Melting of nascent superhigh-molecular-weight poly(ethylene oxide) obtained by means of heterogenous ion-coordinate polymerization

Melting of nascent and thermally treated super-high molecular weight polyethylene

“…Some of our studies have confirmed this analogy; in the studied PE, as well as in strongly deformed fibres of super-high molecular weight PE [14], a monoclinic modification has been observed [33,34]. Similar properties have also been found for super-high molecular weight nascent PEO [7][8][9], in which a transition to a triclinic lattice typical for strongly oriented PEO has been observed with inceasing temperature [35]. All this suggests that the reasons for the similarity in properties should be sought not in the mutual orientation of the macromolecules but in the macroconformation similarity of separate molecules in oriented and nascent polymers.…”

“…As shown in our previous studies [8,10], the point of entanglement in the tie segments of strongly entangled long molecules are retained even after melting. This leads to an enhanced concentration of entanglements in the melt.…”

“…The literature data have been reviewed elsewhere [8] and these data prove or can be explained in terms of the presence of a net of numerous tie molecular segments. The following data should be added to the above:…”

“…The problem of the physical essence of this additional effect has not been discussed [4,5]. K 861 Similar properties are displayed also by the nascent super-high molecular weight poly(ethylene oxide) (PEO) (My = 1 x 10 6 tO 7 x 10 6) prepared by heterogeneous ion-coordination polymerization [6][7][8][9][10]. A well expressed dependence between the structure and the thermodynamic parameters of melting (melting temperature Tin, enthalpy of melting AHm, Vm) has been found.…”

“…A well expressed dependence between the structure and the thermodynamic parameters of melting (melting temperature Tin, enthalpy of melting AHm, Vm) has been found. The high temperatures and enthalpy of melting and their dependence on the temperature of the previous thermal treatment have been explained [8,9]. Thus during the polymerization process a net of entangled tie molecules is thought to be formed [6].…”