Reactivity indices of adamantane-containing diamines in the synthesis of polyimides

Abstract

2) 35 6t66The reactivity of adamanmne-containing diamines in the reactions with dianhydrides of 3,4,3',4"-tetraearboxydiphenyl oxide was studied as a function of the parameters of their electronic structures. It was found that the reactivity changes in parallel with the charges on the N atoms, the energy of homolytic cleavage of the N--H bond, and the basicity of diamines.

Kinetic Laws Governing the Synthesis of Adamantane-Containing Polyamido Acids and Polyimides

“…Here, as pointed out in ref. 21, a similar (linear) change is observed between ln k 1 and pKa 1 of the initial diamines, and also the values of D e of the NH bonds of these diamines, with the exception of diamine I, for which one of the amino groups is directly bound with the nucleus of the adamantane. For this diamine, D e has the lowest value in the selected series of adamantane-containing diamines (503.8 kJ/mol s, Table 3), which seems to be due to the considerable steric hindrances created by the bulky adamantane fragment for attack on this amino group by the reactant.…”

“…A higher reactivity is characteristic of adamantylene aliphatic diamines XI, IV, and X, and here aminoethyleneadamantalene groups are noted for greater reactivity, which is consistent both with their higher basicity and with the reduced dissociation energy of the NH bond, D e (ref. 21). Here, as pointed out in ref.…”

Synthesis and characterization of polyimides from bis(3‐aminophenyl)‐4‐(1‐adamantyl)phenoxyphenyl phosphine oxide

“…With microelectronic devices becoming smaller and lighter during the past decades, a low dielectric constant has become one of the critical factors for minimizing electrical power loss and delay in signal transmission in microelectronic applications 3, 4. Therefore, a number of attempts have been made to lower the dielectric constant of polyimides, including fluorination,5–8 polyimide nanofoam,9–11 the incorporation of adamantane/diamantane groups,12–18 and organic–inorganic hybrid nanocomposites 19, 20. Among such methods, fluorination has received great attention because it can improve dielectric and optical properties, as well as solubility, while lowering moisture absorption.…”

“…Meanwhile, in an effort to overcome the drawbacks of fluorinated polyimides and improve the dielectric and thermal properties of polyimides, the incorporation of adamantyl moieties has also been investigated 12–18. Because adamantyl moieties are known to impart high T g 's, excellent thermal stability, and good dielectric properties on account of their highly symmetrical molecular structure consisting of three cyclohexane rings that form a cage molecule,29 they have been introduced into polyimides, polysulfones, polyesters, and polyamides 20–32.…”