Аңдатпа
The electrical, physical, mechanical and thermal properties of fluorine-containing alicyclic polyimides have been investigated.It was shown that the minimum value of the dielectric constant 1.91 at room temperature and 1 kHz frequency was achieved for polymers containing only one fluorine atom in the structure.The dielectric loss tangent of new polymers was (1-4)×10 -3 .Electro-physical parameters were stable during polymer heating up to 300 °C, and at the frequency from 1 to 20 kHz.Resistivity by heating in the air up to 320-380 °C has been investigated depending on the polyimides structure.The coefficient of moisture absorption for the fluorine-containing polyimide based on dianhydride with 4,4'-oxydianiline was determined at 50% humidity and 25 °C.It was around 0.6, but after immersion in the water for 24 and 48 h was 0.8% and 1.2%, respectively.Manufactured films had tensile strength to 160-170 MPa, and elongation up to 55%.