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2019-10-16 09:59:44
With the increasing awareness of environmental protection, more and more attention has been paid to the environmental safety of surfactants, such as the discussion on whether surfactants cause harm to environmental safety, the ecology and toxicity assessment of surfactants, etc. At the same time, many people worry that with a wide variety of daily chemical products becoming people's daily necessities, such as toothpaste, soap, tableware detergent, washing powder (agent) and all kinds of cosmetics, everyone will take a certain amount of surfactants more or less every day. Therefore, there is a growing call for the research and development of environmental friendly, non-toxic and biodegradable surfactants.
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2019-10-14 11:42:18
Flame retardants play their flame retardant role through several mechanisms, such as endothermic effect, covering effect, chain reaction inhibition, asphyxiation of non-combustible gases and so on. Most flame retardants achieve their flame retardant purposes through the interaction of several mechanisms.
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2019-10-12 10:23:47
The powder design of the flame retardant effectively ensures the content of the flame retardant and reduces the application cost. However, the mixing of powder and plastic particles may be inhomogeneous due to mechanical reasons, but the amount of flame retardant is very low, only about 4%. So the method of adding PS particles and flame retardant for several minutes, then adding talcum powder, color powder and other fillers and stirring for several minutes depends on the larger specific surface area of PS particles to distribute flame retardant evenly. If the dispersion effect is still not ideal, the method of adding mineral oils such as white oil and mechanical oil can be used to wet the surface of PS particles in the mixer first, then add flame retardant to mix for several minutes, and then add additives such as toner and talc powder to mix and disperse.
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2019-10-10 17:25:26
The additive flame retardants commonly used in some materials may decompose slightly at the processing temperature, which limits the use of some flame retardants on the one hand and the processing temperature of flame retardants on the other. Many additive flame retardants are filler type. In order to make the material reach the required flame retardant level, the amount of additive is often large, so it is difficult to disperse all additive flame retardants evenly in the polymer matrix, which may reduce some properties of the material.
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2019-10-08 17:20:43
Non-ionic surfactants have excellent electrolyte resistance, hard water resistance, and good compatibility with other types of surfactants. They have been widely used to improve the stability of dispersion systems. At present, carbon black is mainly used in non-aqueous systems, such as inks and oily coatings. As the world increasingly sees and protects the environment, more and more studies have focused on carbon black water dispersions.
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2019-09-29 08:38:33
The structure of surfactant is composed of hydrophilic group and hydrophilic group. The hydrophilicity and hydrophilicity of molecule, the morphology and molecular weight of molecule affect the properties of surfactant.
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2019-09-27 08:35:39
Surface tension method: CMC is determined by the logarithmic figure of surface tension-concentration. Specific method: Measure the surface tension of a series of surfactant solutions with different concentration, make a gamma-lgc curve, and extend the linear part on both sides of the curve turning point. The concentration of intersection point is the CMC of surfactant in the system. 2) Conductivity method: When determining cmc, the square root of concentration can be plotted by conductivity to concentration or molar conductivity to concentration. The concentration of turning point is cmc. It is limited to the determination of CMC of ionic surfactants. 3) Dye method: first, a small amount of dye was added to the surfactant solution with a higher concentration (>cmc), and the dye was dissolved in micelles, showing a certain color. Then the solution was diluted with water by titration until the color changed significantly. At this time, the concentration of the solution was cmc. 4) Turbidity method: The concentration of the sudden change point of turbidity is CMC of surfactant when the turbidity of surfactant solution with appropriate amount of hydrocarbon is observed. 5) Photodispersive method: CMC can be determined by using the mutation point in the scattered light intensity-solution concentration curve.
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2019-09-25 16:31:37
Surfactant characteristics, when a substance is added to a liquid, if it can reduce the surface tension, people call this substance has surface activity. Substances with surface activity are called surface active substances.
In terms of chemical structure, all surfactant molecules are composed of polar hydrophilic group and non-polar hydrophilic group. The hydrophilic group extends the molecule to the aqueous phase, while the hydrophilic group extends the molecule away from the aqueous phase to the oil phase, so the surfactant molecule is an amphiphilic molecule. Their hydrophilic groups are composed of alkyl groups, but their hydrophilic groups are various. Surfactants have great surface activity, so they are widely used in industrial and agricultural production and daily life for emulsification, dispersion, solubilization, wetting, foaming, washing, softening and other purposes.
The effect of nonion
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2019-09-23 09:18:11
For those unqualified products that take corrective measures (such as batch or batch unqualified products; customer complaints that cause serious impact; serious quality problems or quality accidents; faults in product development, testing and use), the organization should carefully analyze the causes and take corrective measures to eliminate the unqualified reasons. Execution, otherwise the problem of non-conformity will occur again.
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2019-09-20 15:58:29
Among the factors affecting the price of polyether amine, the share of supply and demand, product quality (product technical index), production process, supply and demand situation and original supply is more than 20%. Among them, product quality ranks first, reaching 24.56%. The influence degree of production process is 22.12%. The second factor is market supply and demand, accounting for 21.17%. Raw materials affect the price of polyether amine. The degree is 20.43%. The other share of transportation cost, import and export policy is less than 10%.
