Photostabilization Of Poly Research Articles

Photo Stabilizing Efficiency Of Poly(methyl methacrylate) Based On Metal Ion Complexes Of Saccharine

The photostabilization of poly(methyl methacrylate) (PMMA) films having saccharine complexes of Zn(II), Cd(II), Hg(II), Fe(III), Ni(II) and Cu(II) complexes was investigated. The production of PMMA films containing such complexes (0.5% by weight) was carried out by the casting method using THF. The photostabilization activities of the compounds were determined by monitoring the carbonyl and hydroxyl index with irradiation time. Evaluation of stabilizing efficiency of PMMA by ultra-violet spectroscopy to investigate photodecomposition rate constant (kd) for PMMA films in the absence and presence of saccharine complexes. The changes in the viscosity average molecular weight of PMMA with irradiation time were evaluated. The rate of photostabilization for PMMA in the presence of the additives was found to follow the order Ni(sac) > Cu(sac) > Zn(sac) > Cd(sac) > Hg(sac) > Fe(sac). Depending on the structure of the additive, such as a peroxide decomposer, UV absorption or a radical scavenger for the photostabilizer. Keywords: Photodegradation, UV stabilizers, PMMA, Saccharine.

Photo Stabilization of Poly (Vinyl Chloride) Films by Some Nickel Complexes

Photo Stabilization of Poly (Vinyl Chloride) Films by Some Nickel Complexes

Inorganic tin(IV) complexes as photo-stabilizer for PVC

ABSTRACT. Five organotin(IV) complexes including captopril (ligand) were employed in small amount as photostabilizers for poly(vinyl chloride) (PVC) when irradiated by UV light. Polymer’s samples were cast into films in order to conduct the UV exposure impact. The photodegradation rate constant (kd) of blank and organotin(IV) complexes embedded PVC specimens were investigated in this work. The kd values of filled samples were lower than the blank one, which indicates higher stability of these embedded films. Among these additives, triphenyltin(IV) showed the highest stability effect.
 
 KEY WORDS: PVC, Organotin(IV) complexes, Photostability, Photodegradation, UV light
 
 Bull. Chem. Soc. Ethiop. 2023, 37(3), 771-777. a
 DOI: https://dx.doi.org/10.4314/bcse.v37i3.18

Improving the Photostabilization of Poly(vinyl chloride) Using 4-(benzylideneamino)benzenesulfonamide Tin Complex

The photostabilization of poly (vinyl chloride) (PVC) film filled with an organotin complex in its structure was examined and compared with the blank PVC film. The organotin (IV) complex that contains 4-(benzylideneamino) benzenesulfonamide as a ligand was synthesized and applied as a PVC photostabilizer. The impact of the complex on the polymer was assessed by comparing the properties of the films with and without the complex, before and after irradiation, using Fourier transform infrared spectroscopy, weight loss, viscosity change, atomic force microscopy, and field emission scanning electron microscopy (FE-SEM). Results showed that the complex film had lower weight loss, gel content, and molecular weight deterioration than the plain PVC film. Also, surfaces of the complexes-filled films were smoother, less lumpy, and more homogeneous. These findings were obtained via the FE-SEM and light microscope images and confirmed by measuring the roughness factor. The organotin (IV) complex proved its activity in delaying the photo-degradation of PVC by several mechanisms. Ultimately, the Tin complex has effectively protected the PVC film against irradiation.
 The photostabilization of poly (vinyl chloride) (PVC) film filled with an organotin complex in its structure was examined and compared with the blank PVC film. The organotin (IV) complex that contains 4-(benzylideneamino) benzenesulfonamide as a ligand was synthesized and applied as a PVC photostabilizer. The impact of the complex on the polymer was assessed by comparing the properties of the films with and without the complex, before and after irradiation, using Fourier transform infrared spectroscopy, weight loss, viscosity change, atomic force microscopy, and field emission scanning electron microscopy (FE-SEM). Results showed that the complex film had lower weight loss, gel content, and molecular weight deterioration than the plain PVC film. Also, surfaces of the complexes-filled films were smoother, less lumpy, and more homogeneous. These findings were obtained via the FE-SEM and light microscope images and confirmed by measuring the roughness factor. The organotin (IV) complex proved its activity in delaying the photo-degradation of PVC by several mechanisms. Ultimately, the Tin complex has effectively protected the PVC film against irradiation.

