Crosslinker selection

Cross-linking agent selection The cross-linking agent has a great influence on the water-absorbing properties of the water-absorbent resin. It directly affects the water absorption rate and the water-absorption rate of the water-absorbing agent. Since the core-shell type water-absorbing agent is formed by a stepwise polymerization, the resulting core and shell of the particles have different cross-linked structures.

Through experiments, it was found that the cross-linking agent A and the cross-linking agent B have a good cross-linking effect on the acrylic water-absorbent resin, in which the polymer produced under the cross-linking agent B is hard and has good permeability, so the cross-linking agent B is used as The cross-linking agent of the resin shell part is 013% of the acrylic monomer content of the shell part; the polymer produced under the action of the cross-linking agent A is soft, has a fast water absorption rate, and has a large water absorption rate, and can be used as a soft absorbent resin. In the core part, the core-shell type water-absorbent resin with a core-shell type water-absorbent resin has a low water absorption rate, a good permeability, and a high water absorption rate in the core part, so the reaction takes two stages. The choice of the amount of acrylic acid (core-shell ratio) is very important. If the amount of the shell part is too large, the overall water absorption of the resin is low; if the amount of the inner core part is too large, the resin will be soft and easily gelled into a bond. group. The effect of different core-shell ratios on the properties of the water-absorbing agent under the same conditions The core-shell ratio Physical properties of the product Water absorption (g/g) Hard, Slow and hard water absorption, Permeability Better Soft and flexible, Good permeability, Soft, Poor permeability, bonding into groups Through the experiment found that the core-shell ratio of 5B1 formed when the water-absorbing resin has the best overall water absorption performance.

Acrylic acid is used as the main raw material. In the reversed-phase suspension polymerization system, compound dispersants and two different cross-linking agents are used to carry out the polymerization in stages to synthesize a core-shell high internal cross-linked, externally cross-linked soft-core hard shell. Water-absorbent resins have good water absorption and permeability.