Phenolic resin and composite molding process Progress

    Phenolic resin was the first industrialized synthetic resin, has been 100 years of history. Because of its easy to get raw materials, synthetic convenience and performance of the cured resin to meet the many requirements, so the mold plastics, insulation materials, paint, wood adhesives, etc. are widely used. In recent years, as people increased security requirements, with a flame retardant, low smoke, low toxicity and other characteristics of phenolic resin attracted renewed attention, particularly in airports, railway stations, schools, hospitals and other public buildings, facilities and aircraft interior decoration materials, the application of more and more [1].

    Compared with unsaturated polyester resin, phenolic resin, the low reactivity of the curing reaction to release the condensation of water, making the cure must be carried out under high temperature and pressure conditions, a long time before the general can only enhance the materials impregnated prepreg (fabric), then winding process for the molding process or seriously limit their application in the field of composite materials. To overcome the inherent shortcomings of phenolic resin to further improve the performance of phenolic resin to meet the needs of high-tech development, people phenolic resin a lot of research to improve the toughness of phenolic tree wax to improve the mechanical properties and heat resistance, improved process performance become a focus of the study. China in recent years have developed a series of new phenolic resin, such as the modified phenolic resin, alkenyl alkynyl modified phenolic resin, cyanate ester ring-opening polymerization of phenolic resin and phenolic resin. Can be used for SMC / BMC, RTM, pultrusion, injection, hand lay composite molding process. With the author's research work, introduced the progress of modification of phenolic resin and the RTM, pultrusion and other phenolic composite molding process of application.

1 Modification of phenolic resin

1.1 The modified phenolic resin, polyvinyl acetal

    Industrial application is the most frequently modified polyvinyl acetal resin, which can increase the resin bond strength of glass fibers to improve the brittleness of phenolic resin to increase the mechanical strength of composite materials to reduce the cure rate to help reduce molding pressure. Modified phenolic resin used is usually ammonia or magnesium oxide as a catalyst with a phenol formaldehyde resin synthesis. As modified polyvinyl butyral acetal and is generally a reduction of acetaldehyde. Generally use their soluble in alcohol, as a resin solvent. Hydroxymethyl by reaction of acetal and phenolic resin is 1 kind of synthesis of excellent special ink carrier resin.

Modified phenolic resin, polyamide 1.2

    The modified phenolic resin, polyamide, phenolic resin improves the toughness and adhesion. Modified polyamide is used as a class of hydroxymethyl amide, hydroxymethyl or active use of hydrogen in synthetic resin or the resin curing process occurred during the formation of chemical bond to achieve the purpose of modification. Fishing rod made of the resin such as thin-walled tube has excellent mechanical properties.

1.3 epoxy modified phenolic resin

    With a thermosetting phenolic resin and bisphenol A type epoxy resin mixture can be made of composite material advantages of both two kinds of resins to improve their own shortcomings, so as to achieve the purpose of modification. This mixture has excellent adhesion of epoxy resin to improve the brittleness of phenolic resin, phenolic resin also has excellent heat resistance, improved the disadvantage of poor heat resistance of epoxy resin. The modified phenolic resin by hydroxymethyl and hydroxyl groups with epoxy resin epoxy for chemical reactions, and the phenolic resin in the phenolic hydroxyl and epoxy resin in a chemical reaction, the final delivery together into a complex body structure to achieve the goal, is one kind of the most widely used method for toughening phenolic.

1.4 phenolic resin modified with silicone

    Silicone resin with excellent heat resistance and resistant to moisture resistance. Through the use of organic silicon monomer and linear phenolic resin phenolic hydroxyl or hydroxymethyl react to improve the heat resistance of phenolic resin and water resistance.

Added2011-01-05 11:41:29       Clicks2673      Source