Accession Number : ADA193538

Title :   Hierarchical Structure in Polymeric Solids and Its Influence on Properties.

Descriptive Note : Research rept. no. 6, Sep 87-Mar 88,

Corporate Author : BRISTOL UNIV (ENGLAND)

Personal Author(s) : Keller, A

PDF Url : ADA193538

Report Date : Mar 1988

Pagination or Media Count : 22

Abstract : Of the variety of avenues arising from our preceding investigations of Professor Percec's (Cleveland) specially synthetized mesogenic polyethenes, currently we pursued the aspect of non-equilibrium liquid crystal deficiency ( degree of (non-equilibrium) liquid crystallinity ) and its perfectioning on heat treatments. We established and compared the effect of heat treatments both when annealed while in the liquid crystalline and in the crystalline solid state with numerous implications arising. We investigated effects related to non-equilibrium liquid crystal deficiency as a function of chain flexibility and molecular weight (M). We observed, amongst others, that increased flexibility reduces this deficiency and promotes perfectioning when such deficiency is present, while decreasing flexibility and increasing M has the opposite effect with the outcome that variability of degree of liquid crystallinity , as normally observed, is most pronounced at intermediate flexibilities and molecular weights.

Descriptors :   *POLYMERS, *SOLIDS, *ETHANES, CRYSTALS, DEFICIENCIES, HEAT TREATMENT, HIERARCHIES, LIQUID CRYSTALS, LIQUIDS, MOLECULAR WEIGHT, NONEQUILIBRIUM FLOW

Subject Categories : Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE