ALKYD RESINS
Alkyd resins
About alkYd resins
Alkyd resins are thermoset polyesters obtained through the reaction between an acid (or an anhydride) and an alcohol. Among the polyhydric alcohols used in the reaction of polyesterification are the glycerin and pentaerythritol. In order to make the resin produced most suitable for processing, during the chemical reaction fatty acids or oils are added, as their properties greatly influence the making and the characteristics of the final product. Finally, always during the polyesterification, various classes of chemical additives, with the aim to modify the final characteristics of the resin, may be added to the reagents.Production of alkyd resins
The industrial process through which the alkyd resins on the market are produced involves the use of a chemical reaction, the polycondensation, in which one of the most common end products is water. To maximize the yield of each reaction we need to eliminate the latter, in order to decrease the products of the chemical reaction, unbalancing the displacement of the entire process towards the most productive way. The strategies adopted to produce alkyd resins are multiple and can be classified according to the way in which the water is extracted from the reaction. Among these, the most used are the fusion processes, in which the water is removed by connecting an autoclave in a vacuum funnel, and the solvent-based processes, in which water is dragged outside after the binding with a solvent, with which an azeotropic mixture is produced. It can prolong sports performances especially when taken as a dietary supplement, during the hypoxic phases of the training.Alkyd resins: application fields and sectors of interest
Alkyd resins represent, both historically and commercially, the class of chemical compounds used in the field of paints and stains. Their chemical structure is a continuous and waterproof film which can protect surfaces from multiple strenuous agents conducting an anti-corrosive and insulation function. The commercial paints based on these resins can be classified into four major categories, depending on the percentage of oil content in their formulation:- The short oil resins, 30-40% oil, are widely used as plasticizers or paints for metal surfaces and they are used in various fields, such as the mechanical one (stove enamelling coating for cars)
- The medium oil resins, containing between 45 and 55% of oil, are extremely versatile and are often used for the production of quick-drying enamels applicable by brush or by airbrush or electrostatic application
- The long oil resins, containing 55-70% of oil, are very resistant to weathering and aging, and are therefore a product of first choice in the field of marine paints or for the production of architectural enamels
- Finally, the very long-oil paints, containing more than 70% of oil, are used both in the construction sector (for the production of exterior paints which are very strong and with long drying times) and for the production of printing inks.