Dielectric water content relationship

Recently, Tsai and Whang studied the dielectric constants and densities of pure polyimide and its hybrid composites and found that a proportional relationship exists between these values. The dielectric constant decreased linearly upon increasing the content of phenyltriaUcoxysilane (PhSSQ) because larger PhSSQ particles may increase the free volume and decrease the density. This work is supported by the findings of a study on other PI-PSSQ hybrid systems. The dielectric constants of the cured PI-PSSQ-like hybrid films are affected by the free volume in the materials and, probably, by the hydrophobicity of the PhSSQ-like domains because the phenyl moiety of PhSSQ is hydrophobic. Water absorption of the hybrid composite decreased-upon increasing the amount of PhSSQ, which is... 

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