DCPD-Modified UPR (Low Cost)

DCPD-Modified Unsaturated Polyester Resin incorporates dicyclopentadiene (DCPD) as a reactive modifier that partially replaces the maleic anhydride unsaturation sites in the polymer backbone. This modification reduces resin cost while simultaneously lowering styrene content requirements (typically 28-33%) and improving surface quality through reduced styrene evaporation during lamination.

The DCPD modification imparts excellent surface cure properties, reducing the tacky surface phenomenon common in standard UPR laminates, and improves dimensional stability. Cured DCPD-UPR laminates exhibit reduced moisture absorption versus standard orthophthalic resins and provide a stiffer, more rigid cured product with flexural modulus of 4.0-4.5 GPa.

Viscosity at 25°C is 200-350 mPa·s, making it suitable for hand lay-up, spray-up, and pultrusion processes. The lower styrene content makes it particularly attractive in regions with strict VOC emission regulations. It is widely used in construction panels, agricultural applications, bathroom fixtures, and automotive body panels where cost efficiency is paramount and the lower reactivity (versus maleic-rich grades) is acceptable.