scholarly journals Evaluation of the Stability of Polymeric Materials Exposed to Palm Biodiesel and Biodiesel–Organic Acid Blends

Polymers ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 511 ◽  
Author(s):  
Libia Baena ◽  
Ernesto Zuleta ◽  
Jorge Calderón
Keyword(s):  
Organic Acid ◽  
Polymeric Materials ◽  
The Stability

scholarly journals Cellulose Acetate Fabrics Loaded with Rhodamine B Hydrazide for Optical Detection of Cu(II)

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3751
Author(s):  
Rania E. Morsi ◽  
Moataz Elsawy ◽  
Ilse Manet ◽  
Barbara Ventura
Keyword(s):  
Porous Structure ◽  
Cellulose Acetate ◽  
Rhodamine B ◽  
Polymeric Materials ◽  
Emission Analysis ◽  
Absorption And Emission ◽  
Sensing Applications ◽  
Phase Inversion Technique ◽  
The Stability ◽  
Rhodamine B Hydrazide

In this work, different materials were fabricated from cellulose acetate, loaded with rhodamine B hydrazide and tested as Cu(II) optical sensor. We prepared membranes displaying a sub-micron porous structure using the phase inversion technique, clusters of fibers with varying diameter depending on the preparation procedure using electrospinning, and casted films presenting a smooth non porous structure. Loading of rhodamine B hydrazide on the fabrics after their production was found to be the best procedure to ensure the stability of the dye in the polymeric materials. Absorption and emission analysis of the solid substrates revealed the presence of the dye on the porous fabrics and allowed to choose the most suited materials and loading conditions to test their response towards Cu(II) ions. Reaction of the loaded rhodamine B hydrazide with Cu(II) was confirmed by absorption and emission spectroscopies and by confocal fluorescence imaging, through detection of the product rhodamine B. The results point to promising sensing applications of the prepared composite materials.

Effects of HTCA on Microstructure and Surface Morphology of Porous Anodic Alumina Membrane

2007 ◽  
Vol 546-549 ◽  
pp. 1141-1144
Author(s):  
Wen Jing Zhang ◽  
Yong Kang Le ◽  
Hui Wang ◽  
Bin Ou ◽  
Jian Wei Mao ◽  
...  
Keyword(s):  
Oxide Film ◽  
Organic Acid ◽  
Anodic Oxide ◽  
Honeycomb Structure ◽  
Alumina Membrane ◽  
Porous Aluminum ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Matrix ◽  
The Stability

Porous aluminum anodic oxide films fabricated by anodizing in phosphoric acid electrolyte containing organic acid were investigated by scanning electron microscope (SEM) and Atomic Force Microscopy (AFM). The results showed that the pores with circular or near elliptical honeycomb structure did not grow along the processing direction of the matrix and present an optimum ordering. It also indicated that the adding of the organic acid reduces the defects during the oxide film growing process and increases the stability and uniformity of the oxide film, and the thickness of the oxide film is significantly increased.

scholarly journals Application of Complex Chitosan Hydrogels Added With Canola Oil in Partial Substitution of Cocoa Butter in Dark Chocolate

2020 ◽  
Vol 4 ◽  
Author(s):  
Andres Silvestre Gallegos Soto ◽  
Renata Santos Rabelo ◽  
Eliana Marcela Vélez-Erazo ◽  
Paulo Túlio de Souza Silveira ◽  
Priscilla Efraim ◽  
...  
Keyword(s):  
Cocoa Butter ◽  
Canola Oil ◽  
Polymer Concentration ◽  
Saturated Fat ◽  
Polymeric Materials ◽  
Fat Content ◽  
Dark Chocolate ◽  
Partial Substitution ◽  
Retention Capacity ◽  
The Stability

