Triethyl Phosphate in Fiberglass-Reinforced Plastic

Fiberglass-Reinforced Plastic

Fiberglass-reinforced plastic (FRP) is a fire-resistant, composite material that combines the strength of glass fibers with the lightweight and corrosion-resistant properties of thermoplastic resins. This combination makes FRP ideally suited for various applications, including automotive parts, construction products, and marine materials. The unique properties of FRP allow for the creation of components that are not only durable but also resistant to chemical and environmental degradation. In the automotive industry, FRP is used to manufacture body panels and chassis components, offering both weight reduction and enhanced safety performance. In construction, FRP finds its application in roofing, cladding, and structural reinforcements, where its resistance to weathering and high strength-to-weight ratio are particularly beneficial. Marine applications benefit from FRP's excellent resistance to moisture and saltwater, making it an ideal material for boat hulls, decks, and other marine structures. One of the important solvents used in the production of FRP is triethyl phosphate.
 

Benefits of Triethyl Phosphate

One of the significant solvents used in the formulation of Fiberglass-Reinforced Plastic (FRP) is triethyl phosphate (TEP), a colorless, odorless liquid that helps improve the physical properties and processing of unsaturated polyester resin used in the production of FRP. TEP is an ideal solvent in this application due to its effect on resin viscosity, flame retardant characteristics, and compatibility with resin systems.

Reduces Solution Viscosity

TEP is being used in unsaturated polyester resins to reduce the solution viscosity, permitting better wet-out of fiberglass laminates. Liquid resins are formulated with fillers, pigments, and other additives that help improve the appearance or physical properties of the final product. However, additives typically increase resin viscosity, making the processing of the resin difficult. Resins often need to be sprayed or molded into useful products, and these operations require a lower viscosity liquid. Just a small amount of triethyl phosphate can significantly reduce resin viscosity in many polymer systems, enabling improved processing or higher additive-loading capabilities. In one study by Eastman, adding just 3% TEP to the polyester solution was sufficient to lower the viscosity from 1,150 to 720 mPas.

Improves Flame Resistance

TEP has been shown to provide effective flame-retardant properties when added to resin formulations. In Eastman's study, adding 6pph TEP lowered the heat deflection temperature (HDT) of the resin from 74°C to 50°C. TEP is commonly added in halogenated unsaturated polyesters due to its synergistic effects with halogenated gases, which slow down combustion when FRPs decompose at higher temperatures. As safety regulations in various industries become increasingly stringent, the demand for fire-resistant materials like FRP has grown. Due to it's flame retardant capabilities, TEP has an advantage in these composite materials.

Resin Compatibility

TEP liquid is compatible with unsaturated polyester resins, staying in suspension to maintain a clear resin. For this reason, TEP is often preferred in plastics, such as FRP, that require clarity. Antimony trioxide is also used to increase flame resistance in halogenated plastics, but it tends to settle out of polyester solutions during storage, producing an opaque resin.
 

Eastman TEP Solvent

The incorporation of triethyl phosphate in fiberglass-reinforced plastic formulations plays an important role in enhancing the performance, safety, and workability of these composite materials. Its viscosity reduction properties improve processing efficiency while its flame retardancy contributes to the safety of FRP products in various applications. Eastman's TEP Liquid product is a high-purity grade of triethyl phosphate, ensuring consistency and performance in your formulation. If you would like to learn more about TEP, and how it can significantly contribute to the innovation of your FRP products, contact us today to speak with a technical specialist and request a sample.