Polyethylene mesophase

The generation of an intermediate phase during melting under isometric conditions of orientationally crystallized polyethylene has also been observed56 at temperatures exceeding the melting temperature of ECC. The authors suppose that the mesophase... 

Meesiri, W., Menczel, J., Gaur, U. and Wunderlich, B. Phase transitions in mesophase macro-molecules. III. The transitions in polyethylene terephthalate-co-oxybenzoate). J. Polymer. Sci., Polymer Phys. Ed., 20, 719 (1982)... 

It is worth noting further that, under certain conditions, polymers will also display superheating effects, in which case the mesophase may only appear on heating this can be regarded as "monotropic" behavior in the reversed sense. An example of this in connection with polyethylene will be quoted further below. 

Polyethylene conforms to the situation of Figure la, l.e. under normal conditions it does not display a mesophase, only the familiar orthorhombic crystal form (o). Nevertheless, there exists a virtual mesophase which can be "uncovered" the ways in which this can be achieved is the subject of what follows. 

Figure 6 also displays the connection between the stable hexagonal phase in short n-alkanes and the hexagonal mesophase in polyethylene as a function of chain length in the p-T diagram. A full discussion is given by one of us elsewhere (6). At this place our emphasis is on the continuity, despite the fact that the pressure coefficient of the width of the temperature interval is of opposite sign in these two families of material. This continuity is apparent also by a structural feature, namely the concentration of conforma-... 

Other lyotropic mesophases of amphiphilic block copolymers, such as poly-styrene-h-polyethylene oxide have been used as templates, with the expectation... 

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