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

2021 ◽  
Vol 11 (6) ◽  
pp. 2853
Author(s):  
Ahmed Ahmed ◽  
Gamal A. El-Hiti ◽  
Angham G. Hadi ◽  
Dina S. Ahmed ◽  
Mohammed A. Baashen ◽  
...  
Keyword(s):  
Thin Films ◽  
Infrared Spectra ◽  
Ultraviolet Irradiation ◽  
Mefenamic Acid ◽  
Chemical Degradation ◽  
Chemical Structures ◽  
Poly Vinyl Chloride ◽  
Tin Complexes ◽  
Surface Changes

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.

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

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2923
Author(s):  
Baneen Salam ◽  
Gamal A. El-Hiti ◽  
Muna Bufaroosha ◽  
Dina S. Ahmed ◽  
Ahmed Ahmed ◽  
...  
Keyword(s):  
Weight Loss ◽  
Infrared Spectroscopy ◽  
Surface Morphology ◽  
Vinyl Chloride ◽  
Poly Vinyl Chloride ◽  
Phenyl Rings ◽  
Tin Complexes ◽  
High Yields ◽  
Loss Determination ◽  
Surface Changes

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.

scholarly journals Long-Term Effect of Ultraviolet Irradiation on Poly(vinyl chloride) Films Containing Naproxen Diorganotin(IV) Complexes

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2396 ◽  
Author(s):  
Angham G. Hadi ◽  
Emad Yousif ◽  
Gamal A. El-Hiti ◽  
Dina S. Ahmed ◽  
Khudheyer Jawad ◽  
...  
Keyword(s):  
Weight Loss ◽  
Vinyl Chloride ◽  
Ultraviolet Irradiation ◽  
Term Effect ◽  
Direct Absorption ◽  
Poly Vinyl Chloride ◽  
Long Term Effect ◽  
Polymeric Chains ◽  
Surface Morphologies

As poly(vinyl chloride) (PVC) photodegrades with long-term exposure to ultraviolet radiation, it is desirable to develop methods that enhance the photostability of PVC. In this study, new aromatic-rich diorganotin(IV) complexes were tested as photostabilizers in PVC films. The diorganotin(IV) complexes were synthesized in 79–86% yields by reacting excess naproxen with tin(IV) chlorides. PVC films containing 0.5 wt % diorganotin(IV) complexes were irradiated with ultraviolet light for up to 300 h, and changes within the films were monitored using the weight loss and the formation of specific functional groups (hydroxyl, carbonyl, and polyene). In addition, changes in the surface morphologies of the films were investigated. The diorganotin(IV) complexes enhanced the photostability of PVC, as the weight loss and surface roughness were much lower in the films with additives than in the blank film. Notably, the dimethyltin(IV) complex was the most efficient photostabilizer. The polymeric film containing this complex exhibited a morphology of regularly distributed hexagonal pores, with a honeycomb-like structure—possibly due to cross-linking and interactions between the additive and the polymeric chains. Various mechanisms, including direct absorption of ultraviolet irradiation, radical or hydrogen chloride scavenging, and polymer chain coordination, could explain how the diorganotin(IV) complexes stabilize PVC against photodegradation.

scholarly journals Protection of Poly(Vinyl Chloride) Films against Photodegradation Using Various Valsartan Tin Complexes

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 969 ◽  
Author(s):  
Alaa Mohammed ◽  
Gamal A. El-Hiti ◽  
Emad Yousif ◽  
Ahmed A. Ahmed ◽  
Dina S. Ahmed ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Polymeric Materials ◽  
Incident Radiation ◽  
Industrial Applications ◽  
Polymeric Films ◽  
Polymeric Chain ◽  
Molecular Weight Determination ◽  
Chemical Structures ◽  
Poly Vinyl Chloride ◽  
Tin Complexes