Impact on Poly(Vinyl chloride) of trimethoprim schiff bases as stabilizers

Poly(vinyl chloride) PVC materials are used in many industrial and household outdoor applications which exposed to sunlight ultraviolet. This exposure motivates photo-degradation of the PVC and hence, reduces its life time and leads to undesirable physical properties. Herein, three new Schiff bases containing a trimethoprim moiety were investigated as photo-stabilizers for poly(vinyl chloride) against photo-decomposition. Merely 0.5% by weight of these Schiff bases was mixed with the polymer to form blend films with thickness of (40 µm). The films were irradiated for a period of time from 0 to 300 h and the irradiation impact on the PVC stabilization was monitored every 50 h. The efficiency of these additives as photo-stabilizers was investigated as a function of different parameters during the course of irradiation, such as weight loss, growing carbonyl and alkene groups as well as the surface morphology of the prepared films. The changes during irradiation were obvious for the blank films in comparison to the films containing the new additives. Therefore, these Schiff bases were found to act as photo-degradation inhibitors through reducing the elimination of hydrogen chloride molecules and as free radical scavengers or peroxide decomposers.

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

Poly(vinyl chloride) suffers from degradation through oxidation and decomposition when exposed to radiation and high temperatures. Stabilizers are added to polymeric materials to inhibit their degradation and enable their use for a longer duration in harsh environments. The design of new additives to stabilize poly(vinyl chloride) is therefore desirable. The current study includes the synthesis of new tin complexes of 4-methoxybenzoic acid and investigates their potential as photostabilizers for poly(vinyl chloride). The reaction of 4-methoxybenzoic acid and substituted tin chlorides gave the corresponding substituted tin complexes in good yields. The structures of the complexes were confirmed using analytical and spectroscopic methods. Poly(vinyl chloride) was doped with a small quantity (0.5%) of the tin complexes and homogenous thin films were made. The effects of the additives on the stability of the polymeric material on irradiation with ultraviolet light were assessed using different methods. Weight loss, production of small polymeric fragments, and drops in molecular weight were lower in the presence of the additives. The surface of poly(vinyl chloride), after irradiation, showed less damage in the films containing additives. The additives, in particular those containing aromatic (phenyl groups) substitutes, inhibited the photodegradation of polymeric films significantly. Such additives act as efficient ultraviolet absorbers, peroxide quenchers, and hydrogen chloride scavengers.

Tin-Naphthalene Sulfonic Acid Complexes as Photostabilizers for Poly(vinyl chloride).

Poly(vinyl chloride) degrades when exposed to ultraviolet light for long durations; therefore, the photostability of polymeric materials should be enhanced through the application of additives. New organotin complexes containing 4-aminonaphthalene-1-sulfonic acid were synthesized and their role as poly(vinyl chloride) photostabilizers were evaluated. The reaction of 4-amino-3-hydroxynaphthalene-1-sulfonic acid and appropriate di- or trisubstituted tin chloride (triphenyltin chloride, tributyltin chloride, dibutyltin dichloride, and dimethyltin dichloride) in methanol under reflux gave the corresponding tin-naphthalene complexes with yields of 75%–95%. Elemental analyses and spectroscopic techniques including infrared and nuclear magnetic resonance (proton and tin) were used to confirm their structures. The tin complexes were added to poly(vinyl chloride) to produce thin films that irradiated with ultraviolet light. Various parameters were assessed, such as the weight loss, formation of specific functional groups, changes in the surface due to photoirradiation, and rate constant of photodegradation, to test the role played by the organotin complexes to reduce photodegradation in polymeric films. The results proved that organotin complexes acted as photostabilizers in these circumstances. The weight loss, formation of fragments containing specific functional groups, and undesirable changes in the surface of polymeric films were limited in the presence of organotin complexes. Organotin complexes containing three phenyl groups showed the most desirable stabilization effect. These act as efficient primary and secondary photostabilizers, and as decomposers for peroxides. In addition, such an additive inhibits the dehydrochlorination process, which is the main cause of poly(vinyl chloride) photodegradation.

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

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.

Tin Complexes Containing an Atenolol Moiety as Photostabilizers for Poly(Vinyl Chloride)

The lifetime of poly(vinyl chloride) (PVC) can be increased through the addition of additives to provide protection against irradiation. Therefore, several new tin complexes containing atenolol moieties were synthesized and their photostabilizing effect on PVC was investigated. Reacting atenolol with a number of tin reagents in boiling methanol provided high yields of tin complexes. PVC was then mixed with the tin complexes at a low concentration, producing polymeric thins films. The films were irradiated with ultraviolet light and the resulting damage was assessed using different analytical and surface morphology techniques. Infrared spectroscopy and weight loss determination indicated that the films incorporating tin complexes incurred less damage and less surface changes compared to the blank film. In particular, the triphenyltin complex was very effective in enhancing the photostability of PVC, and this is due to its high aromaticity (three phenyl rings) compared to other complexes. Such an additive acts as a hydrogen chloride scavenger, radical absorber, and hydroperoxide decomposer.

Photostabilization of Poly(vinyl chloride) by Organotin(IV) Compounds against Photodegradation.

