A Green Route for Synthesis of Different Polyureas Based on Phenylurazole: Rapid Solid-state, Microwave-assisted Technique

Abstract

Solid-state microwave synthesis was found to give a simple, rapid and economical route to prepare different kinds of materials. In this investigation, a new method for solid-state polymerization reaction of 4-phenylurazole (PHU ) and 4-(4-methoxyphenyl)urazole (MPU) with different diisocyanates was developed under microwave irradiation. The reaction of PHU and MPU with hexamethylene diisocyanate, isophorone diisocyanate, and tolulyene-2,4-diisocyanate were performed under solid-state conditions in the presence or absence of dibutyltin dilaurate as a catalyst. The resulting polyureas showed good yields and moderate inherent viscosities ranging of 0.20 to 0.34 dL g-1 in N,N-dimethylformamide at 30 °C. All of the aforementioned polymers were characterized by 1 H-NMR, FT-IR spectroscopy and thermogravimetric analysis. This method was compared with solid-state polymerization under high temperature conditions and also with the solution polymerization reaction in N,N-dimethylacetamide. Under microwave-assisted, solid-state conditions, higher yields and inherent viscosities were obtained. In addition in this method we do not need to use any solvents and the polymerization reaction can be classified as a green, cost-effective and environmentally friendly method.

Investigating thermophysical properties of novel chiral nanostructured poly(amide-ester-imide)s containing different amino acids based on biological active N, N′-(pyromellitoyl)-bis-l-amino acids and diol

“…A direct and well-organized method for the preparation of chiral macromolecules is to introduce chiral elements into the polymer backbone or the side chains. [26][27][28][29][30] With the foregoing analysis in mind, and on the basis of our previous studies on chiral potentially biodegradable polymers, [31][32][33] we designed and synthesized a novel poly(amide-ester-imide)s (PAEI)s with amino acid linkage in the main chain. Polycondensation reactions of chiral pyromellitic dianhydride based on diacid monomers containing S-valine, L-methionine, L-leucine, and L-isoleucine with diol N, N 0 -(1,3,5,7-tetraoxo-5,7-dihydropyrrolo [3,4f]isoindole-2,6(1H,3H)-diyl)bis(4-hydroxybenzamide) (diol 4) were investigated.…”

Novel, thermally stable and chiral poly(amide-imide)s derived from a new diamine containing pyridine ring and various amino acid-based diacids

“…27,28 Due to these unique properties, ILs are used in various fields including catalysis, electrochemistry and separation sciences. 29–32…”