Applications of Ultraviolet Spectrography a Study of the Transformations of Tetramethylthiuram Disulfide When It Functions as a Direct Vulcanizing Agent
In addition to sulfur, which is the most common vulcanizing agent, rubber mixtures usually contain various kinds of accessory ingredients, both inorganic and organic. Among the organic ingredients, some, notably accelerators and antioxidants, are present in relatively small proportions, and these are susceptible to transformation during vulcanization. However, only in rare cases has it been possible to isolate in definite form the products of these transformations, and consequently it is difficult to interpret the part played by these substances during vulcanization. Since, with few exceptions, each accelerator and each antioxidant has its own characteristic absorption spectrum in the ultraviolet region, spectrography constitutes in general an important method for following the behavior of accelerators and antioxidants. This method has been demonstrated by Dufraisse and Houpillart, who have developed a special technique for obtaining ultraviolet absorption spectra and examining them, frequently with interesting conclusions to be drawn from such analyses.