title: Morphology of block copolyurethanes: V. The effect of -CH2CH2- vs -CH2- spacers between aromatic rings.
abstract: Copolyether-urethane-ureas based on 1,2-ethylene bis(4-phenylisocyanate), polypropylene glycol and ethylene diamine were synthesized by both the standard two-step and a multi-step procedure and their properties compared with analogous copolyurethanes based on methylene bis(4-phenylisocyanate). The infrared and dynamic mechanical properties indicate differences in the packing structure of the hard domains between these two copolymer systems. The infrared data suggest that the introduction of a -CH2CH2- spacer between the two aromatic rings of the diisocyanate results in a coplanar packing in the hard domains for these copolyurethanes.
authors.affiliation: Department of Bioengineering, University of Utah, Salt Lake City 84112.
authors.forename: L A
authors.initials: LA
authors.lastname: Gower
authors.forename: T L
authors.initials: TL
authors.lastname: Wang
authors.forename: D J
authors.initials: DJ
authors.lastname: Lyman
mesh_terms: D001696:Biomechanical Phenomena; D002942:Circular Dichroism; D011140:Polyurethanes / Q000138:chemical synthesis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
chemical_list: D011140:Polyurethanes