Photostabilization Of PVC Research Articles

Tinuvin-P metal complexes as new photo-stabilizers for PVC: Synthesis, characterization and DFT studies

Tinuvin-P metal complexes as new photo-stabilizers for PVC: Synthesis, characterization and DFT studies

Morphology and Performance of PolyVinyl Chloride Thin Films Doped with Polyorganosilanes against Photodegradation

The importance of polymeric additives has taken an important role in industrial technology and its development and the increase in the consumption period of industrial products, especially plastic products. Therefore, a different type of polymeric additive was used, which can be classified as another type of polymeric additive, where three types of polymers were synthesized as polymeric additives. These polymers differ from each other only in stereo geometry. Three geometric shapes of the polymer were synthesized, namely, ortho, meta, and para polymers. They were studied as photo stabilizers for PVC and compared as the best photostabilizer for PVC. Polyorganosiloxane was invented by various technologies. Polyorganosilanes and poly(vinyl chloride) (PVC) were combined to create homogeneous films. Various methods were used to investigate the effects of long-term irradiation on polyorganosilane-containing films. The development of side products containing polyene and carbonyl groups was observed in the infrared spectra of PVC films before, during, and after irradiation. The absorption bands' intensities of the functional groups associated with the polyorganosilanes were lower when it was present. Furthermore, it was observed that the weight of PVC films dropped less when irradiating them after hybridization with polyorganosilanes. In the presence of polyorganosilanes, there was also a minor alteration in the surface of irradiated PVC. Photodegradation of PVC is inhibited by polyorganosilanes. Hence, the role of polyorganosilanes to stabilize PVC against UV exposure has been studied.

Sulfamethoxazole as a ligand to synthesize di- and tri-alkyltin(IV) complexes and using as excellent photo-stabilizers for PVC

Sulfamethoxazole as a ligand to synthesize di- and tri-alkyltin(IV) complexes and using as excellent photo-stabilizers for PVC

UV-Absorbing Gallic Acid Derivatives as Functional Reinforcing Fillers in Poly(Vinyl Chloride) Films

The poly(vinyl chloride) PVC was photostabilized by gallic acid derivatives (0.5% by weight). The photodecomposition rate constant was reduced significantly in the existence of gallic acid derivatives along with PVC (blank). R1 compound was found to be the most effective stabilizer in photostabilization of PVC. The photodecomposition rate constant for PVC films containing R1 was found to be 1×〖10〗^(-4) compared to 8×〖10〗^(-4) sec-1 for PVC films in the absence of any additives. Different mechanisms of photostability for PVC films that involve gallic acid derivatives have been proposed.

Synthesis and characterization of gallic acid derivatives and their utilized as organic photo-stabilizers for poly (vinyl chloride)

The photo-stabilization of poly (vinyl chloride) containing 1,3,4-thiadiazole derivatives derived from Gallic acid as additives were studied. The four different substituents of 1,3,4-thiadiazole-gallic derivatives, 2-(4-substituted-phenyl)-5-(3,4,5-trimethoxyphenyl)-1,3,4-thiadiazole, (R1-R4) were prepared starting from Gallic acid and characterized by FTIR, 1HNMR and elemental analysis. The 5% concentration by weight of these derivatives (R1-R4) in PVC polymer was used to study the photo-stabilization of PVC. The photo-stabilization of PVC films were studied at room temperature under irradiation of U.V light with λ = 385 nm and an intensity of 7.75 × 10−7 Einstein dm−3 s−1. The photo-stabilization activity of these compounds was determined by monitoring the carbonyl (ICO), polyene (Ipo) and hydroxyl (IOH) indices and weight loss method with irradiation time. It was found that the (ICO), (Ipo) and (IOH) index values increased with the irradiation time increase, this increase found to depend on the type of additives, also it was found that the PVC films in the presence of additives (R1-R4) were arranged as the following trend: PVC + R1 > PVC + R2 > PVC + R3 > PVC + R4.

