the present study is a more
direct approach to attaining a covulcanized state in NR/IIR
and NR/EPDM blends: Precuring the slow curing rubber (IIR
or EPDM) to a low level when it can still blend with NR and
then to ck) the final curing after blending with NR. TNM3
precuring is also likely to minimise the viscosity mismatch.
Since a low level of resmmal crosslink density is likely to
be present lJ1 reclaimed rubbers, blending heat resistant
reclaimed rubber such as butyl reclaim with NR may also have
the same effect of precuring IIR, and then blending with NR.
Hence use of IIR reclaim for developing blends with NR is
also proposed to be investigated in this study |