Optimization of the precision and accuracy of methods for the determination of chloroprene rubber (CR) in complex elastomer blends and technical elastomeric materials

Abstract

The Instrumental Analysis and Polymer Characterization group (IAPC) in Merseburg is specialized in the characterization of physical and chemical properties of polymers. Technical elastomers are characterized by the polymer composition and the additives used. For chloroprene rubber (CR), it is difficult to determine quantitatively the polymer-related CR content by pyrolysis GC/MS due to its inaccurate and time-consuming nature. The goal of this thesis is to combine the Schöniger digestion (SD) with Thermo gravimetric analysis (TGA) in order to determine the CR content in an elastomeric mixture. The SD is an oxidation method used for determining the presence of chloride. The SD had to be optimized in order to accelerate the method and realise high yields of chloride. The second method, TGA, was used for the determination of the rubber amount in an elastomeric mixture. TGA was executed on pure samples and elastomeric mixtures to determine the decay steps for each material. A mathematical formula was calculated for binary and ternary elastomeric mixtures. The results were successful. The Schöniger digestion was accelerated 2.4 times and a high yield of chloride was realized. The calculated formula from the TGA measurements had an overshoot but the results show that there is correlation between the measured and calculated values. After comparison with Pyrolysis GC/MS, results concluded that it is possible to use the combined method for an accurate CR determination.