Identification of defect chain motions in the low temperature orthorhombic phase of binary mixtures of n-alkanes by means of nuclear magnetic resonance spin-lattice relaxation time measurements

Powder x-ray diffraction, differential scanning calorimetry, and nuclear magnetic resonance spin-lattice relaxation time measurements on a series of n-alkane binary mixtures are reported. The results have been interpreted in terms of a model in which the longer chains execute thermally activated end-gauche defect motions, while the shorter chains are involved in twofold screw motions. The results are compared with infrared and x-ray diffraction results.