Processable Laminating Resins with Improved Moisture Resistance, Toughness and Moderate Temperature Capability. Part II

摘要

Incorporation of 10 mole percent 4,4'- dicyanatobiphenyl into the AF-R-10 resin system derived from resorcinol dicyanate resulted in an approximate 50% reduction in water pickup in humid environ-ments. Outstanding initial thermomechanical response of Modmor II graphite fiber laminates was developed wherein essentially theoretical flexural strengths and moduli were maintained throughout the temper-ature range of room temperature to 365 F. Laminate response after humid aging (28 days at 120 F AND 95+% relative humidity) showed complete retention of room temperature properties but a fall-off at 365 F. Very high shear strength adhesive bonds which had good resistance to water boil resulted from the same system. Alternate dicyanate resins, notably isopropylidine-4,4'-bis(2,6- dimethylcyanatobenzene), show very low moisture pickup values (0.5-1.0%) both in powdered resin and laminate form. Laminate properties and adhesive bonds suffered in comparison to AF-R-10 based systems, but promising results were obtained in both humid aging response (laminates) and water boil studies (adhesive bonds). (Author, modified-PL)