Poly(vinyl chloride) (PVC), a polymer widely used in common household and industrial materials, undergoes photodegradation upon ultraviolet irradiation, leading to undesirable physicochemical properties and a reduced lifetime. In this study, four telmisartan organotin(IV) compounds were tested as photostabilizers against photodegradation. PVC films (40-µm thickness) containing these compounds (0.5 wt%) were irradiated with ultraviolet light at room temperature for up to 300 h. Changes in various polymeric parameters, including the growth of hydroxyl, carbonyl, and alkene functional groups, weight loss, reduction in molecular weight, and appearance of surface irregularities, were investigated to test the efficiency of the photostabilizers. The changes were more noticeable in the blank PVC film than in the films containing the telmisartan organotin(IV) compounds. These results reflect that these compounds effectively inhibit the photodegradation of PVC, possibly by acting as hydrogen chloride and radical scavengers, peroxide decomposers, and primary photostabilizers. The synthesized organotin(IV) complexes could be used as PVC additives to enhance photostability.

Synthesis and Identification of Heterocyclic Compounds (Oxazepine, Tetrazole) Derived from Benzidine as Photostabilizing for Poly vinyl chloride

This research describes preparation of new four compounds (A2-A5) having 1,3-oxazepine and Tetrazole rings. The first step involves reaction of benzidine (A1) with aromatic aldehyde (cinnamaldehyde) in ethanol as a solvent in the presence of acid as catalyst to yield the Schiff base (A2), Schiff base (A2) was condensed with maleic anhydride and phthalic anhydride in dry benzene to give a seven-membered heterocyclic ring derivative (A3, A4), In addition, we synthesis novel tetrazole derivative (A5) from the reaction of Schiff base (A2) with sodium azide in tetrahydrofuran. The structure of synthesized compounds were identified by spectral methods [FTIR, ¹H-NMR, and ¹³C-NMR] and measurement physical properties. The photo stabilization of poly (vinyl chloride) films by compounds (A1-A5) was studied. The Photostabilization activities of these compounds were determined by monitoring the carbonyl and hydroxyl indexes values with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were studied by using tetrahydrofuran as a solvent. The influence of concentrations additives (range 0.1-0.5wt) on the rate of photodegradation and Photostabilization course was studied. Therefore, we found that was an increase Photostabilization rates with increasing concentrations of additives. In addition, Studying the effect of film thickness and the results showed that an increase in film thickness would reduce the rate of photolysis. The results indicated that Photostabilisation proportion of plastic in the presence of additives follow the trend: (PVC blank) > PVC+A1> PVC+A2 > PVC+A5> PVC+A4> PVC+A3. According to the results obtained, it proposed mechanisms depending on the structure of the additive.

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.

Poly(Vinyl Chloride) Doped by 2-(4-Isobutylphenyl)Propanoate Metal Complexes: Enhanced Resistance to UV Irradiation

The photostabilization of poly(vinyl chloride) (PVC) films in the presence of 2-(4-isobutylphenyl)propanoate metal complexes (0.5 wt%) was investigated at room temperature under ultraviolet radiation (\(\lambda = 320 \hbox { nm}\)) for 300 h. The changes in various functional groups indices, viscosity average molecular weight and quantum yield of the chain scission of PVC films were monitored upon irradiation. The metal complexes used showed decreases in PVC films photodegradation. The quantum yield for the chain scission was measured exhibiting a range of \(2.054 \times 10^{-6}\) and \(1.005 \times 10^{-7}\). The photostabilization of poly(vinyl chloride) in the presence of metal complexes was in the order \(\hbox {ZnL}_{2} (\hbox {H}_{2}\hbox {O})_{2}< \hbox {CdL}_{2} (\hbox {H}_{2}\hbox {O})_{2}<\hbox {CuL}_{2}< \hbox {SnL}_{2} (\hbox {H}_{2}\hbox {O})_{2}<\hbox {NiL}_{2} (\hbox {H}_{2}\hbox {O})_{2}\). The metal complexes can act as hydrogen chloride scavengers, UV absorbers, peroxide decomposers and also as radical scavengers to enhance PVC photostability.

Photodegradation and Photostabilization of Poly(3-Hydroxybutyrate)

The present work is concerned with the photodegradation and photostabilization of poly(3-hydroxybutyrate) (PHB) biopolymer. Two commercial grades of PHB were investigated, containing of 4.0% and 6.2% of hydroxyvalerate (HV) comonomer, named PHB1 and PHB2, respectively. Injection moulded specimens were exposed to ultraviolet radiation (UV-A) in the laboratory for periods of up to 12 weeks and then characterized by tensile testing, surface appearance, size exclusion chromatography (SEC), and scanning electron microscopy (SEM). The exposure to UV radiation caused great damaged on the surface color, reduction of molecular size and mechanical properties. The effects were more pronounced on PHB2, probably due a lighter surface color and less packed macromolecular structure which facilitates the transmission of light throughout the samples. Specimens of PHB1 were also injected with the addition of a UV absorber and antioxidant, resulting in a higher UV stability of PHB, as shown by a low reduction in molar mass and better mechanical properties.

