News Details
Acrylic coating association type crosslinking thickener
2017-6-2 16:11:08
Acrylic coating association type crosslinking thickener
Contains no crosslinking agent DAP sample (N1) and w (DAP) for 0.1% of the sample (N2) with the increase of shear rate viscosity decreased, but the viscosity of N2 falling slowly, namely shear resistance than in N1. For w (DAP) for more than 0.5% of the sample (N3 and N4 interchange), due to its after alkali soluble viscosity is much smaller than N1 and N2, with the increase of shear rate viscosity is slightly lower, but the shear rate is greater than the basic constant after 5 r/min.
Obviously, in the type association thickener, formed by hydrophobic groups in hydrophobic associating fit in solution can form a three-dimensional network structure, the hydrophobic associating fit is equivalent to the reticular structure of polymer network knot, but if wrong chemical crosslinking polymer, this consists of linear polymer and its molecular chain hydrophobic groups formed by physical cross connected under high shear force are easy to be destroyed, the ability to resist shear thickening agent solution.
The effect of pH on the transmittance of the thickener solution. The preparation of the thickening agent was diluted to the solid content of 0.6 percent, and the NaOH solution of 1.0 mol l-1 was reduced by low to high tuned pH, and the transmittance of the emulsion was followed by the tracking test.
Quality is not higher than 0.5% of the sample for DAP of monomer (N1 and N2), when the pH value increased from 6.9 to 6.9, light transmittance rapidly rising, that can be observed in the experiments the emulsion milky-white rapid change to colorless transparent.
This is because the thickening agent of emulsion polymer contains a lot of methyl acrylic acid monomer units, when the pH value is less than 7, mainly exists in the form of carboxylic acid, with the addition of sodium hydroxide, with the increase of pH value, the pH value reached about 7 acid into acid sodium, a rapid increase in water soluble polymer from the thickener is a polymer solution, polymer particle increases quickly so that the system of light transmittance. After that, we continue to improve the pH, and the transmittance of the solution is basically constant.
Chinese name: Diethyl toluene diamine(DETDA)
Physical and chemical properties: light yellow transparent liquid, slightly soluble in water, soluble in alcohols, ethers, ketones and other polar organic solvents, and polyether, polyester polyol compatibility.
Density 1.022
Viscosity (20 ℃) ??mPa·ss290±10
Pour Point ℃-9
Boiling point of310°C
Flash Point°C161.1°C
When the pH is greater than 8, the transmittance of the thickener emulsion is in a platform area, and the change is small, indicating that the polymer is fully dissolved. DAP is a sample of 0.5 percent (N3) and 1.0 percent (N4), which is only about 10 percent or less after the pH is greater than 8.
In the experiment, the N3 and N4 samples were clearly observed, even though they were pale rather than transparent in high pH, indicating that the emulsion was not fully dissolved. With the increase of DAP in the monomer mass fraction, the thickening agent of polymer crosslinking degree increased, the alkali dissolved after the extension of molecular chain severely restrict, latex particles can only be limited swelling dissolves adequately, make the system of light transmittance decreased obviously.
The effect of pH on the viscosity of a thickening agent. The viscosity of the above samples was carried out by means of kinematic viscosimeter.
As the pH value increases, the non-dap sample N1 and DAP have low quality scores in the monomer, and the viscosity of the sample N2 increases abruptly after the pH value above 6.5, reaching the highest point in about 8.5. Contrast light transmittance, along with the change of pH value of thickener emulsion viscosity change is obviously due to swelling and dissolving process of latex particles of the sample, can also through the polymer carboxylic acid of neutralization, molecular chain in electrostatic repulsion and the extension of the resulting polymer molecular chain to understand.
For w (DAP) higher sample N3 and N4 interchange, crosslinking degree is higher, because the polymer micelle could not completely dissolved and only limited swelling, depends on the degree of swelling w (DAP). The viscosity of the base solution of the thickener on the DAP in the monomer is only slightly elevated by pH.
Shear properties of thickening agent solution. The above different w (DAP) thickener in the solid content of 0.6% and alkali solution pH = 8.3, under the condition of using rotary viscometer rotor (4 #), between 0.5 ~ 100 r/min change (r.) determination of viscosity, shear rate results as shown in figure 4. If the sample viscosity drop is not obvious when the shear rate increases, the test specimen is highly resistant to shear performance. On the other hand, if increasing the shear rate, the sample viscosity of the sample decreases rapidly, indicating that the specimen has poor shear performance.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
Contains no crosslinking agent DAP sample (N1) and w (DAP) for 0.1% of the sample (N2) with the increase of shear rate viscosity decreased, but the viscosity of N2 falling slowly, namely shear resistance than in N1. For w (DAP) for more than 0.5% of the sample (N3 and N4 interchange), due to its after alkali soluble viscosity is much smaller than N1 and N2, with the increase of shear rate viscosity is slightly lower, but the shear rate is greater than the basic constant after 5 r/min.
