Polyurethane elastomers (PUEs) were prepared with poly(oxytetramethylene) glycol (M n ¼2000), 4,4¢-diphenylmethane diisocyanate, 1,4-butanediol (BD) and 1,1,1-trimethylol propane (TMP) by a prepolymer method. To evaluate the effect of curing temperature and the ratio of curing and crosslinking agents ((BD/TMP)¼(10/0 and 8/2)(wt/wt)) on deformation behavior, four different samples were prepared. In the small-angle X-ray scattering (SAXS) profile for the PUEs prepared at 120 1C, a four-point pattern was observed with the preferred tilt being produced by local torques exerted within the strained soft segments from the initial deformation. At near failure strains, strong meridional scattering appeared and the four-point pattern disappeared. In contrast, the PUEs at 80 1C produced meridional scattering through the deformation. As the microdomain structure of the PUEs prepared at 120 and 80 1C initially possessed cylinder-and sphere-like structures, respectively, the cylinder-like structure might have produced the four-point pattern. Obvious changes in interdomain spacing of PUEs at 120 1C during the deformation process were observed in comparison with the spacing at 80 1C. This was due mainly to the formation of a well-developed, networked, cylinder-like microdomain structure. Strain-induced crystallization of the soft-segment chains evaluated by wide-angle X-ray diffraction results was also consistent with the results from SAXS.

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This paper presents a comparison study of various motors for application to an electric vehicle (EV) and the potentiality of a ferrite magnet motor as a candidate for rare-earth-less motor for an EV. The rotor shape of the proposed ferrite magnet motor is based on a spoke-type shape. Further, we developed two types of prototypes: one has a large magnetic torque equivalent to a conventional rare-earth permanent magnet motor for an equal volume, and another has a wide variable-speed range suitable for an EV.