Alkyd varnish, as a common coating, is widely used in woodworking, decoration and surface protection. It is very important to understand its preparation principle and experimental technology for mastering its application and properties. The preparation process and characteristics of alkyd resin varnish can be better understood by understanding its experimental purpose, principle, steps and requirements of experimental results.

Experimental principle

The purpose of the experiment for preparing alkyd resin varnish is to understand its preparation principle and to master the preparation technology and drying process of varnish film. The preparation process of alkyd resin coating is based on the formation of peroxide between oxygen and methylene near the double bond under the action of heat or light, which then leads to a polymerization reaction to form a cross-linked paint film. The main component of alkyd resin is linear polymer, through the reaction of fatty acid roots containing unsaturated double bonds (such as linseed oil, tung oil, etc.) with oxygen in the air, gradually forming a solid paint film, this process is called the drying of the paint film. The drying process is mainly the formation of peroxide between oxygen and methylene near the double bond under the action of heat or light, and then the polymerization reaction is triggered to form the cross-linked structure of the paint film. Drying agents, such as cobalt naphthenate, zinc, calcium, etc., can speed up this drying process. However, too thick paint film will prevent oxygen from entering and lead to slow drying, while the addition of a variety of drying agents can improve the overall drying speed.

Experimental method and principle of preparing alkyd resin varnish

Experimental procedure

The instruments required for the experiment include beakers, stirring sticks, paint brushes, and plywood templates. The reagents required mainly include linseed oil alkyd resin (50%), cobalt naphthenate (4%), zinc naphthenate (3%), calcium naphthenate (2%) and solvent gasoline. In the experimental steps, first of all, the required proportion of linseed oil alkyd resin and various drying agents, as well as solvent gasoline into the beaker for preparation, and evenly mixed with a stirring rod. The requirements of the finished product include a clear appearance without impurities, specific viscosity, non-volatile content and drying time.

Note: In the course of the experiment, it is necessary to pay attention to the mixing of varnish, uniform coating when painting the template, and workplace safety. Questions include why multiple drying agents need to be added at the same time and why applying too thick can affect the drying of the film.

Experimental method and principle of preparing alkyd resin varnish

These experimental steps and principles provide an important reference for understanding and mastering the preparation of alkyd resin varnish. In-depth study of the preparation process of alkyd resin varnish is not only helpful to deepen the understanding of its process principle, but also helpful to explore more new development directions and application prospects in the coating industry.