How to make a polymer using resorcinol and formaldehyde
Did you know that practically all of the substances around us are polymers? Thanks to their valuable properties, polymers are used in machine building, the textile industry, agriculture, medicine, automobile and ship building, aircraft construction and everyday life (textile and leather items, crockery, glue and varnishes, jewelry and other items). On the basis of high molecular compounds, rubbers, fibers, plastics, films, paints and coatings are made. Polymers are obtained by the reaction of polymerization – the reaction of the formation of a high molecular compound (a polymer) through the gradual attachment of molecules of a low molecular substance (a monomer).
In our next experiment, we will show how the reaction of the polymerization of resorcinol and formaldehyde in an acidic medium takes place.
Reagents and equipment:
- resorcinol (10 g);
- formaldehyde (10 ml);
- concentrated hydrochloric acid (10 ml);
- distilled water, test tube.
Pour 25 ml of an aqueous solution of resorcinol and 10 ml of formaldehyde into a test tube. Then add a few drops of concentrated hydrochloric acid, and observe the precipitation of the pale pink flakes of the polymer. In a few minutes, the hydrochloric acid becomes evenly distributed around the test tube, and the entire solution polymerizes to the formation of a red-pink solid polymer.
When concentrated hydrochloric acid is added to a solution of resorcinol and formaldehyde, a polymerization reaction starts, in which the molecules of resorcinol and formaldehyde begin to bond and form the long chain of a polymer.
This polymerization reaction was previously used in dentistry as a method for treating root canals, but after a number of potential complications were discovered, safer treatment methods were found.
In working with concentrated hydrochloric acid, wear rubber gloves and protective glasses, as it causes burns if it comes into contact with the eyes and skin. Conduct the experiment in a fume hood or in a well-ventilated room. Dangerous substances are used in the experiment, such as formaldehyde and resorcinol, which are toxic carcinogens.
Warning! Substances of this experiment are toxic and highly dangerous for your health. Do not try this at home. Only under professional supervision.