Neoh , Siew Bee
(2010)
Effect Of In-Situ Vulcanization Of
Styrene Modified Natural Rubber In
Adhesive And Rubber Toughened
Polystyrene Applications.
PhD thesis, Universiti Sains Malaysia.
Abstract
In this research, establishment of vulcanization formulation of styrene modified natural
rubber ( SNR ) vulcanizates by using in situ vulcanization technique was investigate. The
synthesis of SNR was prepared through emulsion polymerization. Deproteinized natural
rubber latex (DPNR) was grafted with styrene monomer with the addition of ammonium
persulfate as initiator. SNR vulcanizate was prepared with different vulcanization
methods and vulcanization agents. The first stage of the work involved in established the
emulsion polymerization of SNR with ratio of styrene monomer and DPNR ratio 25%:
75%. For adhesive application, the effect of three pre-vulcanization systems,
conventional vulcanization (CV), semi-efficient vulcanization (semi-EV), and efficient
vulcanization (EV) on tensile properties of SNR pre-vulcanizates were observed. The
semi-EV vulcanization system showed suitable properties as SNR pre-vulcanizates
adhesives. It showed similar trend in elongation at break (EB) compared to CV system
with low tensile strength (TS). The effect of pH modification on semi-EV pre-vulcanized
system showed the SNR with good anchorage ability at pH 12 suitable for adhesive
application. For rubber toughened material application, in situ vulcanization process with
sulfur as crosslinking agent had improved the impact strength of the PS/ SNR
vulcanizates.
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