| Popis: |
Previously, it has been shown that polycondensates can be synthesized from non-symmetric monomers (XabX) and symmetric monomers (YccY), giving rise to a constitutional isomerism similar to the head/tail isomerism exhibited by vinyl polymers. This constitutional isomerism in polycondensates can be controlled in a predeterminable and continuous manner over a wide range of constitutional order. The order parameter's is quantified by the probability that two adjacent non-symmetric monomeric units are oriented in the same direction relative to the molecular axis. Constitutional isomerism has a profound effect on the properties of polyamides, partly because more constitutionally regular polyamides yield solids of higher three dimensional order than their more irregular counterparts; packing efficiency and crystallinity are direct functions of order. Polyamides; Reprints. |