Viscoelastic, Spectroscopic and Microscopic Study of the Photo Irradiation Effect on the Stability of PVC in the Presence of Sulfamethoxazole Schiff’s Bases

The photostabilization of poly(vinyl chloride) (PVC) films having five Schiff’s bases derived from sulphamethoxazole has been investigated. The casting method was used to produce PVC films containing sulphamethoxazoles (0.5% by weight), in tetrahydrofuran. The photostabilization activities of five additives were determined by monitoring the hydroxyl, polyene and carbonyl indices with irradiation time. In addition, the quantum yield of the chain scission (Φcs) and the changes in viscosity average molecular weight of PVC films containing Schiff’s basses were evaluated with irradiation time. The rate of photostabilization for PVC films in the presence of five Schiff’s base additives was found to be the highest in the case of 2-hydroxybenzylidene derivative and the lowest in the unsubstituted benzylidene derivative. Several mechanisms have been suggested to explain the photostabilization of PVC in the presence of Schiff’s bases that mainly act as UV absorbers and radical scavengers for photostabilizers.

Synthesis of New Thiophene Derivatives and Their Use as Photostabilizers for Rigid Poly(vinyl chloride)

Five new thiophenes, namely,N-[(3-bromo-2-methylthiophen-5-yl)methylene]-4-methoxyaniline (4a),N-[(3-bromo-2-methylthiophen-5-yl)methylene]-3,4-dimethoxyaniline (4b),N-[(3-bromo-2-methylthiophen-5-yl)methylene]-3,4-dimethylaniline (4c), 3-[(3-bromo-2-methylthiophen-5-yl)methyleneamino]-2-methylquinazolin-4(3H)-one (4d), and 3-[(3-bromo-2-methylthiophen-5-yl)methyleneamino]-2-isopropylquinazolin-4(3H)-one (4e), have been synthesized. All of these materials brought about a reduction in the level of photodegradation of poly(vinyl chloride) (PVC) films containing the synthesized thiophenes (0.5%; by weight). The results obtained showed that the extent of photostabilization of PVC in the presence of an additive was in the order4e > 4d > 4b > 4a > 4c. For the most favorable additive (4e), the rate of appearance of infrared absorption bands of degradation products was reduced by around two-thirds, while the quantum yield of chain scission was calculated to be reduced by a factor of more than one thousand. It is suggested that the additives may help stabilize PVC by direct absorption of UV radiation and dissipation of the energy as heat or that electrostatic attraction between the additives and PVC may assist transfer of energy from excited state PVC to the additive, from where it can be dissipated.

Poly(vinyl chloride) derivatives as stabilizers against photodegradation

The photo-stabilization of polymers derived from poly(vinyl chloride) (PVC) films was investigated. The PVC and modified PVC films were produced by the casting method from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also tracked (using THF as a solvent). The quantum yield of the chain scission (Φcs) of these complexes in PVC films was evaluated and found to range between 4.79×10−8 and 7.50×10−8. Results obtained showed that the rate of photostabilization of PVC in the presence of the additive followed the trend:P1>P2>P3>P4>P5

Triorganotin(IV) complexes photo-stabilizers for rigid PVC against photodegradation

The photostabilization of poly(vinyl chloride) (PVC) films by triorganotin(IV) complexes of the type Ph3SnL, Bu3SnL and Me3SnL of the benzamidoglycin complexes was investigated. The PVC films containing concentration of complexes 0.5% by weight were produced by casting method from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also tracked (using THF as a solvent). The quantum yield of the chain scission (Φcs) of these complexes in PVC films was evaluated and found to range between 5.91×10−8 and 7.67×10−8. Results obtained showed that the rate of photostabilization of PVC in the presence of the additive follows the trend:Ph3SnL>Bu3SnL>Me3SnLAccording to the experimental results obtained, several mechanisms were suggested depending on the structure of the additive. Among them HCl scavenging, UV absorption, peroxide decomposer and radical scavenger for photostabilizer additives mechanisms were suggested.

