Theoretical and Experimental Substantiation of the Nature of Interaction between Modified Binders and Wood
Journal Title: Lesnoy Zhurnal (Russian Forestry Journal) - Year 2022, Vol 10, Issue 6
Abstract
There are numerous methods for analyzing surface phenomena when bonding wood materials, mutual arrangement of pores in the wood substrate, and depth of liquid adhesive penetration into wood. Electron microscopic methods such as atomic force and scanning tunneling microscopy are used along with optical methods. They allow evaluating the influence of factors describing the interaction between the liquid adhesive molecules and the porous wood surface. Phenol formaldehyde resin modified with pectol and urea formaldehyde resin modified with lignosulfonates were used for substantiation of the interaction mechanism between modified adhesives and wood. Electron microscopy was used to study the depth of adhesive penetration into veneer. The plywood was produced using modified urea and phenol formaldehyde adhesives. After conditioning, samples with a thickness of 0.025 mm were cut out and examined with a scanning electron microscope. The article shows that the interaction between liquid phenol formaldehyde adhesive modified with pectol and wood results in a sequential increase in the molecular weight of the substances and, consequently, in the penetration degree (depth). The studied wood species (birch, pine and larch) and modified thermosetting urea and phenol formaldehyde adhesives are polar materials (adhesive interacts with wood molecules with the formation of intermolecular bonds, including hydrogen bonds). The molecular weight growth and the freely joined nature of the main chain (liquid modified adhesive macromolecules), which contains a large number of polar functional groups (adhesive and wood), promote intermolecular association. The formation of an adhesive bond between urea formaldehyde adhesive modified with lignosulfonates and wood occurs due to chemical interaction between hydroxyl groups of cellulose macromolecules and methoxyl groups of urea resin with the formation of esters (hydrogen atoms of hydroxyl groups OH are substituted with hydrocarbon radicals R). The formation of a bond between the adhesive and the wood surface is the result of molecular interaction forces at the liquid adhesive – wood interface, when the distance between molecules of the same polarity (adhesive and wood) is less than 0.5 nm. Then, adsorption equilibrium sets in. For citation: Rusakov D.S., Varankina G.S., Chubinsky A.N. Theoretical and Experimental Substantiation of the Nature of Interaction between Modified Binders and Wood. Lesnoy Zhurnal = Russian Forestry Journal, 2022, no. 6, pp. 153–163. (In Russ.). https://doi.org/10.37482/0536-1036-2022-6-153-163
Authors and Affiliations
Dmitry S. Rusakov Saint-Petersburg State Forest Technical University named after S. M. Kirov https://orcid. org/0000-0002-4344-2779 Galina S. Varankina Saint-Petersburg State Forest Technical University named after S. M. Kirov https://orcid. org/0000-0003-3470-5124 Anatoly N. Chubinsky Saint-Petersburg State Forest Technical University named after S. M. Kirov https://orcid. org/0000-0001-7914-8056
Keywords
Related Articles
- EP ID EP711807
- DOI 10.37482/0536-1036-2022-6-153-163
- Views 88
- Downloads 0
Photosynthesis, Mineral Nutrition and Productivity of Decidious and Coniferous Dendroflora Species in the Central Part of the Russian Plain
An ecological and physiological retrospective transformation of the data from the dry mass tables obtained by V.A. Usoltsev has been carried out for 7 coniferous and deciduous species (Larix sukaczewii, Picea abies, Pinu...
Winter Hardiness of Conifers in the Northern Forest Steppe Conditions of the South of the Tyumen Region
We have studied 4 species of the genus fir, 3 species of the genus spruce (including (hereinafter) 14 varieties of Norway spruce and 12 varieties of blue spruce), 2 species of the genus larch (3 varieties of Western Euro...
The Current State of Conifer Species Breeding and Seed Production
The article analyzes and summarizes information on breeding and seed production of the main forest-forming and commercial species for the countries of Northern Europe and Russia: Scots pine (Pinus sylvestris L.) and Norw...
Formation of Adsorption Properties of Carbon Nanostructured Materials by Thermochemical Activation of Sludge-Lignin
Pyrolysis is an effective way to process waste of the pulp and paper industry, in particular, sludge-lignin, which makes it possible to obtain a commercial product – a carbon adsorbent. The method of thermochemical activ...
Seasonal Dynamics of Content of Antioxidant System Component in Needles of Scots Pine (Pinus sylvestris L.) Trees Situated in the Local Warming Impact Zone
The seasonal changes in a period of low temperatures and characteristic correlations of some antioxidant system (AOS) components in pine needles influenced by a gas flare are investigated in this study. The parameters ta...