Ethylene-octene copolymers peak melting temperatures

Figure 19 (a) Peak melting temperature as a function of the branch content in ethylene-octene copolymers (labelled -O, and symbol —B (symbol, ) and -P (symbol, A) are for ethylene-butene and ethylene-propylene copolymers, respectively) and obtained from homogeneous metallocene catalysts show a linear profile, (b) Ziegler-Natta ethylene-octene copolymers do not show a linear relationship between peak melting point and branch content [125]. Reproduced from Kim and Phillips [125]. Reprinted with permission of John Wiley Sons, Inc. 

Kolesov and Radusch prepared peroxide cross-linked binary and ternary blend SMPs from high density polyethylene and two ethylene-l-octene copolymers with medium and high degrees of branching [47]. The blends were prepared by a melt mixing and subsequently are cross-linked with 2 wt% of liquid peroxide 2,5-dimethyl-2,5-di-(tertbutylperoxy)-hexane at 190°C. The blends showed multiple shape memory behavior that appeared only at consequent stepwise application of convenient programming strains and temperatures. Obviously, that is caused by multiple melting behavior of these blends with many poorly separated peaks. 

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