Elastomers, analysis Fluorescence

It is of interest to examine the development of the analytical toolbox for rubber deformulation over the last two decades and the role of emerging technologies (Table 2.9). Bayer technology (1981) for the qualitative and quantitative analysis of rubbers and elastomers consisted of a multitechnique approach comprising extraction (Soxhlet, DIN 53 553), wet chemistry (colour reactions, photometry), electrochemistry (polarography, conductometry), various forms of chromatography (PC, GC, off-line PyGC, TLC), spectroscopy (UV, IR, off-line PylR), and microscopy (OM, SEM, TEM, fluorescence) [10]. Reported applications concerned the identification of plasticisers, fatty acids, stabilisers, antioxidants, vulcanisation accelerators, free/total/bound sulfur, minerals and CB. Monsanto (1983) used direct-probe MS for in situ quantitative analysis of additives and rubber and made use of 31P NMR [69]. 

E. Kunkel, Sample preparation of elastomers and other polymers for x-ray fluorescence analysis by borax fusion, A. Anal Chem., 270 126 (1974). 

Details are given of the preparation of blends of bitumen with BR, butyl rubber, polyisobutylene, chlorinated PF, polychloroprene latex, and a PU elastomer. Characterisation was undertaken using fluorescence optical microscopy, DSC, and dynamic mechanical thermal analysis. 18 refs. 

Provorov et al. [520] have studied a rather extensive group of elastomer additives (accelerators, stabilisers, softeners, fillers, and other ingredients) for possible analysis by fluorescence techniques. No fluorescence lifetime measurements have been applied for discriminating stabilisers in polymers. UV microscopy is another means of measuring the concentration (and distribution) of UV absorbing or fluorescent additives in plastics (cfr. Chp. 5.3.2). 

---