Preservation of beech and spruce wood by allyl alcohol-based copolymers

Allyl alcohol (AA), acrylonitrile (AN), methyl methacrylate (MMA), monomers and monomer mixtures AA+AN, AA+MMA were used to conserve and consolidate Beech and Spruce. After impregnation, copolymerisation and polymerisation were accomplished by gamma irradiation. The fine structure of wood+polymer(copolymer) composites was investigated by Scanning Electron Microscopy (SEM). It was observed that copolymer obtained from AA+MMA monomer mixture showed the optimum compatibility. The compressional strength and Brinell Hardness Numbers determined for untreated and treated wood samples indicated that the mechanical strength of wood+copolymer composites was increased. It was found that the mechanical strength of the wood samples containing the AA+MMA copolymer was higher than the others. In the presence of P(AA/MMA), at highest conversion, the compressive strength perpendicular to the fibres in Beech and Spruce increased approximately 100 times. The water uptake capacity of wood+copolymer composites was observed to decrease by more than 50% relative to the original samples, and biodegradation did not take place.     

Chemical reactive filter paper prepared by radiation-induced graft polymerization—I

Chelating filter papers with chemically bonded amidoxime groups were synthesized by radiation-induced grafting of acrylonitrile onto filter paper (W3) followed by chemical treatment with hydroxylamine. The effect of grafting conditions such as absorbed dose, dose rate, monomer concentration and filter paper thickness on the grafting yield was studied. It was found that the degree of grafting increases with increasing absorbed dose and dose rate, and then tends to level off at high doses. The order of the dependence of the initial grafting rate on the dose is found to be of 0.33. An increasing monomer concentration was accompanied by a significant increase in grafting. At high monomer concentration the initial rate of grafting is fast followed by a slow rate. The rate of grafting is controlled by the filter paper thickness and the diffusion of monomer into the interior of the filter paper. Mechanical properties of the prepared filter paper were improved over the ungrafted paper. The amidoxime filter papers were examined for adsorption of uranium concentration ranging between 10–100 ppm.