Abstract
Three methods have been discussed which have been successfully used for the degradation of vulcanizates for infrared analysis: pyrolysis between 450 and 600°C, degradation in 1,2-dichlorobenzene, and incomplete degradation at 200°C. Because of the relatively low cost, pyrolysis is generally used for the identification of single elastomers, but this method is less suited to blends where it may lead to the loss of ir bands characteristic of a certain component, e.g. polybutadiene. It is similarly unsuited when polymers which form mostly gaseous components are present in small amounts. Since it cannot be excluded in the analysis of vulcanizates of unknown composition, it is recommended to confirm the identification by partial decomposition at 200°C. Because of its greater cost, degradation in 1,2-dichlorobenzene is preferred only for vulcanizates containing small proportions of thermally stable rubbers. When one operates in this way, it is safe to assume that no polymer components will be missed which constitute more than 20 wt % of a rubber blend. Below this limit, identification depends greatly on the components of the blend.
Green and Low-cost Production of Thermally Stable and Carboxylated Cellulose Nanocrystals and Nanofibrils Using Highly Recyclable Dicarboxylic Acids