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2019-09-18 08:56:43
Polyether amine production industry is at the initial stage. From the perspective of economic cycle, the industry has the cyclical economic characteristics of the initial stage. With the gradual growth of domestic demand for polyether amine, the construction of investment projects in polyether amine production industry is accelerating. This makes the domestic polyether amine production industry stand out for the rapid growth of market capacity, the increase of investment projects, and the rapid expansion of domestic product output.
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2019-09-16 17:19:31
Amino-terminated polyether is a new material just emerging in the ninth and ninth centuries of last century. It is a curing agent of epoxy resin. The resin cured by amino-terminated polyether has excellent toughness, impact resistance and low temperature resistance. Because of the low exothermic peak during curing, large epoxy resin components can be poured. Because of the low color value of the product, the cured resin can be poured plain. The casting is crystal and transparent. It is also an additive of engine fuel oil, which plays an anti-deposition role. It is also an additive of lubricating grease to improve the wear resistance of engine parts. In addition, amino-terminated polyethers are also widely used in surfactants, water-soluble coatings and binders.
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2019-09-13 17:17:32
Amino-terminated polyether is a kind of polyurethane spraying material, which can react with isocyanate to form polyurethane because the amino group is located at the bond end of polyether macromolecule. Compared with general synthetic polyurethane, the amino-terminated polyether has the following advantages: (1) the reaction between amino compound and isocyanate is faster than that of hydroxyl group, and the reaction time can be shortened. (2) Polyurea produced by the reaction of amino compounds with isocyanate. The physical properties and heat resistance of the elastomer are much better than those of the existing similar polyurethane. It has excellent stability, durability and outdoor aging resistance. It is widely used in construction under high moisture and high humidity environment, and is welcomed by users.
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2019-09-11 17:02:55
Using surfactant aqueous solution to improve the wettability of coal particles has important practical significance for the control of coal dust. Non-ionic surfactants, such as sodium o-xylene alkyl sulfonate, have been used in this field. Glanville et al. discussed various factors affecting the wetting rate of coal dust. The results showed that the wetting rate measured by Walket wetting rate experiment was mainly affected by the size composition of temperature coal dust, the concentration and molecular structure of the special surfactant used. In the temperature range of 10 40 C. The wetting rate increases linearly with the increase of temperature. Similarly, at a specific temperature, the wetting rate also shows a linear relationship with the increase of the average particle size of coal dust. To be careful
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2019-09-09 09:05:59
Surfactant adsorbs at the gas-liquid interface to form an adsorptive film. For example, a frictionless movable floating sheet is placed on the interface to push the adsorptive plasma membrane along the solution surface. The membrane produces pressure on the floating sheet. This pressure is called surface pressure. Surface Viscosity: Like surface pressure, surface viscosity is a property of insoluble molecular membranes.
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2019-09-06 09:03:38
Sealant is a kind of sealing material which is deformed with the shape of sealing surface and is not easy to flow. It is an adhesive used to fill the gap between configurations and act as a sealant. It has the functions of leak proof, waterproof, vibration proof, sound insulation and heat insulation. Usually asphalt, natural resin or synthetic resin, natural rubber or synthetic rubber and other dry or non-dry viscous substances are used as binders, with talcum powder, silica, titanium dioxide and asbestos inert fillers, followed by plasticizers, solvents, curing agents, accelerators and so on. It can be divided into three categories: elastic sealant, liquid sealing gasket and sealing putty. It is widely used in building, transportation, electronic instruments and parts sealing.
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2019-09-04 08:59:44
The main structure of polyurethane sealant is carbamate formed by the reaction of isocyanate and active hydrogen. It is characterized by good adhesion to various substrates, excellent toughness, good sealing performance, water and gas insulation. But the performance is poor at high temperature and humidity.
Silicone sealant has a structure of siloxane as the main chain, side chain or end group with functional groups, which plays a role in polymerization. Its characteristics are UV aging, thermal aging performance is very stable. But the bonding performance and sealing performance are poor.
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2019-09-02 00:00:00
In the guess of cable fire-proof coating, the technical path of taking part in aluminium hydroxide flame retardant is selected, so that when the developed cable fire-proof coating is obtained, the coating expands and foams well and densely, forming a fine and uniform fire-proof insulation layer, which can provide useful fire-proof maintenance for the cable. But when the content of aluminium hydroxide flame retardant is 7%, the cable fire retardant coating not only has good fire protection function, but also has outstanding physical and chemical function and clothing resistance function.
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2019-08-30 18:16:58
At present, chemical flooding is the main method of tertiary oil recovery in China. Surfactants are suitable for chemical flooding. On the basis of practical work experience, many experts and scholars have put forward the following requirements for surfactant in oilfields:
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2019-08-29 10:24:06
The main structure of polyurethane sealant is carbamate formed by the reaction of isocyanate and active hydrogen. It is characterized by good adhesion to various substrates, excellent toughness, good sealing performance, water and gas insulation. But the performance is poor at high temperature and humidity.
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