C. Daniello et al., CORRELATION BETWEEN MICROSTRUCTURE AND PHYSICAL-PROPERTIES IN STYRENEETHYLENE COPOLYMERS, Journal of applied polymer science, 58(10), 1995, pp. 1701-1706
The structural organization and the physical properties of a new copol
ymer styrene-ethylene have been analyzed. The composition was 80% of e
thylene units, corresponding to 52% in weight, with a distribution of
styrene units in the chain implying the absence of styrene-styrene seq
uences. The length of the polyethylene chains, limited by the insertio
n of the phenyl group, is not sufficient to allow good crystallization
, and in fact the copolymer shows a very low crystallinity, of the ord
er of 5-10%, and a broad melting range, with a peak centered at 120 de
grees C. The small crystalline domains are segregated into an amorphou
s matrix, producing a thermoplastic elastomer. The mechanical properti
es at large deformation were analyzed at different temperatures. The c
opolymer shows good elastic properties, in terms of deformation revers
ibility as well as of energy dissipation in the hysteresis cycles. Als
o the stress level and the elastic recovery are very good, if compared
with others thermoplastic elastomers. (C) 1995 John Wiley & Sons, Inc
.