CAS 9003-01-4 9007-20-9 Carbomer 940 Powder carbopol 940 polymer thickener

Free sample high purity carbomer 940 powder thickener carbopol 940 powder CAS 9003-01-4 9007-20-9 54182-57-9

carbomer water deflated and crosslinking agent

carbomer water deflains mainly depends on the crosslink density of the polymer. If the crosslinking density is too high, the water molecules can cause the water molecules into the interior of the polymer particles, and the carbomer cannot be completely swelling, and uniformly disperse In the water, even the layering; if the crosslinking density is too low, although its water is swollen,

it reduces its gel strength, resulting in a decrease in thickening effect. In addition, the light transmittance of carbomer is also closely related to its water inflatability. Generally, the better the water deflains, the higher the light transmittance. For high low crosslinking density, it is generally measured by measuring the water absorption rate of cardoom. Generally, the higher the water absorption rate, the lower the crosslinking density.

1. Macroscopic manifestation of crosslinking dosage

As can be seen from Figure 1, as the amount of crosslinking agent is increased, the wetting time gradually increases, and the light transmittance is gradually decreased, and the water absorption is gradually decreased, and the dispersibility of carbomerin water decreases. This is mainly due to the increase in the amount of crosslinking agent, so that the crosslinking density of the polymer gradually increases, and the gel network becomes close. In particular, when the crosslinking agent is increased to 2.0%, the wetting time has increased significantly, and the light transmittance is greatly reduced, and the water absorption is significantly reduced, and it cannot be completely swollen in the water to produce a precipitate. This is due to the increase in the crosslinking density between the molecular chain, so that the movement of the motion of the polymer molecular chain is increased, and she is unable to be carried out in the action of water molecules, and a barrier is formed to block the water molecule diffuse into the intraceratures.

2. Microscopic performance of cross-linking dosage to carbomer water swelling property

In order to further evolve the above results, the sample first swells the sample in water, and then dried the sample solution, maintaining its microstructure in water, and then observed its microstructure by scanning the electron microscope, as shown in Figure 2.

It can be clearly visually seen by the SEM map. With the increase in the crosslinking agent, the crosslinking density of the carbomer polymer is gradually increased. When the crosslinking agent is 0.8%, only a network structure approximately one-dimensional network is formed, so it is easy to swell over the action of water molecules; when the amount of crosslinking agent increases to 1.2%, a body type gel is formed. Network, water molecules to spread to the intraceratures inside, it takes more time, but their gel network is still loose, so it has good swelling in water; when the crosslinking agent is increased to 2.0%, The increase in the association causes the polymer molecular chain to be too close to cause an interior of the polymer to form a film, which severely hinders the water molecules to diffuse into the intraceratures of the particles, resulting in the particles to fail, and finally form a precipitate.

As the crosslinking agent increases, the crosslinking density of the carbomer hydrogel has gradually increased. When the amount of crosslinking agent reaches 2. 0%, the carbomer hydrogel cannot be completely swollen in the water, producing a precipitate. Therefore, to make the carbomer have a shorter wetting time, a higher water absorption, the amount of crosslinking agent must be controlled, thereby controlling the crosslink density of the carbomer.