Investigation of the Relaxation Spectrum of Multi-component Systems by Pulsed NMR Part 1 Establishment of the Relaxation-spectrum Analyzing Method

Abstract

Pulsed NMR is ananalytical method that can detect molecular mobility of multi-component system. Because it is possible to separate the relaxation behavior of the each component quantitatively, it has been used to analyze the phase structure and the characteristics of the pressure sensitive adhesives. Although the measured macroscopic magnetization M(t) was data with plenty of chemical and physical information, the information have not been fully analyzed by conventional, commercially availablesoftware. By the improvement in performance of personal computers and the development of the numerical processing algorithm, a program to obtain relaxation spectra by numerical differentiation of the macroscopic magnetization M(t) was created. The relaxation spectra have much amount ofinformation on molecular mobility of polymers, compared with conventional T2 relaxationtime. Therelaxation spectra of pressure sensitive adhesives composed of SIS/tackifier system were obtained using the program. The elucidation of the interaction of a polymer and a tackifier became clear from the relaxation spectrum. The analysis using the relaxation spectra is a very useful method to lead the molecular design and the formulation of pressure-sensitive-adhesives.