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Gremmeniella abietina damage was studied at stand and tree level on the Kola Peninsula and in northern Finland. At stand level, damage was recorded in four areas in Finland, while only individual damaged trees were found in Russia. According to the results of branch analysis, there was no sign of endemic epidemics in any of the areas. There was a significant negative correlation between the average G. abietina damage and modelled SO, deposition and temperature sum along the gradient. The results suggest that G. abictina is distributed all over northern Finland and the Kola Peninsula in natural' stands of Scots pine, and that the direct effect of SO2 deposition from the Monchegorsk nickel smelter on the damage may be minimal.

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The article presents the results of research in the field of processing wood and thermopolymer waste to produce new high-performance compounds, which may be used in the production of composite railroad ties.

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The problem of reducing the toxicity of binders in the production of wood plate materials remains urgent and requires comprehensive solutions. In this work, we used a way of improving the quality of products that consists in the formation of adhesive joints from oligo meric compounds. The essence of this method is to pro vide a gradient of properties in a given direction, which is achieved by applying so called interpenetrating net works formed by the combination of two oligomers in a liquid state [1]. Transition into a two phase state with subsequent solidification is accompanied by increased strength and other physical and mechanical properties. Glued joints formed from such oligomeric mixtures have fewer internal stresses, since the thermoplastic fraction, which has a low modulus of elasticity, pro motes the dissipation of internal stresses.According to the results of preliminary studies, polyvinyl acetate dispersion (mass fraction of nonvol atile substance is at least 30%, the viscosity of the adhesive according to the VMS (GOST 18992-80)-35 s) standard mug was selected as a modifying addi tive, plasticized with a mixture of polyfunctional com pounds containing oxygen containing cycleshydroxyl and ester groups.Carbamide-polyvinyl acetate glue-the binding agent-was prepared by mixing KF MT 15 urea resin grades (dry matter content of 65%, free formaldehyde content of 0.14%) and an aqueous dispersion of polyvinyl acetate. This adhesive has a satisfactory viscosity, rather high viability, and good adhesive properties. Compounds on carbamide-polyvinyl acetate adhesives have high strength characteristics and have almost no disadvantages of the compounds in urea and polyvinyl acetate adhesives. Figures 1 and 2 show the properties of the compo sitions obtained in the ratio of the components UF : PVA = variance from 100 : 0 to 100 : 50 wt %. Abstract-The technological properties of urea formaldehyde resins modified by polyvinylacetate are pre sented. 54 50 44 40 50 40 30 10 0 20 Viscosity, s Amount of modifier, wt % 42 46 48 52 56 Fig. 1. Influence of the amount of the modifier on the viscosity of the urea formaldehyde binding agent. 9.0 8..5 8.0 7.5 7.0 50 40 30 10 0 20 pH Amount of modifier, wt % Fig. 2. Influence of the amount of the modifier on the pH of the urea formaldehyde binding agent.

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