THE EFFECT OF INTRAMOLECULAR ORDER IN BLOCK COPOYURETHANE ELASTOMERS I. STRESS-STRAIN, STRESS RELAXATION AND THE ENERGY LOSS

摘要

The characterisation of different classical and novel polyurethane elastomers (PU) as block copolymers consisting of blocks of different mechanical/physical and chemical properties was achieved. The correlation between the PU properties and the chemical structure of the constituent polymer blocks was followed. The effect of the molecular induced structural ordering on the mechanical properties of polyurethane elastomers hesis routes were approached. The stress-strain behaviour, stress relaxation and the energy loss is discussed both for PU with an usual quasi ordered structure and for novel PU based on specific hard segments with conformational mobility for which an enhanced sequential ordering of was approached.