Novel Flame‐Retardant and Thermally Stable Poly(Amide‐imide)s Based on Bicyclo[2,2,2]oct‐7‐Ene‐2,3,5,6‐Tetracarboxylic Diimide and Phosphine Oxide in the Main Chain: Synthesis and Characterization

Abstract

Six novel poly(amide-imide)s PAIs 5a-f were synthesized through the direct polycondensation reaction of six chiral N, N¢-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a-f with bis(3-amino phenyl) phenyl phosphine oxide 4 in a medium consisting of N-methyl-2-pyrrolidone (NMP), triphenyl phosphite (TPP), calcium chloride (CaCl 2 ) and pyridine. The polymerization reaction produced a series of flame-retardant and thermally stable poly(amide-imide)s 5a-f with high yield and good inherent viscosity of 0.39-0.83 dLg -1 . The resultant polymers were fully characterized by means of FTIR, 1 H NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation and solubility tests. Thermal properties and flame retardant behavior of the PAIs 5a-f were investigated using thermal gravimetric analysis (TGA and DTG) and limited oxygen index (LOI). Data obtained by thermal analysis (TGA and DTG) revealed that these polymers show good thermal stability. Furthermore, high char yields in TGA and good LOI values indicated that resultant polymers exhibited good flame retardant properties. N, N¢-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-L-amino acids 3a-f were prepared in quantitative yields by the condensation reaction of bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride 1 with L-alanine 2a, L-valine 2b, L-leucine 2c, L-isoleucine 2d, L-phenyl alanine 2e and L-2-aminobutyric acid 2f in acetic acid solution. These polymers can be potentially utilized in flame retardant thermoplastic materials.

Fabrication and study of thermal and combustion resistance of DOPO‐functionalized polyamide reinforced with organo‐modified Mg(OH)2 nanoparticles

“…Many studies have shown that polymers containing phosphorus functional groups, such as phosphonate, 10 phosphinate 11 or phosphine oxide groups, 12 can improve the flame retardancy, solubility and adhesion to metal oxides and metal hydroxides 13 . Many phosphorus‐containing monomers have been proposed for the synthesis of flame‐retardant polymers, such as polyamides with some improved essential properties such as solubility in organic solvents, thermal stability and combustion resistance 14–19 …”

Preparation of novel pyridine-based poly(ether amide)s via three different routes and investigation of their properties

“…[12][13][14] Consequently, attempts have been made to develop structurally modified macromolecules having enhanced solubility, in order to improve their process ability while maintaining good thermal stability. [15][16][17][18][19][20][21][22][23][24] This article presents preparation of a new diaminecontaining ether, amide, pyridine, and naphthyl units in its structure for preparation of related poly(ether amide)s (PEAs) with high thermal stability and improved solubility. The approach of obtaining new PEAs with improved solubility without too much sacrificing their thermal stability was mainly based on the structure of diamine containing: (a) flexible ether linkages: insertion of flexible linkages (-O-) lowers the segmental rotational barrier and increases the degree of conformational freedom leading to increased solubility; (b) amide groups: inclusion of amide groups into the polymer backbone increases the thermal stability; (c) pyridine polar units: presence of heterocyclic ring in the main chain of the synthetic polymer induces definite properties to the polymer.…”

Synthesis and characterization of novel heat resistance poly(amide‐imide)s from N,N′‐[2,5‐bis(4‐aminobenzylidene) cyclopentanone] bistrimellitimide acid and various aromatic diamines

“…Therefore, preparation of soluble polyimides without perceptible loss of favorable properties has been a major research interest, and a great deal of efforts has been made to improve the processing characteristics of this class of polymers. One of the successful approaches to improve solubility is the incorporation of other functional groups such as amide,4–11 ester,12, 13 urethane,14, 15 and urea16, 17 linkages along the polymer skeleton.…”