The use of new pyridine derivatives as effective photostabilizers for poly (vinyl chloride)

Abstract

This work included synthesis of several new pyridine derivatives by cyclization of compound (3) with appropriate aromatic aldehydes (4-Chloro-3-formylcoumarin, 4-bromobenzaldehyde, 4-chlorobenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde and 4-N,N-dimethylaminobenzaldehyde) in presence of malononitrile and ammonium acetate to obtain pyridine derivatives (5a-e). The new synthesized compounds have been characterized using Melting point, TLC, FT-IR spectroscopy and 1H-NMR. Five new pyridine derivatives have used like inhibitors untill Poly(vinyl chloride) (PVC) photodegradation. The pyridine derivatives have added into PVC onto a concentration from 0.5% through weight. The PVC thinlayers (40µ m thickness) have irradiated onto room temperature through ultraviolet (UV) light into up into 300 h. The changes within PVC thinlayers after irradiation have monitored through Fourier transform infrared spectroscopy, weight lack, while atomic strength microscopy. These alterations have quite remarkable within the empty PVC thinlayers liken into the ones gained when Active substances have uitilized. The pyridine derivatives have prevent the PVC photodegradation during immediate absorption from UV light, interfere through PVC chains, while touching like radical tie up while proton transfer action into stabilize the polymeric compounds.