Hydro xyethylcellulose

Fig. 3.8 SEM micrographs of a gel synthesized by adding 10wt.% ofTHEOS to a 1.5wt.%. aqueous solution of cationic hydro-xyethylcellulose. The pictures were taken at various magnifications to demonstrate the main features of the material. (Unpublished results, Pictures taken by Dr. C. Abetz).

Moisture content commercially available grades of hydro-xyethylcellulose contain less than 5% w/w of water. However, as hydroxyethyl cellulose is hygtoscopic, the amount of water absorbed depends upon the initial moisture content and the relative humidity of the surrounding air. Typical equilibrium moisture values for Natrosol 250 at 25°C are 6% w/w at 50% relative humidity and 29% w/w at 84% relative humidity. 

Fillers (calcium carbonate, calcium sulfate, aluminum oxide, bentonites, wood flour) increase the solid content of the dispersion, and they are added up to 50%, based on PVAc. The purpose of their addition is the reduction of the penetration depth, a thixotropic behavior of the adhesive, gap filling properties, and the reduction of the adhesive costs. Disadvantages can be the increase of the white point and possibly the more marked tool wear rate due to greater hardness of the adhesive. Other components in PVAc formulations are defoamers, stabilizers, filler dispersants, preservatives, thickeners (hydro-xyethylcellulose, carboxymethylcellulose), poly(vinyl alcohols), starch, wetting agents, tackifiers, solvents (alcohols, ketones, esters), flame retardants, and others. 

Cellosize Hydro xyethylcellulose Union Carbide Corp. 

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