Deformation of microphase structures in segmented polyurethanes

Simultaneous small-angle X-ray scattering/wide-angle X-ray diffraction study of the microdomain structure of polyurethane elastomers during mechanical deformation

“…[24][25][26][27][28] However, the deformation behavior of the PUE is still not well understood because a tremendous number of factors need to be considered to control the original phase structure. Systematic sample preparation and mechanical measurements for the samples would give us a general interpretation on this topic.…”

Small angle x-ray study of the deformation of 4,4'-diphenylmethane dilsocyanate1, 4'-butanediol (MDIBDO) based polyurethanes

“…The polyurethanes were supplied in the form of melt pressed sheets 15 In figure 9b at higher magnification the larger deformation has caused the crazes to open up and the internal structure can be seen to consist of fibrils running perpendicular to the craze boundaries (parallel to the deformation direction)…”

“…Crazes have been observed at elongations close to failure in all three polyurethanes studied so far, yet the presence of crazing has not been recognized in the scientific literature as being important Small angle x-ray scattering of polyurethanes has been studied by numerous authors [1,7,8,[12][13][14][15][16][17] but only a relatively small number of these were concerned with morphology changes that occurred with deformation [15][16][17].…”

Phase segregation and viscoelastic behavior of poly(ether urethane urea)s

“…proach to the problem, using SAXS. 9 They found The values of log(t 1/2 /t 0 ) indicate the PTMGthat, when stretching amine-cured polyurebased copolymer as the more phase-segregated, if thanes, hard segments lamellae tilted away from one has in mind Sung and Smith's criteria 10 (the the stretch direction, while the soft-segment milonger t 1/2 , the higher the phase segregation will crophase deformed in the shear. The reversibility be).…”

“…8 Their work, in conjunction with the sulting from the strong cohesion of the hard work of Desper et al on the characterization of phase. microstructure deformation of polyurethanes by Moreland et al extensively studied the visco-SAXS, 9 constitutes a comprehensive study on the elastic behavior of polyurethane foams as a funcmechanisms of deformation and relaxation of tion of temperature and relative humidity.…”