Polymer degradation and stability vol:92 issue:7 pages:1316-1325
Two series of 4,4'-diphenylmethane diisocyanate (MDI) and poly(ethylene glycol adipate) (PEGA)-based polyurethane and polyurethaneurea elastomers were synthesized via a one-shot polymerization method and characterized using FTIR, H-1 NMR and C-13 NMR. The samples in the first series are extended by aliphatic diol chain extenders while in the second series mixtures of aliphatic diols and furanic or aromatic diamine chain extenders are used. TGA experiments revealed that with furanic or aromatic diamine chain extenders the polymer degradation temperature is shifted 90 degrees C upwards, irrespective of the annealing time at 100 degrees C according to ASTM 0573-99. The values of Young's modulus and of the 9 tensile strength are higher and the strain at break is lower for the samples in series 2 compared to those in series 1. Increasing the annealing time at 100 degrees C lowers Young's modulus. Dynamic mechanical thermal analyses points to a progressive microphase separation with annealing time. (c) 2007 Elsevier Ltd. All rights reserved.