Structural-Dynamic Characteristics of the Nonwoven Materials and Films Based on Polyurethane, the Styrene-Acrylonitrile Copolymer, and Their Blends
ESR method and DSC calorimetry method were applied for investigation films and nonwoven materials. For PU and styrene-acrylonitrile copolymers fibers it is shown that a solvent weakly affects the molecular dynamics of chains in the film and nonwoven polyurethane materials and has a strong effect on the molecular mobility in the films based on the styrene-acrylonitrile copolymers and blends with a high content of the copolymer. For the nonwoven material, this effect is insignificant. Breaks at the melting temperatures of mesomorphic structures in PU- styrene-acrylonitrile blends were revealed from the dependence of correlation time on temperature and polymer ratio. The influence of ozone on the amorphous phase of this polymers was studied and it was shown by the spin-probe method that for PU-based films and nonwoven materials ozone has no effect on the molecular dynamics, where as for blends and styrene-acrylonitrile copolymer considerable changes in τ take place.