Phenolic resin, CAS number: 9003-35-4, molecular weight: 134.133, is an organic chemical raw material. Originally a colorless or yellowish-brown transparent substance, it is often marketed with colorants to achieve colors such as red, yellow, black, green, brown, or blue. Solid phenolic resin is a yellow, transparent, amorphous block with a reddish hue due to the presence of free phenol. Its average specific gravity is approximately 1.7. It is readily soluble in alcohol but insoluble in water. It is stable to water, weak acids, and weak bases. It is resistant to weak acids and weak bases, decomposing in strong acids and corroding in strong bases. It is insoluble in water but soluble in organic solvents such as acetone and alcohol. It is obtained by the polycondensation of phenol-formaldehyde or its derivatives (formulated by the polycondensation of phenol and formaldehyde in the presence of a catalyst, followed by neutralization and water washing). Depending on the catalyst used, it can be divided into thermosetting and thermoplastic types. The development and research of phenolic resins primarily focuses on reinforcement, flame retardancy, low smoke, and molding suitability, with a focus on functionalization and refinement. Phenolic resins are primarily used in the manufacture of various plastics, coatings, adhesives, and synthetic fibers. Due to their excellent mechanical properties, heat resistance, and acid resistance, they are also widely used in industries such as corrosion protection, flame retardant materials, diamond products, and grinding wheel manufacturing.
Water-soluble or alcohol-soluble phenolic resins are used to impregnate paper, cotton, glass, asbestos, and other similar materials to provide them with mechanical strength and electrical properties. Typical examples include electrical insulation and mechanical lamination, clutch plates, and filter paper for automotive filters.
Cross-linked phenolic resins resist degradation by all chemicals, including gasoline, petroleum, alcohols, ethylene glycol, grease, and various hydrocarbons. Due to their chemical resistance, they are suitable for use in kitchen and bathroom appliances, drinking water purification equipment (phenolic carbon fiber), Bakelite tea trays, and tea sets. They are also widely used in food and beverage packaging, such as cans and pop-top cans (National Standard GB05009.069-2003), and liquid containers.