Obviously, in the type association thickener, formed by hydrophobic groups in hydrophobic associating fit in solution can form a three-dimensional network structure, the hydrophobic associating fit is equivalent to the reticular structure of polymer network knot, but if wrong chemical crosslinking polymer, this consists of linear polymer and its molecular chain hydrophobic groups formed by physical cross connected under high shear force are easy to be destroyed, the ability to resist shear thickening agent solution.
The effect of pH on the transmittance of the thickener solution. The preparation of the thickening agent was diluted to the solid content of 0.6 percent, and the NaOH solution of 1.0 mol l-1 was reduced by low to high tuned pH, and the transmittance of the emulsion was followed by the tracking test.
Quality is not higher than 0.5% of the sample for DAP of monomer (N1 and N2), when the pH value increased from 6.9 to 6.9, light transmittance rapidly rising, that can be observed in the experiments the emulsion milky-white rapid change to colorless transparent.
This is because the thickening agent of emulsion polymer contains a lot of methyl acrylic acid monomer units, when the pH value is less than 7, mainly exists in the form of carboxylic acid, with the addition of sodium hydroxide, with the increase of pH value, the pH value reached about 7 acid into acid sodium, a rapid increase in water soluble polymer from the thickener is a polymer solution, polymer particle increases quickly so that the system of light transmittance. After that, we continue to improve the pH, and the transmittance of the solution is basically constant.
Chinese name: Diethyl toluene diamine(DETDA)
Physical and chemical properties: light yellow transparent liquid, slightly soluble in water, soluble in alcohols, ethers, ketones and other polar organic solvents, and polyether, polyester polyol compatibility.
Density 1.022
Viscosity (20 ℃) ??mPa·ss290±10
Pour Point ℃-9
Boiling point of310°C
Flash Point°C161.1°C
When the pH is greater than 8, the transmittance of the thickener emulsion is in a platform area, and the change is small, indicating that the polymer is fully dissolved. DAP is a sample of 0.5 percent (N3) and 1.0 percent (N4), which is only about 10 percent or less after the pH is greater than 8.
In the experiment, the N3 and N4 samples were clearly observed, even though they were pale rather than transparent in high pH, indicating that the emulsion was not fully dissolved. With the increase of DAP in the monomer mass fraction, the thickening agent of polymer crosslinking degree increased, the alkali dissolved after the extension of molecular chain severely restrict, latex particles can only be limited swelling dissolves adequately, make the system of light transmittance decreased obviously.
The effect of pH on the viscosity of a thickening agent. The viscosity of the above samples was carried out by means of kinematic viscosimeter.
As the pH value increases, the non-dap sample N1 and DAP have low quality scores in the monomer, and the viscosity of the sample N2 increases abruptly after the pH value above 6.5, reaching the highest point in about 8.5. Contrast light transmittance, along with the change of pH value of thickener emulsion viscosity change is obviously due to swelling and dissolving process of latex particles of the sample, can also through the polymer carboxylic acid of neutralization, molecular chain in electrostatic repulsion and the extension of the resulting polymer molecular chain to understand.
For w (DAP) higher sample N3 and N4 interchange, crosslinking degree is higher, because the polymer micelle could not completely dissolved and only limited swelling, depends on the degree of swelling w (DAP). The viscosity of the base solution of the thickener on the DAP in the monomer is only slightly elevated by pH.
Shear properties of thickening agent solution. The above different w (DAP) thickener in the solid content of 0.6% and alkali solution pH = 8.3, under the condition of using rotary viscometer rotor (4 #), between 0.5 ~ 100 r/min change (r.) determination of viscosity, shear rate results as shown in figure 4. If the sample viscosity drop is not obvious when the shear rate increases, the test specimen is highly resistant to shear performance. On the other hand, if increasing the shear rate, the sample viscosity of the sample decreases rapidly, indicating that the specimen has poor shear performance.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
Spanish
French
Italian
Portuguese
Japanese
Korean
Arabic
Russian