Synthesis, characterization and properties of novel polyamides derived from 4 4ʹ bis(4-carboxy methylene) biphenyl and various diamines

Abstract

Novel aromatic aliphatic diacid monomer, 4 4ʹ bis(4-carboxy methylene) biphenyl was synthesized via friedel craft acylation with acetic anhydride followed by willgerodot reaction and used in the preparation of polyamides by direct polycondensation using the Yamazaki phosphorylation reaction with commercial aromatic diamines. These polyamides were obtained in good yield with moderate-to-high-molecular-weight build up as evidenced by inherent viscosities in the range of 0.52–0.96 dlg−1. The XRD studies showed that all the polyamides were amorphous in nature and these polymers dissolved in polar aprotic solvents such as N-methyl-2-pyrrolidone(NMP),N,N-dimethylsulfoxide(DMSO), N,N-dimethyl formamide (DMF) and N,N-dimethyl acetamide. The resulting polyamides were characterized by inherent viscocity measurements, FT-IR, 1H NMR and 13C NMR spectroscopy, solubility, thermogravimetry, X-ray diffraction studies. These polyamides had glass transition temperatures between 210°C and 261°C, and their temperatures at a 10% weight loss were 620 to 710°C and 497 to 597°C in nitrogen and air atmospheres, respectively, which indicates thermally stable polymers.

Hyperbranched polymeric membranes for industrial water purification

“…DSC thermograms of all PA-NFMs show endothermic peaks in the range of 200–440 °C while PAN is exothermic in the range of 100–410 °C. The electro-spun PA-NFs exhibited a glass transition temperature in the range of 210–261 °C [ 75 ]. As observed in Fig.…”

“…5 (b), the electro-spun PA/Ch-NFs exhibited a systematic reduction in the glass transition temperature (Tg) from 220.77 °C of pure PA-NF to 217.191 °C and 216.59 °C of PA/0.75%Ch and PA/1.25%Ch respectively. This may be due to changes in the crystalline phase with increasing Ch contents thereby reducing the transition temperature of the polymer [ 75 ]. Furthermore, melting temperature (T m ) increased from 402.978 °C for PA-NFs to 433.271 and 435.541 °C for PA/Ch-NFs which indicates the enforcement of the NFs by the addition of chitosan resulting in improving the thermal stability of the PA/Ch-NFMs.…”

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.…”