Wet-laid, non-woven chopped strand mats that are soft, flexible, and resistant to styrene are provided. The mats are at least partially coated with a binder composition that includes a thermosetting binder resin, a silane coupling agent, a hydrocarbon-based antifoaming agent. Optionally, a crosslinking agent, such as a resin-based crosslinking agent, may be included in the composition. In one or more embodiments, the chopped strand mats are formed of chopped glass fibers having diameters from about 5 to about 30 microns and lengths from about 0.5 to about 2.0 inches. The softness and flexibility of the chopped strand mats enable the formation of pultruded products having complex shapes. Additionally, the resistance to styrene monomers provided by the binder composition makes the inventive mats particularly suitable for pultrusion processes.