Studing Some Dielectric Properties and Effective Parameters of Composite Materials Containing of Novolak Resin


Dielectric constant (εr ) and dielectric strength (Ebr) of composite materials thatconsist of Novolak reinforced with glass fiber, Novolak reinforced with asbestosfiber and Novolak reinforced with (60%) ratio of glass fiber and asbestos havebeen Studied. The specimens were made in different ratios ofHexamethylenetetramine (HMTA) content of (10%) and (14%), Then a studywas made on influence of (HMTA) on dielectric constant (εr ) and dielectricstrength ( Ebr) of these speciments. It was found that permittivity (εr ) anddielectric strength (Ebr) for composite materials are dependent matrix the typesand properties of reinforcing materials.Then relation between dielectric constant (εr) and frequency and temperatureand percentage moisture absorption was studied. It was found that dielectricconstant increases when the temperature and percentage moisture absorptionincrease, whereas dielectric constant (εr) is dependent on capacity of compositematerials.