Phenol formaldehyde resin. Reception and application. Properties

Phenol-formaldehyde resin is a synthetic resin having the properties of thermosets or thermosets. Such resins are oligomeric or liquid substances obtained by polycondensation of formaldehyde with phenol in an acidic or alkaline medium (resole, novolac resins or bakelites). This further affects the properties of the final product.

Properties of phenol-formaldehyde resins

Phenol-formaldehyde resin (the formula [-C6H3 (OH) -CH2-] n) has a high electrical insulating property, good corrosion and mechanical stability. Perfectly soluble in aromatic and aliphatic hydrocarbons, ketones and chlorinated solvents. It also dissolves in polar solutions and aqueous solutions of alkalis. After curing, phenol-formaldehyde resins are converted into thick-cross-linked polymers of a microheterogeneous amorphous structure.

Where is phenol-formaldehyde resin used?

- in the production of plastics: hardened resins are called resins, solidified in the presence of sulfonic acids of petroleum - by carbolites, in the presence of lactic acid - by neoleucrinates;

- in the production of varnishes, synthetic glues, bearings, brake linings, billiard balls;

- from the carbolite (hardened phenol-formaldehyde resin), the cases of multimers of some Soviet models were made;

- also this substance is used in the quality of the binder component for the production of filled press compositions with different fillers (wood flour, fiberglass, cellulose), wood chipboard and fibreboard, casting and impregnating compositions (for fiber-filled and woven materials, for plywood), Adhesives.

Phenol-formaldehyde resin: preparation and ecology

Both formaldehyde and phenol, used in the production of phenol-formaldehyde resin, are poisonous and flammable substances. Phenol-formaldehyde resin adversely affects the human body: causes eczema and dermatitis. Moreover, formaldehyde has also a carcinogenic effect.  

Bakelite is the product of solidification of phenol-formaldehyde resin in the presence of a catalyst. This substance is of great importance in various spheres of human life. Bakelite conducts heat poorly, but exhibits good resistance to mechanical damage: shock, shock, friction, or pressure. Can be machined on a special lathe. Is a good insulator. Divorced alkalis, acids and water do not act on it, except for concentrated sulfuric or nitric acids. Resistant to +300 degrees, with a higher combustion temperature does not occur.

It was originally created in order to become a replacement for shellac - a special resin, produced in nature by tropical lacquer worms.

Phenoplasts. Application

Phenoplasts are plastics that are obtained by hardening formaldehyde resins at elevated temperature in combination with any filler. At present, this material is unsurpassed in its properties. With the use of phenolists produce:

- substance intended for the manufacture of printed circuit boards - getinaks;

- a substance for creating a structural material - textolite;

- inexpensive elements for board games - checkers, dominoes, chess;

- some elements of kitchen accessories: handles for gas stoves, kettles and knives, pots and pans;

- glue bakelito-phenolic;

- Electrotechnical products - sockets, plugs, electric meters, switches, relays, electric motor housings, terminal boxes, magnetic starters, etc .;

- parts for mechanical engineering, for example, steps for escalators, various tips and handles;

- costume jewelery, souvenirs, stationery, some details of watches.