Polyvinyl alcohol is an organic compound with the chemical formula [C2H4O] n. It appears as a white flake, flocculent, or powdery solid and is odorless. Soluble in water (above 95 ℃), slightly soluble in dimethyl sulfoxide, insoluble in gasoline, kerosene, vegetable oil, benzene, toluene, dichloroethane, carbon tetrachloride, acetone, ethyl acetate, methanol, ethylene glycol, etc. Polyvinyl alcohol is an important chemical raw material used in the manufacture of polyvinyl acetal, gasoline resistant pipes and vinylon, fabric treatment agents, emulsifiers, paper coatings, adhesives, glues, etc.

Density: The relative density of polyvinyl alcohol (25 ℃/4 ℃) is 1.27-1.31 (solid) and 1.02 (10% solution).

Glass transition temperature: 75-85 ℃.

Heating performance: Slowly change color and become brittle when heated to above 100 ℃ in air. Heating to 160-170 ℃ for dehydration and etherification, losing solubility, and starting to decompose at 200 ℃. Over 250 ℃, it becomes a polymer containing conjugated double bonds.

Refractive index: 1  49～1. 52.

Specific heat capacity: 1-5 kJ/(kg · K).

Ignition temperature (℃): 410 (powder)

Lower explosive limit% (V/V): 125 g/m3

Solubility: soluble in water, generally needs to be heated to 65-75 ℃ for complete dissolution. Insoluble in gasoline, kerosene, vegetable oil, benzene, toluene, dichloroethane, carbon tetrachloride, acetone, ethyl acetate, methanol, ethylene glycol, etc. Slightly soluble in dimethyl sulfoxide. Soluble in glycerol at 120-150 ℃, but becomes gelatinous when cooled to room temperature.