The complexation of polymeric materials can be an alternative to trapping oil in a physical network for formulating foods with reduced saturated fat content. In this research, we have evaluated the use of different polymer ratios of Sodium Alginate (ALG), Carrageenan predominance iota (CR1) and Carrageenan predominance kappa (CR2) complexed with Chitosan (CHI) at a fixed polymer concentration (2% w/v) to formulate complex hydrogels and assess their oil holding capacity. The objective was to determine the polymer ratios of CHI to anionic polysaccharides (75:25, 50:50, and 25:75), determining the oil retention capacity in different ratios, and how this can affect the stability, microstructure and rheology of to produce low saturated chocolate with trapped canola oil. The stability of the hydrogels was characterized, considering the water retention and retention of canola oil in polysaccharides complexes. The more stable system was the hydrogel CHI:CR2 in a polymer ratio of 25:75. This formulation, when added of 20% of canola oil presented an apparent viscosity of 0.631 Pa.s at 300 s−1, and its use as replacer of saturated fat allowed the production of dark chocolate with 16% reduction in fat content and 80% of added cocoa butter. Stability studies showed that polysaccharides complexes network can retain the edible oil in chocolate formulation for 60 days. It has been proven that polysaccharides complexes can be incorporated to partially replace the fatty phase in chocolates without considerable changes in relevant characteristics as consumer acceptance evaluated by sensory tests and rheological properties.

scholarly journals Interpretation of CBR Test Consequences for Subgrade Soil Preserved Through Geo-Grid

2019 ◽  
Vol 9 (1) ◽  
pp. 3636-3640
Keyword(s):  
Moisture Content ◽  
Polymeric Materials ◽  
Cost Effective ◽  
Soil Reinforcement ◽  
Optimum Number ◽  
Sustainable Performance ◽  
Cbr Test ◽  
Base Course ◽  
Materials Used ◽  
The Stability

The California Bearing Ratio (CBR) is a parameter for evaluation of the mechanical strength of sub grade, base course and other layers of a new carriage way. It depends on various factors and nature of soil. The service life of pavement on weaker soil sub grade is quite low due to the high compressibility and plasticity behavior of soils. Some soils possess less strength, CBR value and have high affinity to moisture content. Hence it is important to increase the strength of soil for sustainable performance of Indian roads. To increase the sub grade soil strength, geogrids are used in roads. Geogrids are cost effective polymeric materials used as soil reinforcement. It helps to increase the stability and bearing capacity of soil, enables good drainage and involves less maintenance. Increase in CBR value of the sample with use of geogrids leads to reduction in the thickness of pavement. Two soil samples are collected from the nearby construction sites. Basic tests are to be conducted on the samples to determine its engineering and index properties followed by CBR test under optimum moisture content. This paper deals with the experimental results of CBR tests on different types of sub grade soil by increasing the number of geogrid layers in each trial. This gives the optimum number of geogrid layer to attain the maximum CBR value. This paper also includes the application of CBR value in the design of flexible pavements as per IRC recommendations.

scholarly journals The preparation and characterization of structurally stable 5-coordinate polystannanes

2021 ◽  
Author(s):  
Aman U. Khan
Keyword(s):  
Good Yield ◽  
Polymeric Materials ◽  
Organotin Compounds ◽  
Tetrahedral Geometry ◽  
Molecular Weights ◽  
Trigonal Bipyramidal ◽  
Chelating Ligand ◽  
The Stability ◽  
Structurally Stable

Tetraorganotin compounds [2-(MeOCH2)C6H4]SnR3 (R = Me, n-Bu, Ph) containing a C,O-chelating ligand were prepared in good yield from the reaction of the R3SnCl and [2-(MeOCH2)C6H4]Li. Tethered organotin compounds Ph3Sn(CH2)3OC6H4R (R = Ph, H, CF3, OCH3) were prepared in good yield from the hydrostannylation reactions of the corresponding vinyl ethers with Ph3SnH. Conversion of two organotin compounds to triorganotin chlorides and diorganotin chlorides, (Ph3-nClnSn(CH2)3OC6H4R; R = H, Ph: n = 1, 2), was successfully carried out and characterisation afforded by NMR spectroscopy. X-ray crystallographic studies revealed a tetrahedral geometry for the tetraorganotin Ph3Sn(CH2)3OC6H4CF3, while five-coordinate trigonal bipyramidal structures with relatively short Sn-O (2.7-2.8 Å) interactions were observed for both mono- (Ph2ClSn(CH2)3OC6H4R; R = H, Ph) and dichloride (PhCl2Sn(CH2)3OC6H4R; R = H, Ph) species. Penta-coordinate diorganotin dichlorides containing a C,N- chelating ligand[2-(Me2NCH2)C6H4]RSnCl2 (R = Me, n-Bu, Ph) or C,O- chelating ligand [2-(MeOCH2)C6H4]RSnCl2 (R = Me, n-Bu, Ph) were prepared by treating RSnCl3 with the lithiated salts [2-(Me2NCH2)C6H4]Li and [2-(MeOCH2)C6H4]Li respectively. Organotin chlorides were successfully reduced with LiAlH4 or NaBH4 to produce novel hydrides. Catalytic dehydrocoupling of diorganotin dihydrides to yield polystannanes was explored using a variety of dehydrocoupling catalysts such as Wilkinson’s catalyst, Cp2ZrMe2 or TMEDA. In almost every instance this resulted in the formation of yellow coloured gummy polymeric materials of moderate molecular weights (Mw = 1 × 104 - 1 × 105 Da) and PDI’s (1.3-2.0). The stability of polystannanes containing tethered O or C,N- or C,O-chelating ligands was investigated in both solid and in solution using NMR and UV-Vis spectroscopies. These studies revealed an enhanced stability to ambient light in the solid state and in solution in the dark when compared to known poly(dialkyl)stannanes.

