scholarly journals New Solvent for Polyamide 66 and Its Use for Preparing a Single-Polymer Composite-Coated Fabric

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Mostafa Jabbari ◽  
Mikael Skrifvars ◽  
Dan Åkesson ◽  
Mohammad J. Taherzadeh
Keyword(s):  
Calcium Chloride ◽  
Solvent System ◽  
Polyamide 66 ◽  
Coated Fabric ◽  
Viscous Solution ◽  
Ph Decrease ◽  
The One ◽  
Engineering Polymers ◽  
Viscous Solutions ◽  
Water Gas

Polyamides (PAs) are one of the most important engineering polymers; however, the difficulty in dissolving them hinders their applications. Formic acid (FA) is the most common solvent for PAs, but it has industrial limitations. In this contribution, we proposed a new solvent system for PAs by replacing a portion of the FA with urea and calcium chloride (FAUCa). Urea imparts the hydrogen bonding and calcium ion from the calcium chloride, as a Lewis acid was added to the system to compensate for the pH decrease due to the addition of urea. The results showed that the proposed solvent (FAUCa) could readily dissolve PAs, resulting in a less decrease in the mechanical properties during the dissolution. The composite prepared using the FAUCa has almost the same properties as the one prepared using the FA solution. The solution was applied on a polyamide 66 fabric to make an all-polyamide composite-coated fabric, which then was characterized. The FAUCa solution had a higher viscosity than the one prepared using the neat FA solvent, which can be an advantage in the applications which need higher viscosity like preparing the all-polyamide composite-coated fabric. A more viscous solution makes a denser coating which will increase the water /gas tightness. In conclusion, using the FAUCa solvent has two merits: (1) replacement of 40% of the FA with less harmful and environmentally friendly chemicals and (2) enabling for the preparation of more viscous solutions, which makes a denser coating.

scholarly journals New Solvent for Polyamide 66 and its use for Preparing Single-Polymer Composite Coated-Fabric

2018 ◽  
Author(s):  
Mostafa Jabbari ◽  
Parviz Rashidi Ranjbar ◽  
mikael skrifvars ◽  
Dan Åkesson ◽  
Mohammad J. Taherzadeh
Keyword(s):  
Calcium Chloride ◽  
Calcium Ion ◽  
Solvent System ◽  
Polyamide 66 ◽  
Coated Fabric ◽  
Ph Decrease ◽  
The One ◽  
Engineering Polymers ◽  
Water Gas ◽  
Gas Tightness

Polyamides (PAs) are one of the most important engineering polymers; however, the difficulty in dissolving them hinders their applications. Formic acid (FA) is the most common solvent for PAs, but it has industrial limitations. In this contribution, we proposed a new solvent system for PAs by replacing a portion of the FA with urea and calcium chloride (FAUCa). Urea imparts the hydrogen bonding and calcium ion from the calcium chloride, as a Lewis acid was added to the system to compensate for the pH decrease due to the addition of urea. The results showed that the proposed solvent (FAUCa) could readily dissolve PAs, resulting in less decrease in the mechanical properties during the dissolution. The composite prepared using the FAUCa has almost the same properties like the one prepared using the FA solution. The solution was applied on a polyamide 66 fabric to make an all-polyamide composite coated-fabric, which then was characterized. The FAUCa solution had a higher viscosity than the one prepared using the neat FA solvent, which can be an advantage in the applications which needs higher viscosity like preparing the all-polyamide composite coated-fabric. A more viscouse solution makes a denser coating which will increase the water-/gas-tightness. In conclusion, using the FAUCa solvent has two merits: 1. replacement of 40 % of the FA with less harmful and environmentally-friendly chemicals and 2. enabling for the preparation of more viscouse solutions, which makes denser coating.

