Greater versatility and better performance are the hallmarks of Dow’s expanded FORTEGRA™ toughening technology line.

With the addition of two new technologies, Dow Epoxy now offers the most comprehensive portfolio of toughened epoxy resins. The line of FORTEGRA™ tougheners today includes block copolymer, carboxyl terminated butadiene-acrylonitrile (CTBN) and core shell rubber (CSR) technologies for use in composites, as well as structural adhesives, electrical laminates, castings and coatings. All FORTEGRA™ products help formulators overcome the inherent brittleness of epoxy resins without sacrificing essential epoxy thermo-mechanical properties.

The need for toughening in epoxy systems has never been greater as manufacturers extend the frontiers of composite performance in a myriad of applications such as wind turbine blades, structural aviation components, oil and gas pipelines, as well as high-performance jet skis, golf clubs and other equipment for the sports and recreation industry. FORTEGRA™ tougheners are combined with liquid epoxy resins in system formulations that increase composite ductility, fracture toughness, fatigue resistance and durability. With the use of FORTEGRA™ toughening technology, composite parts are more reliable and durable, with improved resistance to sudden impact and increased ability to bear varying loads. FORTEGRA™ enables epoxy-based composites to last longer and withstand greater wear and tear.

Julie Mongeluzi, North American Marketing Manager of Dow Epoxy, says the breadth of the FORTEGRA™ product line enables Dow to help customers identify a toughening solution that balances ductility requirements with the need to preserve essential epoxy properties.  She says the ability to choose from among several toughening technologies increases flexibility in the product design and development process.   FORTEGRA™ products now include:

  • FORTEGRA™ 100-Series Tougheners, which are based on proprietary Dow block copolymer technology.  They offer increased ductility while maintaining desirable low viscosity properties in epoxy formulations.
  • FORTEGRA™ 200-Series Tougheners, are elastomer-modified functional adducts formed from the reaction of liquid epoxy resin and a CTBN elastomer.  They are an excellent candidate to replace CTBN or other CTBN modified products to improve fracture toughness and peel strength.
  • FORTEGRA™ 300-Series Tougheners, which are stable dispersions of pre-formed novel core shell rubber (CSR) particles in epoxy resins.  They can significantly improve fracture toughness, lap shear resistance and durability, with minimal impact on thermo-mechanical properties.

Mongeluzi says FORTEGRA™ 100-Series epoxy tougheners were introduced in 2007, but with the addition of FORTEGRA™ 200 and 300, Dow now offers the most comprehensive portfolio of toughening technologies on the market.   “This gives our customers the flexibility to choose from three distinct chemistries.  By choosing the right technology, it is possible to obtain fracture resistance and impact strength without the performance tradeoffs inherent with plasticizers and other technologies designed for flexibilization.” Mongeluzi says formulation viscosity and cured properties such as glass transition temperature, corrosion resistance and chemical resistance are among the properties that can be compromised if customers lock into a particular toughening solution and try to apply it for every application need. 

Rui Xie, Dow Global Technology Leader for Specialty Epoxy Resins, notes that Dow frequently encounters confusion in the marketplace regarding the use of flexibilizers instead of tougheners to enhance the toughness of epoxy systems.  “There is an important difference in their effect on epoxy properties,” he states.  “Flexibilizers are used to change epoxy thermosets at the molecular level.  They can increase ductility but can have a negative impact on cured epoxy properties such as glass transition temperature, modulus, chemical resistance and environmental durability.”

“True toughening, on the other hand, is achieved by producing a discrete ‘phase’ separated from the epoxy matrix.  This secondary phase is often comprised of rubbery materials that relieve stresses and increase ductility.  Because the epoxy matrix is not altered due to phase separation, cured properties are less likely to be affected.  This gives FORTEGRA™ tougheners a distinct advantage over plasticizers and other flexibilizers in applications where preserving thermo-mechanical properties is essential."

With a range of toughening solutions to offer, members of the Dow Epoxy technical team are in a position to fairly assess challenges faced by customers and provide unbiased formulating recommendations, Xie says.  He also added that FORTEGRA™ epoxy tougheners are all compatible with a wide range of liquid epoxy resins and can be directly mixed or diluted with a variety of epoxy resins and diluents, enhancing their versatility and utility in a broad range of epoxy systems.  He says results achieved with FORTEGRA™ epoxy tougheners are highly consistent, reducing levels of off-spec parts and resulting scraps.

Mongeluzi says Dow understands that advances in toughening technology and expertise in choosing the right technology to meet specific performance goals are becoming increasingly important as design engineers continue to push the limits of epoxy composite applications. She says Dow plans to keep pace by continuing to develop the advanced toughener technology required to meet the performance and productivity needs of both system formulators and producers of finished composites.

Request samples of FORTEGRA™ epoxy tougheners and additional product technical information, or contact the Dow location in your region, listed below:

Europe
Toll Free Phone: +800 3 694 63 67*
Phone: +31 11567 2626
Fax: +31 11567 2828

North America
Toll Free Phone: 1-800-447-4369
Fax: 989-832-1465

Asia-Pacific
Toll Free Phone: +800 7776 7776*
Phone: +60 3 7958 3392
Fax: +60 3 7958 5598

Latin America
+55 11 5188 9222
Fax: +55 11 5188 9749

*Toll free service not available in all countries