Photostabilization of Poly(vinyl chloride) Films Blended with Organotin Complexes of Mefenamic Acid for Outdoor Applications

Abstract

This study develops a process for enhancing the photostabilization of PVC films blended with a low concentration of mefenamate–tin complex. One tri-substituted and three di-substituted organotin complexes containing mefenamate unit are synthesized, and their chemical structures are established. The reactions of mefenamic acid and a number of substituted tin chlorides gave the corresponding tin complexes in 70–77% yields. Tin complexes were blended with PVC and thin films. The effect of the addition of additives against long-term irradiation (290–400 nm, 300 h) is also tested. Changes in the infrared spectra, weight, and surface of the PVC blends due to irradiation are examined and analyzed. Any damage to the PVC surface and its chemical degradation level are noticeably low in the presence of additives. Minimal photodegradation levels and surface changes of the irradiated PVC films are observed when the triphenyltin complex is used. Such a complex is highly aromatic and can act as an ultraviolet irradiation absorber and a scavenger for hydrogen chloride and radicals produced due to the photooxidation and photoirradiation of PVC films.

Substituted Organotin Complexes of 4-Methoxybenzoic Acid for Reduction of Poly(vinyl Chloride) Photodegradation

“…The order of the efficiency of the PVC additives was 1 (triphenyltin) > 2 (tributyltin) > 3 (dibutyltin) > 4 (dimethyltin). The trend is in agreement with the order reported for other Sn complexes [29]. After 300 h, the films were physically damaged and turned dark brown, so no attempts were made to study the effect of irradiation beyond this period.…”

“…In addition, PVC stabilizers (e.g., fatty acids, metal salts, and organometallics) are used to minimize PVC photodegradation [15][16][17]. Progress in the application of new photostabilizers to reduce PVC photodegradation continues and, in recent years, polybenzimidazoles [18], polyphosphates [19], pigments [20], metal oxides [21][22][23], Schiff bases [24][25][26][27][28], and organotin complexes [29][30][31][32] have been used.…”

Modifications of Polymers through the Addition of Ultraviolet Absorbers to Reduce the Aging Effect of Accelerated and Natural Irradiation

“…Recently, we synthesized a range of UV stabilizers (e.g., aromatics, heterocycles, Schiff bases, organometallic complexes, and polyphosphates) and tested their efficiency for the stabilization of polymers [ 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 ]. These additives, at a low concentration of 0.5% by weight, led to a significant improvement in the photostability of polymers.…”

FTIR, Weight, and Surface Morphology of Poly(vinyl chloride) Doped with Tin Complexes Containing Aromatic and Heterocyclic Moieties

“…Banned additives include flame retardants (e.g., chlorinated biphenyls), plasticizers (e.g., phthalates), stabilizers (e.g., phosphites), and those containing metals [ 20 , 21 , 22 , 23 ]. Various additives such as polyphosphates [ 24 ], polybenzimidazoles [ 25 ], metal oxides [ 26 , 27 , 28 ], pigments [ 29 ], Schiff bases [ 30 , 31 , 32 , 33 , 34 ], and substituted tin complexes containing aromatic moieties [ 35 , 36 , 37 , 38 ] have been used to improve photostability of PVC.…”