It was shown that the optical and dielectric properties of polyimides (PIs) are affected by both the presence of an alicyclic fragment and the non-coplanarity of the structural elements of the polymer chain. The combination of these factors contributed to an increase of the transparency of the PIs in the optical range and a decrease of the dielectric constant. It was determined that the introduction of 20 mol.% adamantane-containing diamine into the PI structure contributed to its more complete amorphization and increased its transparency.

The hydrolytic stability of polyimide films (PI) in a 0.9% sodium chloride solution in the temperature range of existing biological objects was studied. The kinetic parameters of hydrolysis of PI films were calculated. It was established that the hydrolysis rate constant of an adamantane-containing film was significantly lower than that of an industrial Kapton film. The dielectric constant after hydrolysis was determined. It was shown that the dielectric properties of the adamantane-containing polymer remained unchanged under the hydrolysis conditions.

Optically transparent polyimides (PIs) containing adamantane moieties in the structure of diamine unit were synthesized, and their properties were evaluated. The quantum-chemical calculations were also performed and revealed the energy difference (As) between the HOMO of the diamine and LUMO of the anhydride moieties for a large range of adamantane-containing PIs, which is usually associated with the optical absorption of organic compounds. It was found that the value of As does not always determine the optical properties of PI, especially in the case of PI with dianhydride moieties capable of strong intermolecular interactions. The presence of methyl groups at the core of adamantane-containing diamine leads to amorphization of the polymer, causing a positive effect on the optical properties of PI.

New (co)polyimides possessing good thermal and physicomechanical characteristics, high hydrolytic stability, and transparency at the best world level were synthesized. It was shown that, depending on the natures of diamine and dianhydride used in the synthesis, the optical properties of polymers also change. These properties of (co)polyimide films correlate with the ΔE value, which is defined as the difference between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies of the polyimide repeating unit. It was shown that the use of 1,2-dichlorobenzene makes it possible to obtain high-molecular-weight (co)polyimides with a set of enhanced performance characteristics.

The regularities of the reduction of adamantane-containing unsaturated nitrile-nickel-aluminum alloy are investigated. It has been shown that under the conditions of synthesis it is possible to carry out the simultaneous reduction of both the double bond and the nitrile group. It was found that the reduction of nitriles containing 1 hydroxyl group in the position leads to a significant decrease in the rate of the process. The effect of the grain size composition of the alloy and damping additives on the reduction of unsaturated nitriles has been studied.