Poly(vinyl chloride) is a common plastic that is widely used in many industrial applications. Poly(vinyl chloride) is mixed with additives to improve its mechanical and physical properties and to enable its use in harsh environments. Herein, to protect poly(vinyl chloride) films against photoirradiation with ultraviolet light, a number of tin complexes containing valsartan were synthesized and their chemical structures were established. Fourier-transform infrared spectroscopy, weight loss, and molecular weight determination showed that the non-desirable changes were lower in the films containing the tin complexes than for the blank polymeric films. Analysis of the surface morphology of the irradiated polymeric materials showed that the films containing additives were less rough than the irradiated blank film. The tin complexes protected the poly(vinyl chloride) films against irradiation, where the complexes with high aromaticity were particularly effective. The additives act as primary and secondary stabilizers that absorb the incident radiation and slowly remit it to the polymeric chain as heat energy over time at a harmless level.

scholarly journals Synthesis of Carvedilol–Organotin Complexes and Their Effects on Reducing Photodegradation of Poly(Vinyl Chloride)

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 500 ◽  
Author(s):  
Omar G. Mousa ◽  
Gamal A. El‐Hiti ◽  
Mohammed A. Baashen ◽  
Muna Bufaroosha ◽  
Ahmed Ahmed ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Vinyl Chloride ◽  
Uv Irradiation ◽  
Chemical Structure ◽  
Uv Light ◽  
Poly Vinyl Chloride ◽  
Pvc Film ◽  
Tin Complexes

Poly(vinyl chloride) (PVC) undergoes photodegradation induced by ultraviolet (UV) irradiation; therefore, for outdoor applications, its photostability should be enhanced through the use of additives. Several carvedilol tin complexes were synthesized, characterized and mixed with PVC to produce thin films. These films were irradiated at 25 °C with a UV light (λ = 313 nm) for up to 300 h. The reduction in weight and changes in chemical structure and surface morphology of the PVC films were monitored. The films containing synthesized complexes showed less undesirable changes than the pure PVC film. Organotin with a high content of aromatics was particularly efficient in inhibiting photodegradation of PVC. The carvedilol tin complexes both absorbed UV light and scavenged radicals, hydrochloride, and peroxides and, therefore, photostabilized PVC.

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

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3264
Author(s):  
Anaheed A. Yaseen ◽  
Emad Yousif ◽  
Emaad T. B. Al-Tikrity ◽  
Gamal A. El-Hiti ◽  
Benson M. Kariuki ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Vinyl Chloride ◽  
Photo Oxidation ◽  
Poly Vinyl Chloride ◽  
Stabilizing Effect ◽  
Tin Complexes ◽  
The One ◽  
Harsh Conditions

Poly(vinyl chloride) (PVC) is an important synthetic plastic that is produced in large quantities (millions of tons) annually. Additives to PVC are necessary to allow its use in many applications, particularly in harsh conditions. In regard to this, investigation of the synthesis of trimethoprim–tin complexes and their use as PVC additives is reported. Trimethoprim–tin complexes were obtained from the reaction of trimethoprim and tin chlorides using simple procedures. Trimethoprim–tin complexes (0.5% by weight) were added to PVC to produce homogenous mixtures and thin films were made. The effect of ultraviolet irradiation on the surface and properties of the PVC films was investigated. The level of both photodecomposition and photo-oxidation of PVC films containing trimethoprim–tin complexes was observed to be lower than for the blank film. The effectiveness of tin complexes as PVC photostabilizers reflects the aromaticity of the additives. The complex containing three phenyl groups attached to the tin cation showed the most stabilizing effect on PVC. The complex containing two phenyl groups was next, with the one containing butyl substituents resulting in the least stabilization of PVC. A number of mechanisms have been proposed to explain the role of the synthesized complexes in PVC photostabilization.

scholarly journals Tin Complexes of 4-(Benzylideneamino)benzenesulfonamide: Synthesis, Structure Elucidation and Their Efficiency as PVC Photostabilizers

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2434
Author(s):  
Hassan Ghani ◽  
Emad Yousif ◽  
Dina S. Ahmed ◽  
Benson M. Kariuki ◽  
Gamal A. El-Hiti
Keyword(s):  
Vinyl Chloride ◽  
Structure Elucidation ◽  
Poly Vinyl Chloride ◽  
Polymeric Chains ◽  
Process Decomposition ◽  
Stabilizing Effect ◽  
Surface Alteration ◽  
Tin Complexes ◽  
High Yields ◽  
Harsh Conditions