scholarly journals The preparation and characterization of structurally stable 5-coordinate polystannanes

2021 ◽  
Author(s):  
Aman U. Khan
Keyword(s):  
Good Yield ◽  
Polymeric Materials ◽  
Organotin Compounds ◽  
Tetrahedral Geometry ◽  
Molecular Weights ◽  
Trigonal Bipyramidal ◽  
Chelating Ligand ◽  
The Stability ◽  
Structurally Stable

Tetraorganotin compounds [2-(MeOCH2)C6H4]SnR3 (R = Me, n-Bu, Ph) containing a C,O-chelating ligand were prepared in good yield from the reaction of the R3SnCl and [2-(MeOCH2)C6H4]Li. Tethered organotin compounds Ph3Sn(CH2)3OC6H4R (R = Ph, H, CF3, OCH3) were prepared in good yield from the hydrostannylation reactions of the corresponding vinyl ethers with Ph3SnH. Conversion of two organotin compounds to triorganotin chlorides and diorganotin chlorides, (Ph3-nClnSn(CH2)3OC6H4R; R = H, Ph: n = 1, 2), was successfully carried out and characterisation afforded by NMR spectroscopy. X-ray crystallographic studies revealed a tetrahedral geometry for the tetraorganotin Ph3Sn(CH2)3OC6H4CF3, while five-coordinate trigonal bipyramidal structures with relatively short Sn-O (2.7-2.8 Å) interactions were observed for both mono- (Ph2ClSn(CH2)3OC6H4R; R = H, Ph) and dichloride (PhCl2Sn(CH2)3OC6H4R; R = H, Ph) species. Penta-coordinate diorganotin dichlorides containing a C,N- chelating ligand[2-(Me2NCH2)C6H4]RSnCl2 (R = Me, n-Bu, Ph) or C,O- chelating ligand [2-(MeOCH2)C6H4]RSnCl2 (R = Me, n-Bu, Ph) were prepared by treating RSnCl3 with the lithiated salts [2-(Me2NCH2)C6H4]Li and [2-(MeOCH2)C6H4]Li respectively. Organotin chlorides were successfully reduced with LiAlH4 or NaBH4 to produce novel hydrides. Catalytic dehydrocoupling of diorganotin dihydrides to yield polystannanes was explored using a variety of dehydrocoupling catalysts such as Wilkinson’s catalyst, Cp2ZrMe2 or TMEDA. In almost every instance this resulted in the formation of yellow coloured gummy polymeric materials of moderate molecular weights (Mw = 1 × 104 - 1 × 105 Da) and PDI’s (1.3-2.0). The stability of polystannanes containing tethered O or C,N- or C,O-chelating ligands was investigated in both solid and in solution using NMR and UV-Vis spectroscopies. These studies revealed an enhanced stability to ambient light in the solid state and in solution in the dark when compared to known poly(dialkyl)stannanes.

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

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3946
Author(s):  
Angham G. Hadi ◽  
Sadiq J. Baqir ◽  
Dina S. Ahmed ◽  
Gamal A. El-Hiti ◽  
Hassan Hashim ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Polymeric Materials ◽  
Polymeric Films ◽  
Harsh Environments ◽  
Spectroscopic Methods ◽  
Poly Vinyl Chloride ◽  
Tin Complexes ◽  
Ultraviolet Absorbers ◽  
The Stability ◽  
Methoxybenzoic Acid

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.

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