Indexed on: 01 Jan '95Published on: 01 Jan '95Published in: Journal of Materials Science
Two poly (tetramethylene glycols) (PTMG), molecular weight of 650 and 2000, with 4,4′-diphenylmethane diisocyanate (MDI) and poly(4, 4′-diphenylsulphone terephthalamide) (PSA) prepolymer were polycondensated. Four different molar ratios of PTMG, MDI and PSA prepolymer were synthesized to form eight PU-PSA block copolymers. The mechanical properties including stress-strain and stress-relaxation measurements of each copolymer were discussed. The determined values of Young's modulus E, Mooney-Rivlin relation elastic parameters C1 and C2, relaxation moduli E1(0) and E2(0), relaxation time τ1 and τ2 were used to estimate the effect of hard segment and soft segment domains on the mechanical behaviour of copolymers. It was found that PU-PSA block copolymers apparently displayed elastic properties, especially using the molecular weight 2000 of PTMG which exhibited more elastic behaviour.