Evidence of intra-chain phase separation in molten short-chain branched polyethylene
F. J. Stadler
Vol. 5., No.4., Pages 327-341, 2011
DOI: 10.3144/expresspolymlett.2011.33
DOI: 10.3144/expresspolymlett.2011.33
GRAPHICAL ABSTRACT
ABSTRACT
Intramolecular phase separation is usually associated with block-copolymers, but the same phenomenon is also obtainable by random-copolymers. In this article, evidence of intramolecular phase separation is reported for a linear octadecene-ethene copolymer, which shows an evolving 'yield point' at a long time and low frequency. This is attributed to a partial phase separation of the long short-chain branches. In creep recovery, this behavior is evident as increasing elastic steady-state creep recovery compliance Je
0. In contrast to 'normal' block-copolymers, this special polymer has an increase in phase separation with temperature, which is caused by the chemical composition and the short chain segments in the side chain domain, leading to a high surface fraction.