Specifications include, but are not limited to: A.2.1 Fibers Fiber sizings and coupling agents shall be compatible with the resin system used to impregnate them. A.2.2 Matrix Resins Commercial grades of vinyl ester and epoxy resin systems are permitted provided the finished product meets the material property requirements before and after durability conditioning as set forth in Section A. Styrene is permitted to be added to the polymer resin during processing. Added styrene shall be less than 10 percent by mass of the polymer resin. The amount of styrene, as a mass percentage of the polymer resin, added during processing shall be reported per Section A.5.3. A.2.3 Fillers and Additives Commercial grade inorganic fillers such as kaolin clay, calcium carbonate, and alumina trihydrate shall not exceed 20 percent by mass of the polymer resin constituent.
