Preparation and characterization of novel optically active poly(vinyl alcohol-co-vinyl ester) in nonaqueous medium using l-phenylalanine as a chiral material

Abstract

In this investigation, poly(vinyl alcohol) was chemically modified by the introduction of different amounts of N-phthaloyl-L-phenylalanine. The modification was carried out by the reaction of PVA hydroxyl groups with (2S)-3-phenyl-2-phthalimidylpropanoyl chloride using N,N-dimethyl acetamide/lithium chloride as a reaction media. The novel copolymers obtained were characterized by spectroscopic techniques, elemental analysis, X-ray diffraction and thermal methods. Optical rotation and viscosities were also measured. The degree of esterification was determined by (1)H-NMR. The influence of reagent molar ratio on the degree of modification was also evaluated. The vinyl(3-phenyl-2-phthalimidopropanoate) content in the copolymer was attained up to 52%. Thermal stability of the copolymers was checked by thermogravimetric analysis and differential thermogravimetric analysis. All copolymers displayed improved thermal stability compared to the parent polymer.

Applications of ultrasound for modification of zinc oxide and fabrication of optically active poly(amide-imide)/zinc oxide bionanocomposites

“…Optically active polymers, including α-amino acids have are expected to be nontoxic, biocompatible, and biodegradable. [15,16] Optically active poly(amide-imide) (PAI) originate from the presence of chiral elements in PAI and encompass desirable properties of both polyamides and polyimides such as high thermal stability, good chemical resistance, excellent mechanical properties, and good process ability. In recent years, Mallakpour and coworkers reported on the synthesis and characterization of a new class of wholly aromatic and optically active polymers containing amino acid pendant groups by condensation polymerization.…”