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Тhe effect of a hardener on the characteristics of a polyester-based coating
1  rus
Academic Editor: Blaž Likozar


Coatings based on polyester resins are a sought-after material and, when cured, have high hardness, wear resistance, and no toxic emissions during operation.

The variety of compositions and structures of saturated polyester resins contributes to the use of a wide range of materials in their production. Monomers for polyesters can be obtained from renewable raw materials, which are promising as sustainable materials.

As a result of combining polyester resins with blocked polyisocyanate resins, epoxy resins, and siloxane resins, materials with excellent properties can be obtained.

Polyester with sebacic acid, ethylene glycol, and glycerin was obtained under acid catalysis by polycondensation. After isolation, the ester was a paraffin-like mass of light gray color. The main characteristics of the polyester were studied: the acid number (mg KOH per 1 g of polyester) was 10, the mass fraction of hydroxyl groups (%) was 7.1, and the mass fraction of water (%) was 0.1. The structure of the polyester was confirmed by IR spectroscopy: there was a wide absorption band with a characteristic peak for the OH group in the region of 3450 cm-1.

Then, in order to develop cold-cured polymer coatings with high adhesion and increased weather resistance and water resistance, compositions based on the resulting polyester and epoxy resin were compiled. Several amine compounds were tested as hardeners: polyethylene polyamine; a polyamide hardener—the product of the interaction of the polymerized fatty acids of vegetable oils and polyethylene polyamines; and aliphatic amine—the product of the interaction of phenol and ethylenediamine in formaldehyde. As a result of the experiments, a coating formulation was determined that has high physical and mechanical characteristics and increased water resistance and adhesion. The tested amines exhibit different curing rates of the compounds, which are determined by the purpose of the composition.

Keywords: Polyester; hardener; coating; polycondensation; polyamine; adhesion