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The thermochemical decomposition of waste products from a coconut (Cocos nucifera L.), a nut (Juglans regia L.) an apricot (Armeniaca vulgaris L.), an almond (Amygdalus communis L. var amara DC.), a grape (Vitis vinifera L.) and a cherry (Prunus avium L.), as raw materials for producing carbon adsorbents, was investigated by DTA and TG. The thermo-oxidative and decomposition processes resulting in increased number of oxygen-containing functional groups of phenolic and carbonyl type are responsible for the high adsorption capacities of the carbon adsorbents. The thermochemical changes in adsorbents based on agricultural wastes are similar to those in commercial activated carbons. The adsorbents derived from apricot stones have the highest overall thermal stability.

SynopsisA study is made of the relationship between the thermal properties of polyurethane elastomers and the efficiencies of antipyrens containing phosphorus and some containing both phosphorus and chlorine. It is shown that a relationship exists between the thermal properties of polyurethane elastomers and the efficiencies of the antipyrens. It is also found that the presence of antipyrens in the molecules of the polyurethane elastomer effects the course of DTA, DTG, and TG curves. This permits antipyren efficiency to be qualitatively evaluated as well as the antipyren optimal concentration to be determined.

The distribution of total oxygen, its forms of binding and geochemical bonds have been studied in Bulgarian Paleogene coals. Various petrographical and chemical analyses have been carried out. The analytical data are quantitatively evaluated by means of statistical, regressional and cluster analyses. The quantitative distribution of the oxygen forms in the coal macromolecule enables the estimation of the coalification processes development. The good correlation between oxygen-containing functional groups and the different macerals suggests that the hydroxyl (phenol), carbonyl and carboxyl groups can be used as genetic indicators. The dependences established between the carbon content, respectively, the reflectance and >CO and -COOH content points that these groups are coalification indicators.