Международный научно-образовательный электронный журнал «образование и наука в XXI веке»

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wakiephysico-mechanical properties of the product and waveny dependence of the 
modifier-free formaldehyde. Obtained wood boards completely meet the requirements 
of the standard predevlyaemye to the plates. 
The main physical and mechanical 
properties of particle boards are water absorption, swelling, ultimate strength in static 
bending and ultimate strength in fracture perpendicular to the layer. These indicators 
of the properties of the boards largely depend on the quality and properties of the binder 
polymer, on its degree of curing during the production of boards.To obtain particle 
boards, the following types of work were performed: Preparation of gossypol resin by 
dissolving it in white spirit in a 1: 1 ratio. The wood was crushed to a length of 2-3 cm 
and a width of 0.2-0.4 cm. The accepted dimension of chips was determined according 
to GOST for chips used for the production of board materials. The total amount of 
binder used was 10% of absolutely dry chips. The binder modification was carried out 
at a temperature of 60 ° C and a modification time of 180 minutes. Binder concentration 
KF-MT-63%. Pressing temperature - 170 ° C, pressing time - 0.30 mm / min, plate 
thickness 1.60 ± 1 cm, pressure - 2.5 MPa.
The study of the effect 
of gossypol resin on the physicochemical urea-formaldehyde binder showed that the 
modifier has a positive effect on all its properties, such as hydrophobicity, heat 
resistance, adizability, etc. Now it was necessary to conduct research on a specific 
product, where different results could be obtained.
In this work, it was necessary to compare the 
results of studying the effect of the content of the modifier in the binder on the physical 
and mechanical properties of the plates, i.e. the results of experiments with a binder 
were transferred to the finished product - chipboard. 
To determine the amount of gossypol resin, it was introduced 
in an amount of 0.5%; 10%; 15%, 20%; 30% of the dry residue of the resin to determine 
the optimal content. As the results of the study showed, the introduction of the modifier 
affects the quality of the slab, where the ultimate strength in static bending showed 
that, in comparison with the unmodified composition, in specimens with gossypol resin 
the flexural strength increased from 13.3 MPa with the introduction of 10% modifier 
to 19.2 MPa. A further increase in the content of gossypol resin leads to a decrease in 

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the studied indicator. It is known that the flexural strength depends mainly on the 
adhesion strength of the particle particles, therefore, we can talk about the positive 
effect of modification on the property of the resin, which leads to a more active 
interaction of the functional groups of the binder and filler.
The same picture is observed when testing 
specimens by breaking a perpendicular plate. Boards based on a modified binder, the 
breaking strength of the plate is significantly higher than that of unmodified ones, and 
the best result of 0.50 MPa also corresponds to a 10% content of gossypol resin in the 
composition. A further increase in the amount of modifier leads to a decrease in tensile 
strength. This is probably due to an increase in low molecular weight substances in the 
composition, which negatively affects the adhesiveness of the chips.
The increase in tensile strength in specimens based on a modified binder is 
explained by an increase in the curing of the binder, its interaction with filler particles, 
and the strength of bond adhesion at the adhesive-substrate interface. The introduction 
of gossypol resin, which contains 10-12% of nitrogen-containing substances, also leads 
to an increase in adhesive ability, and carboxyl groups deepen the degree of curing of 
the resin. 
The increase in tensile strength in 
specimens based on a modified binder is explained by an increase in the curing of the 
binder, its interaction with filler particles, and the strength of bond adhesion at the 
adhesive-substrate interface. The introduction of gossypol resin, which contains 10-
12% of nitrogen-containing substances, also leads to an increase in adhesive ability, 
and carboxyl groups deepen the degree of curing of the resin. The study of the effect 
of the modifier on the water absorption of particle boards showed that the boards 
obtained without the modifier had a water absorption of 135%, and when gossypol 
resin was added to the binder, it significantly decreased, and the lowest water 
absorption value is observed with a modifier content of 10-15%. 

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