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.

Photochemical Stability and Photostabilizing Efficiency of Poly(methyl methacrylate) Based on 2-(6-Methoxynaphthalen-2-yl)propanoate Metal Ion Complexes

The photostabilization of poly(methyl methacrylate) (PMMA) films having 2-(6-methoxynaphthalen-2-yl)propanoate and Sn(II), Ni(II), Zn(II) and Cu(II) complexes was investigated. The production of PMMA films containing such complexes (0.5% by weight) was carried out by the casting method using chloroform. The photostabilization activities of the compounds were determined by monitoring the hydroxyl index with irradiation time. The quantum yield of the chain scission (Φcs) for the complexes in PMMA films and the changes in the viscosity average molecular weight of PMMA with irradiation time were evaluated. The rate of photostabilization for PMMA in the presence of the additives was found to follow the order NiL2 &gt; CuL2 &gt; ZnL2 &gt; SnL2 (L, ligand). Depending on the structure of the additive, such as a peroxide decomposer, UV absorption or a radical scavenger for the photostabilizer, several mechanisms are suggested.

Study the Rate Constant of Photostabilization of PVC in Presence of Schiff’s Bases of Sulphamethoxazole

The photostabilization of poly (vinyl chloride) (PVC) films by Sulphamethoxazole Schiff's bases compounds was investigated. The PVC films containing concentration of compounds 0.5% by weight were produced by casting method from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by calculating the photodegradation rate constant for photostabilizer (kd). The stabilizing efficiency of sulphamethoxazole–Schiff’s base derivatives is attributed to the replacement of the labile chlorine atoms on the PVC chains by a relatively more stable moiety of the organic stabilizer.

Photostabilization of Poly (Vinyl Chloride) by Some Schiff Base Derivedfrom 2-amino pyridine

In this paper, Schiff bases (1-6) were prepared and synthesized by condensing aromatic aldehydes (benzaldehyde, salicylaldehyde,-methoxylbenzaldehyde, -hydroxybenzaldehyde, furfural and isatin) with 2-amino pyridine. Spectrophotometric (FTIR) and (UV.VIS) and elemental analysis (CHN) techniques have been employed for the characterization of the additives. All the additives were used as photostabilizer for poly (vinylchloride). The rate of photodegradation and photostabilization of PVC films (40µm) were monitored with irradiation time by measuring the carbonyl (Ico) and polyene (Ipo) indices values (the concentration of additives kept constant at 0.3% wt/wt). The light of wave length 313nm is used for irradiation of polymer films at temperature around 40 o C. The effect of additives concentration range from (0.1-0.5) wt% on the rate of photodegradation and photostabilization was also monitored for PVC films. The rates increase when additives concentration is increased. The effect of film thickness is also studied and results show that increasing film thickness will decrease the rate of photo degradation in the following sequence: [2] > [5] > [4] > [6] > [3] > [1]> PVC According to the experimental results several mechanisms were suggested depending on the structure of the additive.

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.

Microwave Synthesis of Some New 1,3-Oxazepine Compounds as Photostabilizing Additives for Pmma Films

The work presented in the current research is concerned with the synthesis of four new compounds containing 1,3-oxazepine and 1,3,4-oxadiazole [1-4] by microwave assisted organic synthesis method through the condensation reaction of 2-[4-(arylidene) phenyl-1,3,4-oxadiazole-5thiole] with maleic anhydride under variable microwave power (180, 510) watt. The structure of the synthesized compounds was characterized using available spectroscopic methods (H 1 -NMR, FTIR) and the results obtained are agreement with the proposed structures assigned to these compounds. The photostabilization of poly (methyl methacrylate) PMMA films by of 1,3-Oxazepine compounds [1-4] was investigated. The PMMA films containing concentration of [1-4] 0.5% by weight were produced by the casting method from chloroform solvent. The photostabilization activities of these compounds were determined by monitoring the hydroxyl index with irradiation time. The changes in viscosity average molecular weight of PMMA with irradiation time were also tracked (using benzene as a solvent). The quantum yield of the chain scission (Φcs) of these compounds in PMMA films was evaluated and found to range between 4.2010 -5 and 8.7610 -5 . Results obtained showed that the rate of photostabilization of PMMA in the presence of the additive followed the trend: [1] > [2]> [3]> [4] 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.