Infrared spectroscopic studies of ultrathin microtomed sections of polymers. Part I. Characterization and structure determinations of cured, black-loaded rubbers

Previous time-consuming, destructive methods for examination of infrared spectra of cured, black-loaded rubbers have been replaced almost entirely by a rapid new technique which examines the rubber in its original form. By use of ultrathin microtomed sections (ca. 2 μ thick) of the rubber and electrical amplification of the absorptions on a recorder quite good infrared spectra of the rubber may be obtained. Characterization and structure determination of the rubber can then be carried out. Many different polymers, copolymers, and mixtures of polymers which have been loaded with up to 60 parts phr of carbon black and cured have been characterized in this way. Typical applications to determinations of polymers in tires, etc. are described. The effect of variation in particle size of carbon black is considered.