Rheological Studies of an Injectable Radiopaque Hydrogel for Embolization of Abdominal Aortic Aneurysms

2011 ◽  
Vol 409 ◽  
pp. 129-135 ◽  
Author(s):  
Ahmed Fatimi ◽  
Jean Michel Coutu ◽  
Guy Cloutier ◽  
Sophie Lerouge
Keyword(s):  
Gelation Time ◽  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Invasive Treatment ◽  
Chitosan Hydrogel ◽  
X Ray ◽  
Slowing Down ◽  
Abdominal Aortic ◽  
Viscous Solution ◽  
Viscous Solutions

Several embolizing agents have been tested for minimally invasive treatment of intracranial aneurysms, and more recently to prevent or treat persistent blood flow (endoleaks) in abdominal aortic aneurysms. However, frequent recurrence of endoleaks was seen in most studies, suggesting that current embolization agents are not satisfying yet. Here we report rheological studies of a radiopaque chitosan hydrogel as an embolizing agent. The aim is to provide an agent that would be visible during x-ray based guided interventions. In this study, a commercial contrast agent (iopamidol) was associated to chitosan at different concentrations and its influence on the rheological behavior of chitosan thermogel was evaluated. The resulting hydrogels have a homogenous coherent structure. The addition of iopamidol leaded to an initially more viscous solution. To have a good visibility of hydrogel via x-ray, an optimum iopamidol concentration of 20% v/v was chosen. The addition of 20% v/v iopamidol increased the gelation time. The use of a high βGP concentration constitutes a solution to overcome the slowing down of gelation by 20% v/v iopamidol. Formulations containing around 16-20% βGP provides viscous solutions which rapidly gel and could be promising injectable radiopaque hydrogels for embolization.

Determination of Geographical Origin of Spices. I. Cassia and Cinnamon by Thin Layer Chromatography

1967 ◽  
Vol 50 (4) ◽  
pp. 852-856
Author(s):  
William A Voelker ◽  
Jean N Skarzynski ◽  
William H Stahl
Keyword(s):  
Thin Layer ◽  
Ethyl Acetate ◽  
Geographical Origin ◽  
Raw Materials ◽  
Screening Method ◽  
Solvent System ◽  
Dimensional System ◽  
Quality Control Tool ◽  
Ceylon Cinnamon ◽  
The One

Abstract A thin layer chromatographic method has been devised to differentiate the geographical origin of cinnamons (cassias). For the one-dimensional screening method, benzene-ethyl acetate-glacial acetic acid (90: 10:1, v/v/v), was used as the solvent system. The two-dimensional system first used hexane-acetone (85:15) and then benzene- ethyl acetate (85:15). The following products were differentiated on the basis of fluorescing spots, some spots common to all and some spots unique: Saigon cassia, Batavia cassia, Korintji cassia, Ceylon cinnamon, and Seychelles cinnamon. The technique is primarily designed as a quality control tool to evaluate incoming shipments of raw materials. However, it can he used to determine composition of unknown mixtures of the ground cinnamons. The technique permits judgment within ± 2 0 % of one type in a mixture

Effect of Calcium Chloride on Dyeing Property of Polyamide 66 Based on Reactive Anthraquinone Dyes with Different Structure

2019 ◽  
Vol 20 (10) ◽  
pp. 2140-2145
Author(s):  
Hongjuan Zhang ◽  
Aiqin Gao ◽  
Kongliang Xie ◽  
Aiqin Hou
Keyword(s):  
Calcium Chloride ◽  
Polyamide 66 ◽  
Dyeing Property ◽  
Anthraquinone Dyes

Complex-formation between triphosphoinositide and experimental allergic encephalitogenic protein

1969 ◽  
Vol 111 (5) ◽  
pp. 637-646 ◽  
Author(s):  
F. B. Palmer ◽  
R. M. C. Dawson
Keyword(s):  
Sodium Chloride ◽  
Calcium Chloride ◽  
Complex I ◽  
Solvent System ◽  
Constant Composition ◽  
Complex Ii ◽  
Acidic Phospholipids ◽  
Chloroform Methanol ◽  
Experimental Allergic