New stabilizers for PVC based on some diorganotin(IV) complexes with benzamidoleucine

The photostabilization of poly(vinyl chloride) (PVC) films by diorganotin(IV) complexes of the type Ph2SnL2, Bu2SnL2 and Me2SnL2 of the ligand benzamidoleucine complexes was investigated. The PVC films containing concentration of complexes 0.5% by weight were produced by the casting method from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also tracked (using THF as a solvent). The quantum yield of the chain scission (Φcs) of these complexes in PVC films was evaluated and found to range between 5.77×10−8 and 7.26×10−8. Results obtained showed that the rate of photostabilization of PVC in the presence of the additive follows the trend:Ph2SnL2>Bu2SnL2>Me2SnL2According to the experimental results obtained, several mechanisms were suggested depending on the structure of the additive. Among them HCl scavenging, UV absorption, peroxide decomposer and radical scavenger for photostabilizer additive mechanisms were suggested.

Improvement of the photostabilization of PVC films in the presence of 2N‐salicylidene‐5‐(substituted)‐1,3, 4‐thiadiazole

AbstractThe photostabilization of poly(vinyl chloride) (PVC) films by 2N‐salicylidene‐5‐(substituted)‐1,3,4‐thiadiazole compounds was investigated. The PVC films containing concentration of complexes 0.5% by weight were produced by the casting method from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene, and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also tracked (using THF as a solvent). The quantum yield of the chain scission (ϕcs) of these complexes in PVC films was evaluated and found to range between 4.72 × 10−8 and 8.99 × 10−8. Results obtained showed that the rate of photostabilization of PVC in the presence of the additive followed the trend: According to the experimental results obtained, several mechanisms were suggested depending on the structure of the additive. Among them, UV absorption, peroxide decomposer, and radical scavenger for photostabilizer mechanisms were suggested. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Improved photostability of PVC films in the presence of 2-thioacetic acid-5-phenyl-1,3,4-oxadiazole complexes

The photostabilization of poly(vinyl chloride) (PVC) films by 2-thioacetic acid-5-phenyl-1,3,4-oxadiazole with Sn(II), Ba(II), Ni(II), Zn(II), Cu(II), and Ca(II) complexes was investigated. PVC films containing different concentrations of complexes ranging from 0.1% to 0.5% by weight were produced by the same casting method from THF solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl and polyene indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also tracked (using THF as a solvent). The quantum yield of the chain scission (\Phi _{cs}) of these complexes in PVC films was evaluated and found to range between 4.94 \times 10^{-8} and 1.61 \times 10^{-7}. The results obtained showed that the rate of photostabilization of PVC in the presence of the additive follows the trend: Sn(OX)_2 > Ba(OX)_2 > Zn(OX)_2 > Ni(OX)_2 > Cu(OX)_2 > Ca(OX)_2 > OX Based on the experimental results obtained, several mechanisms were suggested depending on the structure of the additive. HCl scavenging, UV absorption, peroxide decomposer and radical scavenger for photo-stabilizer additives mechanisms were suggested.

Glucoside derivatives as novel photostabilizers for rigid PVC

Glucoside derivatives of some UV absorbers have been prepared and investigated as photostabilizers for PVC in absence and in presence of Ca-Zn stearate. The results indicate a reasonable stabilizing effect of the glucosides compared with the parent UV absorbers. The prepared glucosides were also investigated as thermal stabilizers for PVC and exhibited good thermal stability compared with that of commercial Ca-Zn stearate heat stabilizer.

Spectrophotometric study of the photostabilization of PVC by a benzylidene malonate

The photo-oxidation of PVC films, stabilised by various amounts of Cyasorb UV 1988 benzylidine malonate, was studied by UV and IR spectrophotometry. A screen effect of reasonable efficiency was observed on initial rates of carboynl growth; however, for the lowest stabiliser concentrations, a relatively quick chemical transformation of the stabiliser was observed. The dependence of its rate upon the initial stabiliser concentration shows that it is due to reactions of the stabiliser with reactive species resulting from polymer photo-oxidation. These species could be chlorine radicals able to react by addition to the stabiliser double bond.