This book deals with the application of spectroscopic techniques for characterisation of chemical and physical structures in viscoelastic materials, such as unvulcanised elastomers and their vulcanisates, various rubbery materials and some plastics, which when blended with particular additives (plasticisers) behave like rubbers. Analysis of the rubbery materials is complicated by the fact that rubbery products, such as tyres, tubes, seals, V-belts and hoses, contain in the rubbery matrix a significant amount of various compounds, i.e., fillers, vulcanising agents, antioxidants and plasticisers.