Commonly Used Foam Agents and Foam Stabilizers are These

Mar 10, 2021

Commonly used foam agents and foam stabilizers are these
They make the pores fine and uniform. When the system is in the low viscosity stage, it stabilizes the pore wall/the pores can grow to a thickness suitable for the opening, creating conditions for the final opening. The type of foam is different, and the type of stabilizer used is also; at the same time, its main function is to nucleate and emulsify each component in the formula. The compatibility of the various components in the foam formulation is not good, so a stabilizer with a strong emulsifying ability is needed to emulsify and mix them uniformly. The soft foam is made of water as a blowing agent, which accounts for 3% to 5% of the weight of the polyether in the formula. The reaction rate of water and isocyanate is higher than that of isocyanate and polyol, so there are a lot of solids in the initial stage of foaming. Polyurea is formed, which is a defoaming agent that can help open and blast holes. Opening and popping are the stages when soft foam foaming must occur, otherwise, closed cells will appear, which will reduce the foam performance. However, the opening and popping must occur when the foaming reaction and the gel reaction are basically completed and reach equilibrium. That is, when the foam rises to the highest point and the strength of the foam can support its own weight, otherwise it will cause the foam to collapse. Therefore, another important function of the soft steam stabilizer is that it can dissolve the polyurea formed by the reaction in the early stage of foaming and can help open and burst holes in the late stage of foaming.

The foam stabilizer can reduce the surface tension of the polyurethane raw material mixture, and prevent the thermodynamically unstable state of the foam from appearing through the surface tension during the foam rise to maturation.
Surfactants containing sulfonic acid groups are good stabilizers for polyester foams, such as sulfonated ricinol sodium salt.

Water-soluble polyether siloxane is a stabilizer for polyether foam. It can be modified by molecular weight, functionality, and polyether copolymer to meet different production requirements, such as flat-top foamed block foam, olefin barrier Type polyether soft foam requires different foam stabilizers.
It can reduce the surface tension of the liquid phase and produce a large amount of uniform and stable foam. The admixture used to produce foamed concrete is called a foaming agent. The foaming agent used for mortar or concrete should have the following characteristics:
①Sufficient stability, so that the bubble film will not be destroyed when it is mixed with mortar or concrete;
②No adverse effect on the coagulation and hardening of cementitious materials.
The commonly used foaming agents are as follows.
①Rosin foaming agent
It is made from rosin (100~140g/m3), skin glue or bone glue (150~200g/m3), NaOH or KOH (18~24g/m3) and water.
②Waste animal hair foaming agent
It is made by dissolving waste animal hair in boiling NaOH solution, neutralizing and acidifying with sulfuric acid, filtering to obtain a red-brown liquid, then concentrating, drying and grinding.
③ Hydrolyzable blood foam agent
It is made from fresh animal blood, caustic soda, ferrous sulfate and gasified ammonium.
④Rosin soap foaming agent
Made from saponin-containing plants.
Blowing agent type 1. Anionic type: ① Sulfonate type: sodium cetyl sulfonate (AS); sodium secondary alkyl sulfonate (SAS); sodium dodecyl benzene sulfonate (ABS or LAS)
; Α-olefin sulfonate (AOS); fatty acid methyl ester α-sulfonate (MES); sodium alkylphenol polyoxyethylene ether sulfonate (Na-APESO); sodium alkyl alcohol polyoxyethylene ether sulfonate Salt (Na-AESO); Penetrant T; Detergent 209 (pancreas plus bleach T) (N-oleoyl-N-methyl taurate sodium)