1. Reactions between triphosphoinositide and the basic experimental allergic encephalitogenic (EAE) protein were examined in aqueous solution and in a biphasic solvent system (chloroform–methanol–water, 8:4:3, by vol.). 2. In the absence of salt an insoluble complex (I) is formed containing triphosphoinositide and EAE protein in proportions that represent complete neutralization of lipid and protein at the pH concerned. 3. In the presence of a low concentration (0·05m) of sodium chloride an insoluble positively charged complex (II) forms. It contains triphosphoinositide and EAE protein in a lower concentration ratio than complex I. This complex, which has a constant composition between pH7·5 and pH10, can take up additional micellar triphosphoinositide producing complex I, which can then be solubilized by excess of triphosphoinositide. 4. The complexes are dissociated by more concentrated sodium chloride solutions and low concentrations of calcium chloride, suggesting that they are largely stabilized by electrostatic bonds. The protein recovered after dissociation is immunologically active and has the same electrophoretic mobility as the original. 5. Water-insoluble ternary complexes containing triphosphoinositide, EAE protein and large amounts of phosphatidylcholine can be prepared. From these, chloroform–methanol (2:1, v/v) extracts only phosphatidylcholine. 6. An insoluble ternary complex of Ca2+ ion, EAE protein and triphosphoinositide can be prepared by adding calcium chloride to a complex I preparation solubilized by excess of triphosphoinositide. 7. EAE protein will also form complexes with other acidic phospholipids, e.g. phosphatidic acid, phosphatidylserine and phosphatidylinositol, but not with phosphatidylcholine or phosphatidylethanolamine. The phosphatidylinositol and phosphatidylserine complexes are chloroform soluble, i.e. proteolipids. 8. The possibility that complexes between EAE protein and acidic phospholipids occur in vivo is discussed. Triphosphoinositide and EAE protein occur in ox brain myelin in approximately the same concentration ratios as they do in complex II, formed at physiological salt concentration and pH.

scholarly journals A FILTRABLE VIRUS, THE CAUSE OF INFECTIOUS LARYNGOTRACHEITIS OF CHICKENS

1931 ◽  
Vol 54 (6) ◽  
pp. 809-816 ◽  
Author(s):  
J. R. Beach
Keyword(s):  
New Jersey ◽  
Calcium Chloride ◽  
Etiological Agent ◽  
Infectious Laryngotracheitis ◽  
The One

1. Experiments have shown that tracheal exudate from two strains of laryngotracheitis of chickens from New Jersey and two from California when suspended in bouillon and passed through Berkefeld V filters will produce the disease. Two of six Berkefeld N filters allowed the etiological agent to pass, whereas four did not. Attempts to produce the disease with Seitz filtrates were unsuccessful. These results demonstrate that laryngotracheitis is caused by a filtrable virus that because of its size or some other property does not pass readily through the finer filters. 2. It has been shown that the sera from fowls that have recovered from an infection with one of the New Jersey viruses will neutralize the same strain and also the one California strain tested. In order to demonstrate neutralization conclusively it was necessary to titrate samples of dried virus and in the tests to use approximately ten infecting doses. 3. The virus dried over calcium chloride for 10 days and then stored in the refrigerator for 60 days produced disease. Kept over calcium chloride for a month it was still active and when dried by Swift's method it remained alive for 5 months.

scholarly journals A study of catalytic actions at solid surfaces. X. -The interaction of carbon monoxide and hydrogen as conditioned by nickel at relatively low temperatures. -A practical synthesis of methane

1923 ◽  
Vol 103 (720) ◽  
pp. 25-34 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Low Temperatures ◽  
Solid Surfaces ◽  
The Other ◽  
Theoretical Interest ◽  
Primary Object ◽  
Pure Methane ◽  
Practical Synthesis ◽  
The One ◽  
Water Gas

The investigation described in this communication had for its primary object the production of formaldehyde or methyl alcohol. In this aim we have been so far unsuccessful, but our results have led to the discovery of an action, Apart from theoretical interest the method would appear to have important technical possibilities, either as a means of producing pure methane is formed from water-gas than by other methods. In order to make clear the course of the action about to be described it will be well briefly to enumerate some of the known interactions of carbon monoxide and hydrogen on the one hand, and of the former gas and steam on the other.

scholarly journals Effect of Atmospheric Cold Plasma Treatment on the Adhesion and Tribological Properties of Polyamide 66 and Poly(Tetrafluoroethylene)

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 658 ◽  
Author(s):  
Zoltán Károly ◽  
Gábor Kalácska ◽  
Jacob Sukumaran ◽  
Dieter Fauconnier ◽  
Ádám Kalácska ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Tribological Properties ◽  
Cold Plasma ◽  
Polymer Surface ◽  
Surface Barrier ◽  
Polyamide 66 ◽  
Atmospheric Air ◽  
Engineering Polymers ◽  
Steel Joints ◽  
Barrier Discharges

