RADIATION CHEMICAL REACTIONS IN ORGANIC SYSTEMS: REACTIONS ON MACROMOLECULAR SUBSTANCES AND THE SULFINATION OF HYDROCARBONS

Technical Report · Sat Oct 31 04:00:00 EST 1959

OSTI ID:4269329

Henglein, A; Heine, K

Graft polymers by gamma radiation. Upon irradiation of a polymer in the presence of a vinyl compound by gamma rays free, macro-radicals resulting from the decoraposition of the polymer initiate the polymerization of the monomer. Systems investigated comprised 3 components. A definite form of a polymer dips into an inert'' fluid having no swelling or dissolving capacity for the polymer. The monomer vinyl compound is dissolved in the fluid in an adequate concentration. Before irradiation the vinyl compound slowly diffuses into the polymer. Because the gamma rays affect the whole system, those parts of the polymer are grafted which contain the infiltrated monomer. Furthermore, homo-polymerization of the monomer in the solution tekes place. Depending on the diffusion before irradiation, there results a grafting of the surfate layer of the polymer (surface grafting) or a grafting extending to the interior of the polymer (bulk or total grafting). Oxygen cancels the homo-polymerization in the solution. Oxygen diffuses from the solution into the polymer and inhibits polymerization in a thin layer just under the surface. In this case, grafting is effected in a layer in the interior of the polymer (imbedded grafting). The kinetics of these different graft processes was studied for several systems and the properties of the resulting products were investigated. Degradation and cross-linking of macromolecules in solution: For the degradation by gamma rays of the main chain of polymethylmethacrylate, different mechanisms are operative: direct and indirect radiation effects and energy transfer between excited states of the polymer and of the solvent. The prevailing mechanism depends on the solvent. The degradution may be essentially decreased either by defined mixtures of solvents or by the addition of certain compounds in very small concentration. Polystyrene in solution undergoes at the same time a degradation of the main chain and an intermolecular cross-linking. With increasing concentration of the polymer, the cross-linking increases at a higher rate than the degradation. Cross-linking depends on the solvent, i.e., bad'' solvents give an improved crosslinking and vice versa. Even small amounts of substances known as inhibitors for radical chain polymerizations suppress cross-linking of polystyrene. Sulfination of organic compounds: Organic substances undergo reactions with sulfur dioxide under the influence of gamma rays and high-energy electrons. Hydrocarbons, for instance, form sulfonic and sulfinic acids, sulfones, and sulfoxides. G-values for several substances undergoing reaction with sulfur dioxide were determined and also the quantities of the resulting compounds. (auth)

• Research Organization: Univ. of Cologne
• NSA Number: NSA-13-006438
• OSTI ID: 4269329
• Report Number(s): A/CONF.15/P/962
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACRYLATES-- ACRYLIC ACID-- CATALYSIS-- CHEMICAL REACTIONS-- CRYSTALS-- EXCITATION- - FREE RADICALS-- GAMMA RADIATION-- IRRADIATION-- LATTICES-- MEASURED VALUES-- METHYL RADICALS-- MIXING-- MOLECULES-- ORGANIC COMPOUNDS-- POLYESTERS-- POLYMERS-- POLYSTYRENE-- QUANTITY RATIO-- RADIATION CHEMISTRY-- RADIATION EFFECTS-- REACTION KINETICS-- SOLVENTS-- TABLES-- THERMODYNAMICS-- TRACE AMOUNTS
CHEMICAL REACTIONS-- DECOMPOSITION-- DIFFUSION-- EXPANSION-- FILMS-- FREE RADICALS-- GAMMA RADIATION-- IRRADIATION-- MEASURED VALUES-- MOLECULES-- ORGANIC COMPOUNDS-- OXYGEN-- POLYMERIZATION-- POLYMERS-- QUANTITY RATIO-- RADIATION CHEMISTRY-- RADIATION EFFECTS
CHEMISTRY