TY - JOUR
T1 - Effect of soft-segment CH2/O ratio on morphology and properties of a series of polyurethane elastomers
AU - Martin, Darren J.
AU - Meijs, Gordon F.
AU - Renwick, Gordon M.
AU - Gunatillake, Pathiraja A.
AU - McCarthy, Simon J.
N1 - Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 1996/4/25
Y1 - 1996/4/25
N2 - A series of six thermoplastic polyurethane elastomers were synthesized from a 4,4′-methylene diphenyl diisocyanate (MDI) and 1,4-butanediol (BDO) chain extender, with polyethylene oxide) (PEO), poly(tetramethylene oxide) (PTMO), poly(hexamethylene oxide) (PHMO), poly(octamethylene oxide) (POMO), poly(decamethylene oxide) (PDMO), and poly(1,6-hexyl carbonate)diol (PCDO) macrodiol soft segments. The soft-segment molecular weights employed were similar (approximately 1000 g/mol) and each polyurethane contained 55% (w/w) of the soft-segment macrodiol. Differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), wide-angle X-ray diffraction (WAXD), and Fourier transform infrared spectroscopy (FTIR) techniques were employed to characterize the morphology. Tensile and Shore hardness tests were also performed. Materials were tested in the as-molded, solvent-cast, and annealed states. It was found that the polyurethanes produced from macrodiols with the highest CH2/O ratio displayed greater hard-domain crystallinity, a higher degree of phase separation, and the greatest hardness, stiffness, and opacity. POMO- and PDMO-based polymers displayed evidence of paracrystallinity in the soft domains. The PCDO-based material displayed a higher degree of phase mixing compared to the polyether-based materials. Annealing increased hard-domain crystallinity in all the polyether-based materials. The solvent-cast POMO- and PDMO-based materials had poor mechanical properties and were difficult to cast. The materials containing macrodiols with the lowest CH2/O ratio were more readily solvent-cast and produced strong, useful films. Morphologies of the solvent-cast materials differed greatly from those of the molded materials.
AB - A series of six thermoplastic polyurethane elastomers were synthesized from a 4,4′-methylene diphenyl diisocyanate (MDI) and 1,4-butanediol (BDO) chain extender, with polyethylene oxide) (PEO), poly(tetramethylene oxide) (PTMO), poly(hexamethylene oxide) (PHMO), poly(octamethylene oxide) (POMO), poly(decamethylene oxide) (PDMO), and poly(1,6-hexyl carbonate)diol (PCDO) macrodiol soft segments. The soft-segment molecular weights employed were similar (approximately 1000 g/mol) and each polyurethane contained 55% (w/w) of the soft-segment macrodiol. Differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), wide-angle X-ray diffraction (WAXD), and Fourier transform infrared spectroscopy (FTIR) techniques were employed to characterize the morphology. Tensile and Shore hardness tests were also performed. Materials were tested in the as-molded, solvent-cast, and annealed states. It was found that the polyurethanes produced from macrodiols with the highest CH2/O ratio displayed greater hard-domain crystallinity, a higher degree of phase separation, and the greatest hardness, stiffness, and opacity. POMO- and PDMO-based polymers displayed evidence of paracrystallinity in the soft domains. The PCDO-based material displayed a higher degree of phase mixing compared to the polyether-based materials. Annealing increased hard-domain crystallinity in all the polyether-based materials. The solvent-cast POMO- and PDMO-based materials had poor mechanical properties and were difficult to cast. The materials containing macrodiols with the lowest CH2/O ratio were more readily solvent-cast and produced strong, useful films. Morphologies of the solvent-cast materials differed greatly from those of the molded materials.
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U2 - 10.1002/(SICI)1097-4628(19960425)60:4<557::AID-APP9>3.0.CO;2-N
DO - 10.1002/(SICI)1097-4628(19960425)60:4<557::AID-APP9>3.0.CO;2-N
M3 - Article
AN - SCOPUS:0030125881
SN - 0021-8995
VL - 60
SP - 557
EP - 571
JO - Journal of Applied Polymer Science
JF - Journal of Applied Polymer Science
IS - 4
ER -