Tetrablock Copolymers Based on Oligoether Diols, 2,4-toluene diisocyanate, Isophorone Diisocyanate, and Methylene-bis-о-chloroaniline

Resumo

Tetrablock polyurethane ureas with mixed soft segments and dissimilar hard urethane urea blocks, based on oligo(propylene oxide)diol, oligo(tetramethylene oxide)diol, 2,4-toluene diisocyanate, isophorone diisocyanate, and methylene-bis-o-chloroaniline as a low-molecular-mass chain extender were synthesized and studied. The fragmentary ordering of the polymer chains of the new polyurethane urea was proved by rheokinetic data. The structure–property relationship for the polymer was found. The new polyurethane ureas surpass in the true strength the available diblock polyurethane ureas with poly(propylene oxide) soft segments by a factor of 1.5. The strength properties of the new tetrablock polyurethane ureas only weakly depend on the strain rate varied in the range 0.56–0.006 s^–1.