Synthesis and characterization of some novel polyamides containing diacetylene side groups

Abstract

A series of novel polyamides containing diacetylene groups as side chains were prepared by Cadiot-Chodkiewcz-coupling of polymer precursors bearing 2-propynyloxy side groups with 4-bromo-3-butyn-1-01. The conversion of the acetylenic groups was in the range of 87.5-96.5% depending on the chemical structure of the polymer backbone. The polymers are highly amorphous and undergo random cross-linking on heating. Thermally treated polymer films show third-order nonlinear optical susceptibility x (3) of the order of lo-'' esu (= lo-'* m5N2).

Dimensionally and thermally stable polymer, containing disordered graphitic structure and adamantane

“…Generally, diethynyl unit-containing polymers show two absorption bands, 2150 and 2260 cm À1 , in the region of 2100-2300 cm À1 , corresponding to symmetrical and antisymmetrical diethynyl stretching, respectively. 15 The results correlate well with those of the 1 H NMR, clearly indicating that the oxidative coupling gave rise to oligomer with only internal diethynyl units. The equivalents of 6 used were sufficient to fully end-cap all of the terminal ethynyl units.…”

“…Free acetylenes are completely absent from the spectrum of O‐1:4 , and the absorption band characteristic of the diethynyl units at 2139 and 2213 cm −1 appeared. Generally, diethynyl unit‐containing polymers show two absorption bands, 2150 and 2260 cm −1 , in the region of 2100–2300 cm −1 , corresponding to symmetrical and antisymmetrical diethynyl stretching, respectively 15. The results correlate well with those of the 1 H NMR, clearly indicating that the oxidative coupling gave rise to oligomer with only internal diethynyl units.…”

“…The diphenyldiethynyl group was chosen as a crosslinking unit 14 because (A) its low reactivity at temperature below 180 8C increases the stability of the oligomer, (B) the thermal crosslinking generates a high crosslinking density 9 and occurs at significantly lower temperature than the diphenylethynyl unit in analogous oligomer, 15 (C) the crosslinking reaction proceeds without the evolution of volatiles, resulting in the formation of void-free film, and (D) most importantly, the crosslinking reaction results in the formation of highly extended polycyclic aromatic structures that would increase Young's modulus and reduce CTE of the resulting polymer.…”

Solid State Polymerization of Diacetylenes with Amide Groups

“…Reaction between 4-cyanophenol and 3-bromo-1-propyne gave 4-(2-propynyloxy)benzonitrile [8]. The cyano group was transformed to an aminomethyl group by a reduction with lithium aluminum hydride.…”

Recent developments and applications of the Cadiot–Chodkiewicz reaction

“…In general, less acidic alkynes have a tendency to undergo homocoupling rather than cross-coupling reactions. The Cadiot-Chodkiewicz coupling reaction has very high functional group tolerance and it enables the coupling of acetylene moieties containing alcohols, 25 epoxides, 26 amines, 27 amides, 28 carboxylates, 29 carboxylic esters, 30 disulfides, 31 silyl-protected acetylenes 32 and even nitroxyl radicals. 33 a. Alcohols, amines and carboxylate esters 1-Bromoalkynes 39 were coupled with propargyl alcohol 40 under normal Cadiot-Chodkiewicz reaction conditions at 50 °C affording the expected diacetylene in yields ranging from 23% to 31%.…”