Porous films were prepared on the base of the cardo polyimide soluble in organic solvents and modified with fluorocontaining organosilicon copolymers. The fluorinated organosilicon copolymers with various molecular weights were used as hydrophobic modifiers. It was shown that addition of modifiers leads to formation of porous structure with monomodal size distribution. Modification of the polyimide with copolymers in combination with the surface structuring resulted in formation of the highly hydrophobic porous films with contact angle 137°.
A number of thioether-containing zirconium siloxanes, differing in their composition and metal atom shielding degree with a siloxy substituent, were synthesized and characterized. Synthesis of such compounds made it possible to evaluate the effect of sulfur atoms’ presence in the cured compositions on their dielectric properties, as well as to evaluate their curing ability and influence on mechanical characteristics compared to the sulfur-free analogs obtained earlier. Studying a wide range of compositions differing in their content and ratio of metallosiloxane and silica components revealed that such systems are still typical dielectrics. At the same time, the introduction of thioether groups can provide increased dielectric constant and conductivity in comparison with previously obtained sulfur-free similar compositions in the <102 Hz frequency range (dielectric constant up to ~10–30 at frequency range 1–10 Hz). As before, the dielectric parameters increase is directly determined by the silica component proportion in the cured material. It is also shown that varying sulfur-containing zirconium siloxanes structure and functionality and its combination with previously obtained sulfur–free analogs, along with varying the functionality and rubber chain length, can be an effective tool for changing the dielectric and mechanical material parameters in a wide range (tensile strength 0.5–7 Mpa, elastic deformation 2–300%), which determine the prospects for the use of such cured systems as dielectric elastomers for various purposes.
For the first time, diacid derivative of limonene was obtained by thiol-ene reaction with mercaptoacetic acid and it was further used as a monomer for the synthesis of polyamides. Commercially available hexamethylenediamine and its siloxane analogue, bis(aminopropyl) tetramethyl disiloxane, were used as diamines monomers. It was shown that the introduction of a siloxane unit into the structure of a polyamide chain increases the molecular weight and thermal stability of the polymer (more than 300°C), and also affects its phase behavior at room temperature.
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