The surfaces of two engineering polymers including polyamide 66 (PA66) and polytetrafluoroethylene (PTFE) were treated by diffuse coplanar surface barrier discharges in atmospheric air. We found that plasma treatment improved the adhesion of PA66 for either polymer/polymer or polymer/steel joints, however, it was selective for the investigated adhesive agents. For PTFE the adhesion was unaltered for plasma treatment regardless the type of used adhesive. Tribological properties were slightly improved for PA66, too. Both the friction coefficient and wear decreased. Significant changes, again, could not be detected for PTFE. The occurred variation in the adhesion and tribology was discussed on the basis of the occurred changes in surface chemistry, wettability and topography of the polymer surface.

Fundamental viscous solutions or 'transient oseenlets’ associated with a body manoeuvring in a viscous fluid

1992 ◽  
Vol 438 (1904) ◽  
pp. 447-466 ◽  
Keyword(s):  
Viscous Fluid ◽  
Three Dimensional ◽  
Axial Flow ◽  
Fundamental Solutions ◽  
Theoretical Development ◽  
Velocity Flow ◽  
Viscous Solution ◽  
Viscous Boundary ◽  
Singularity Distribution ◽  
Viscous Solutions

A viscous boundary element method involving a convolution-integral formulation is developed to determine directly the fluid actions and velocity flow field associated with a body manoeuvring in a viscous fluid. The proposed general approach is analogous to a potential flow singularity distribution panel method with the singularity replaced by a fundamental viscous solution. From the developed nonlinear mathematical model based on an integral identity relation, it is seen that the Oseen equation, its variant or modified form is central to the theoretical development of the fundamental viscous solution. Analytical expressions are presented for the fundamental solutions (or transient oseenlets) appropriate to two-dimensional and three-dimensional steady, and unsteady (transient) manoeuvring problems involving prescribed translational, rotational and their combined motions. The examples considered, and hence the fundamental viscous solutions, relate to model towing tank experiments (i.e. steady state, rotating arm, planar motion mechanism oscillatory tests, etc.) used extensively to derive fluid action data on manoeuvring ships and submersibles. Examples of combined translational and rotational motions are investigated and these relate to an elementary idealization of a propeller rotating in an axial flow and an idealization of a body moving ahead with parasitic oscillatory roll motion. The predicted fluid flow patterns associated with the various fundamental solutions are presented and these clearly illustrate the generation, shedding and decay of vortices in the wakes.

scholarly journals Controlled Release of TBH Herbicide Encapsulated on Ca-ALG Microparticles: Leaching and Phytointoxication Plants

2019 ◽  
Vol 37 ◽  
Author(s):  
D.F. MACEDO ◽  
S.M. DOURADO JR. ◽  
E.S. NUNES ◽  
R.P. MARQUES ◽  
J.A. MORETO
Keyword(s):  
Aqueous Solution ◽  
Controlled Release ◽  
Soil Contamination ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Calcium Alginate ◽  
Dry Mass ◽  
Leaching Process ◽  
The One

ABSTRACT: The aim of this work was to demonstrate a detailed study of the controlled release of the herbicide Tebuthiuron (TBH) encapsulated in microparticles of calcium alginate (Ca-ALG), to evaluate the phytotoxicity in different concentrations of herbicide (4, 6 and 8 g L-1), and their correlation with the depth of leaching using bioindicator plants. The Ca-ALG microparticles were prepared from the crosslinking of sodium alginate by Ca++ containing varied amounts of TBH supplied in calcium chloride (CaCl2) aqueous solution. The results showed that TBH herbicide, when encapsulated, leached to shallow depths relative to the conventional, non-encapsulated herbicide (which moved to a depth of 40-50 cm). The concentration of 4 g L-1 was the one that leached most in the PVC columns, but its mobility did not exceed 30 cm of depth. The results of the dry mass corroborated with the phytotoxicity results of the bioindicator plants, evidencing the mobility of the conventional herbicide in the soil at depths around 40 and 50 cm, while the herbicide encapsulated in the Ca-ALG microparticles did not show leaching beyond 20 -30 cm deep. The encapsulation of TBH in Ca-ALG microparticles can thus be considered as a more eco-friendly technology, reducing the leaching process and consequently soil contamination.

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