Patent GB-1104411-A (GB)
Title: Polyamides containing heterocyclic linkages
IPC: C08G73/06
Filed: 1965-02-26
Abstract: A polyamide has a recurring unit -NH-Y1-NH-CO-Y-CO-wherein Y and Y1 are Ar, Ar-X-Ar, Ar -X-X-Ar, Ar1-X-X-Ar1 or Ar -X-Ar1-X-Ar, Ar and Ar1 are multivalent aromatic radicals having a single, multiple or fused ring structure and X is a heterocyclic unit comprising at least one 5 or 6 membered ring containing 1-3 atoms selected from N, O, S, P, As and Se, at least one of Y and Y1 containing a heterocyclic unit and at least one point or plane of symmetry being present in each recurring unit.  Ar and Ar1 may contain 6-15 carbon atoms. Ar may be divalent and Ar1 di- or trivalent the valencies being other than ortho to each other.  X may be symmetrical or unsymmetrical, may comprise 2 fused heterocyclic rings and may be fused to Ar. Where Y and Y1 both contain heterocyclic rings these may be the same or different.  The polymer may be prepared by condensing the corresponding polyamine and polycarboxylic acid halide or from a polymer containing preformed amide links and groups which condense to give heterocyclic rings.  The polyamine monomer may be prepared by reduction of the corresponding nitrocompound.  Polymerization may be by interfacial, solid state, melt or solution methods employing heat and stoichiometric ratios of reactants.  In solution polymerization the polyamine solution which may contain up to 10% of an alkali metal or alkaline earth metal salt is cooled to 20 DEG  to 30 DEG  C. and the polyacid added as solid or solution.  The resulting polymer solution may be spun directly or the polymer isolated, by pouring the solution into water, washed, dried, redissolved and then spun.  In interfacial polymerization the polyamine or amine hydrochloride, dissolved in water together with an emulsifier and proton acceptor is reacted, with rapid stirring, with the acid in an organic solvent. The resulting polymer is filtered off, washed and dried.  In the examples polymerization is carried out in dimethyl acetamide solution containing lithium chloride.  Benzene is also used as a solvent (IV) and excess acid is neutralized with LiOH. Diamines specified include <FORM:1104411/C3/1> <FORM:1104411/C3/2> <FORM:1104411/C3/3> <FORM:1104411/C3/4> <FORM:1104411/C3/5> <FORM:1104411/C3/6> <FORM:1104411/C3/7> <FORM:1104411/C3/8> <FORM:1104411/C3/9> <FORM:1104411/C3/100> <FORM:1104411/C3/111> <FORM:1104411/C3/122> <FORM:1104411/C3/133> <FORM:1104411/C3/144> <FORM:1104411/C3/155> Acids specified include:  isophthalic terephthalic, naphthalene - 2,6 - dicarboxylic diphenyl - 4,41 - dicarboxylic, diphenyl sulphoxide 4,41-dicarboxylic and the acid chloride, <FORM:1104411/C3/166> In Example (XXX) a polymer of repeating unit <FORM:1104411/C3/177> was cyclized to <FORM:1104411/C3/188>ALSO:In Example I a diamine for use in polyamide formation was prepared as follows:  <FORM:1104411/C2/1> In Example VI a dicarboxylic acid chloride for use in polyamide formation was prepared as follows:  <FORM:1104411/C2/2> In Example XVII a diamine was prepared as follows:  <FORM:1104411/C2/3> In Example XIX a diamine was prepared as follows:  <FORM:1104411/C2/4> In Example XXI a diamine was prepared as follows: <FORM:1104411/C2/5> In Example XXV p-nitrobenzaldehyde and dithioxamide were reacted to give:  <FORM:1104411/C2/6> which was catalytically hydrogenated to:  <FORM:1104411/C2/7> In Example XXIII an analogous series of reactions was effected, starting with m-nitrobenzaldehyde.  In Example XXVIII a diamine was prepared as follows:  <FORM:1104411/C2/8>