Poly(vinyl chloride) (PVC) suffers from photo-xidation and photodegradation when exposed to harsh conditions. Application of PVC thus relies on the development of ever more efficient photostabilizers. The current research reports the synthesis of new complexes of tin and their assessment as poly(vinyl chloride) photostabilizers. The three new complexes were obtained in high yields from reaction of 4-(benzylideneamino)benzenesulfonamide and tin chlorides. Their structures were elucidated using different tools. The complexes were mixed with poly(vinyl chloride) at a very low concentration and thin films were made from the blends. The effectiveness of the tin complexes as photostabilizers has been established using a variety of methods. The new tin complexes led to a decrease in weight loss, formation of small residues, molecular weight depression, and surface alteration of poly(vinyl chloride) after irradiation. The additives act by absorption of ultraviolet light, removal the active chlorine produced through a dehydrochlorination process, decomposition of peroxides, and coordination with the polymeric chains. The triphenyltin complex showed the greatest stabilizing effect against PVC photodegradation as a result of its high aromaticity.

scholarly journals Improvement of the long-term stability of ZnSnO thin film transistors by tungsten incorporation using a solution-process method

RSC Advances ◽  
2018 ◽  
Vol 8 (37) ◽  
pp. 20990-20995 ◽  
Author(s):  
Xiang Yang ◽  
Shu Jiang ◽  
Jun Li ◽  
Jian-Hua Zhang ◽  
Xi-Feng Li
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thin Film Transistors ◽  
Solution Process ◽  
Solution Technique ◽  
Term Stability ◽  
Long Term Stability ◽  
Process Method

In this paper, W-doped ZnSnO (WZTO) thin films and TFT devices are successfully fabricated by a wet-solution technique.

ASSESSMENT OF ELECTRICALLY ACTIVE DEFECT PARAMETERS IN POLYARYLENPHTHALIDES

2021 ◽  
Vol 0 (1) ◽  
pp. 75-80
Author(s):  
A.V. MOSHELEV ◽  
◽  
A.F. PONOMAREV ◽  
S.N. SALAZKIN ◽  
V.V. SHAPOSHNIKOVA ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermally Stimulated Current ◽  
Chemical Structures ◽  
Active Defect ◽  
Trapping State

Trapping state parameters in thin films of polyarylenephthalide polymers with different chemical structures were studied using the thermally stimulated current (TSC) method. As the objects of our research we used polyarylenephthalide polymers - polydiphenylphthalide (PDP) [1] and phthalide-based statistical co-polyarylene ether ketones (co-PAEK) [2]. It was revealed in the paper that the energy of trapping state activation essentially depends on the concentration of phhalide-containing fragments.

Mechanical Properties of Epoxy Adhesive Under Thermal Aging and Their Chemical Degradation Behavior

2021 ◽  
Vol 21 (8) ◽  
pp. 4444-4449
Author(s):  
Bongjin Chung ◽  
Shin Sungchul ◽  
Jaeho Shim ◽  
Seongwoo Ryu
Keyword(s):  
Mechanical Properties ◽  
Thermal Aging ◽  
Photoelectron Spectroscopy ◽  
Thermal Exposure ◽  
Chain Scission ◽  
Epoxy Adhesive ◽  
Chemical Degradation ◽  
Adhesive Properties ◽  
Noticeable Reduction

Epoxy adhesive was analyzed under long term thermal aging and mechanical properties and chemical degradation were observed by X-ray photoelectron spectroscopy (XPS). Long term thermal exposure of epoxy causes a noticeable reduction in adhesive properties. We developed a predictive model of temperature and time dependent aging. The temperature dependent aging behavior of epoxy adhesive shows good agreement with conventional Arrhenius equations. Using XPS analysis, we also discovered a correlation between chemical degradation and the adhesive properties. Decay of C–C bonding ratio induced chain-scission of epoxy adhesive; increase of total numbers of C–O and C═O induced oxidation of epoxy adhesive during thermal exposure.

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