Putty powder is mainly composed of film-forming substances (bonding materials), fillers, water-retaining agents, thickeners, defoamers, etc. Common organic chemical raw materials in putty powder mainly include: cellulose, pregelatinized starch, starch ether, polyvinyl alcohol, dispersible latex powder, etc. Below, Polycat will analyze the performance and usage of various chemical raw materials for you one by one.

Fiber:

Fiber (US: Fiber; English: Fiber) refers to a substance composed of continuous or discontinuous filaments. Such as plant fiber, animal hair, silk fiber, synthetic fiber, etc.

Cellulose:

Cellulose is a macromolecular polysaccharide composed of glucose and is the main structural component of plant cell walls. At room temperature, cellulose is neither soluble in water nor in common organic solvents. The cellulose content of cotton is close to 100%, making it the purest natural source of cellulose. In general wood, cellulose accounts for 40-50%, and there are 10-30% hemicellulose and 20-30% lignin.

The difference between cellulose (right) and starch (left):

Generally speaking, both starch and cellulose are macromolecular polysaccharides, and the molecular formula can be expressed as (C6H10O5) n. The molecular weight of cellulose is larger than that of starch, and cellulose can be decomposed to produce starch. Cellulose is D-glucose and β-1,4 glycoside Macromolecular polysaccharides composed of bonds, while starch is formed by α-1,4 glycosidic bonds. Cellulose is generally not branched, but starch is branched by 1,6 glycosidic bonds. Cellulose is poorly soluble in water, while starch is soluble in hot water. Cellulose is insensitive to amylase and does not turn blue when exposed to iodine.

Cellulose Ether:

The English name of cellulose ether is cellulose ether, which is a polymer compound with ether structure made of cellulose. It is the product of the chemical reaction of cellulose (plant) with etherification agent. According to the chemical structure classification of the substituent after etherification, it can be divided into anionic, cationic and nonionic ethers. Depending on the etherification agent used, there are methyl cellulose, hydroxyethyl methyl cellulose, carboxymethyl cellulose, ethyl cellulose, benzyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, cyanoethyl cellulose, benzyl cyanoethyl cellulose, carboxymethyl hydroxyethyl cellulose and phenyl cellulose, etc. In the construction industry, cellulose ether is also called cellulose, which is an irregular name, and it is called cellulose (or ether) correctly.

Thickening Mechanism of Cellulose Ether Thickener:

Cellulose ether thickeners are non-ionic thickeners that thicken mainly by hydration and entanglement between molecules.

The polymer chain of cellulose ether is easy to form hydrogen bond with water in water, and the hydrogen bond makes it have high hydration and inter-molecular entanglement.

When the cellulose ether thickener is added to the latex paint, it absorbs a large amount of water, causing its own volume to expand greatly, reducing the free space for pigments, fillers and latex particles;

At the same time, the cellulose ether molecular chains are intertwined to form a three-dimensional network structure, and the pigments, fillers and latex particles are surrounded in the middle of the mesh and cannot flow freely.

Under these two effects, the viscosity of the system is improved! Achieved the thickening effect we needed!