Catalysts/Curing System Polyester resin is converted from a low-viscosity liquid to a thermoset solid when mixed with an initiator (often called a catalyst), in conjunction with suitable promoters and accelerators. Commonly used catalysts for making corrosion-resistant materials are methyl ethyl ketone peroxide (MEKP), benzoyl peroxide (BPO) and cumene hydro-peroxide (CHP). Promoters are very selective in their work with peroxide catalysts and care must be taken to use the correct combinations. Peroxide Initiators The initiator is usually the final addition required to initiate the curing reaction. Promoters and/or inhibitors may be added to prepare it hours, days or weeks before it is to be used. The initiator is added immediately before use, and the amount employed is a factor that determines the working life of the resin. The most commonly used initiator systems for the resins include: Methyl Ethyl Ketone Peroxide (MEKP): Methyl et
Thermoset Resin Thermosetting resins are petrochemical materials that cure irreversibly. Cure can be brought about by heat, chemical reaction or appropriate irradiation. It is used as an adhesive as well as in semiconductors and integrated circuits. Thermosetting resins are popular because they are uncured and in a liquid state at room temperature. This allows for convenient impregnation of reinforcing fibers such as fiberglass/carbon fiber or Kevlar. A thermosetting resin is also known as a thermoset. Thermosetting resins are rigid polymeric materials that are resistant to higher temperatures than common thermoplastics. These materials are usually composed of lines of polymers, which are highly cross-linked. The heavily cross-linked structure produced by chemical bonds in thermoset materials is directly responsible for the higher mechanical and physical strength compared to thermoplastics or elastomers. However, it offers poor elas