HYPOX® RF933 adduct is an epoxy phenol novolac resin modified with CTBN. HYPOX RF933 has a functionality of 2.6 and an elastomer content of 20%. The rubber improves the toughness of cured epoxy formulations through development of two phases during cure. Compared to DGEBA (EEW 188 g/eq) modified at an equal rubber level, HYPOX® RF933 adduct should provide improved chemical and heat resistance because of its higher functionality. Formulations incorporating HYPOX® RF933 adduct will exhibit improvements in impact and thermal cycling resistance, peel and tensile shear strengths and low-temperature mechanical properties compared to non-rubber-modified epoxy formulations. The table below presents the effects of the incorporation of liquid rubber on some cured properties of an EPALLOY® 8250/dicyandiamide formulation. The use of alternate curing agents can be expected to produce different test results. HYPOX® RF933 adduct should be considered for use as the sole resin or as a part of the resin component of your formulation. The optimum concentration of HYPOX® RF933 adduct should be determined empirically. Typical applications generally incorporate 5-15 phr (parts per hundred parts resin) rubber to achieve optimal toughness; higher concentrations improve flexibility.