Synthesis and characterization of semi-aromatic polyamides containing heterocyclic 1,3,5 s-triazine and methylene spacer group for thermally stable and colloidal property

Abstract

A new aromatic diacid (II) was synthesized and Characterized by Spectroscopic techniques namely, FT-IR, 1 H and 13 C NMR, etc. A series of aromatic aliphatic polyamides containing phenoxy s-triazine ring with methylene spacer group was synthesized from diacid (II) and various aromatic diamines by using Yamazaki Phosphorylation method. These polyamides were obtained in good yields and characterized by solubility in common organic solvent, inherent viscosity, FT-IR, X-ray diffraction analysis. All of these polyamides were found to be amorphous in morphology as indicated by XRD to posses outstanding solubilities, and to be easily dissolved in amide-type polar aprotic polar solvents. Polyamides with moderate inherent viscosity in the range 0.21 to 0.41 dL/g in N,N,dimethyl formamide solvent (DMF) at 30 ± 0.1° C. The Thermal properties of the polyamides were evaluated by Thermogravimetric analysis and Differential scanning calorimetery. These polymer shows good thermal stability with glass transition temperature (T g) of 143-223°C and their (T max) weight loss temperature were around 426-455°C, confirming their good thermal stability. The char yields of these polymers were given their limiting oxygen index LOI 32.3 to 37.5 5% values of polyamides; indicate these polymers also show good flame resistance. The NPs were negatively charged with a zeta potential of −24.2 to −37.9 mV indicating a good colloidal stability against aggregation.

The preparation of novel poly(ether-amide)s based on spiro[fluorene-9,9′-xanthene] and a polyamide/polymer-coated ZnO nanocomposite: thermal, optical, biological, and methylene blue dye adsorption attributes

“…These units disturbed the good packing of PA chains and reduced the packing density, thereby facilitating the penetration of solvent molecules through the polymer chains. Compared to previously reported work 6,7,12 due to the structure of spiro and xanthene, these polymers exhibited better solubility in less polar solvents. Meanwhile, the solubility of these PAs can depend on the chemical structure of the diacids used.…”

“…The lowest T 10% and CY value for PA-3 and PA-4 in this series of PAs can be explained by the flexible -CH 2 linkages in their diacid portion. In general, these compounds show more thermal stability than other polymers synthesized in recent years [5][6][7]10,11 which might be mainly attributed to their higher structural hardness due to presence of bulky loop units twisted into their main structure. In addition, Fig.…”

“…[1][2][3] Generally, the stiffness of the structure and intense interchain interactions of PAs endow them with high glass transition and melting temperatures which, in turn, leads to their limited solubility in most organic solvents and reduces their processability. 4 Many techniques have been investigated to overcome these shortcomings, including the incorporation of asymmetrical units, 5 polar constituents, 6 flexible bonds such as -SO 2 -, -O-, and -CH 2 -, 7,8 bulky pendant groups, 9,10 and trifluoromethyl (-CF 3 ) groups 11 within the parent chain.…”

New polyamides based on diacid with decanediamide and methylene groups and aromatic diamines

“…[4][5][6][7][8] Copolyamides from 2, 6-naphthalene diacid with a mixture of two aromatic diamines containing ether linkage and meta-catenation moiety produced aramids which were soluble in solvents namely NMP and DMSO. Solubility of aromatic polyamides was enhanced by introducing cardo [9][10][11][12][13] and bulky pendant units [14][15][16][17][18][19] such as dibenzobarrelene/ crown ethers and acyclic ethylene oxide in the polyamide backbone. Pendant bulky groups promote chain separation and improve processability.…”

Unprecedented ROP of quinazolinones to polyacylamidines using a cesium catalyst

“…6 Due to their rigid nature and strong intermolecular forces of attraction, most of these polymers decompose before they melt, posing significant challenges to their synthesis, characterization, and processing. To address these problems, a variety of flexible spacer units, such as methylene (CH 2 ) n , 7,8 cyclohexane, 9 heterocyclic triazine, 10,11 ether, 12,13 selenide, 14 sulfone, 15 thiazole, 16 isophorone, 17 aromatic hydrocarbon triptycene, 18,19 azo sulfone, 20 thioether, 21,22 imide, 23 thiourea 24 ester, 25,26 and non-coplanar 27 moieties, have been introduced. These modifications help in weakening interchain interactions by reducing the quantity of intermolecular hydrogen bonds between the amide moieties, thus improving the solubility of the ensuing polymer.…”