METHOD OF PRODUCING A CROSS-LINKED PHENOL-FORMALDEHYDE POLYMERS Russian patent published in 2018 - IPC C08G8/10 

FIELD: chemistry.

SUBSTANCE: invention relates to the chemistry and technology of condensation polymers of formaldehyde with phenols. Suggested method for the preparation of cross-linked phenol-formaldehyde polymers by curing the corresponding novolaks in the presence of 30 % of 3,5-di(hydroxymethyl)-4-methylphenol at temperature of 110–140 °C followed by hot pressing at 180 °C under a pressure of 10 MPa. Proposed method allows to reduce the consumption of the hardener and to lower the temperature of the process while improving the strength characteristics of the products (an increase in the breaking stress at bending from 37.6–59.3 to 79.0–79.5 MPa, and specific impact strength from 1.9–3.1 to 4.2 kJ/m²) and their thermal characteristics (increase in the temperature of losses of 10 and 20 % of mass from 400–420 to 440 °C and from 460–480 to 500 °C, respectively, and the amount of coke residue from 53–55 to 59–70 %).

EFFECT: obtained polymers can be used to create heat-resistant materials with high strength characteristics for various branches of the national economy.

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