polyvinyl alcohol

Product description:

PVA (polyvinyl alcohol)

Chinese name: polyvinyl alcohol

English name: poly real (vinyl alcohol, viny) alcohol polymer, poval, hereinafter referred to as PVA

Molecular formula: [C2H4O] n

solubility

PVA soluble in water, the water temperature is higher, the greater the solubility, but hardly soluble in organic solvents. PVA solubility and polymerization degree and alcoholysis degree. Partial alcoholysis and low degree of polymerization PVA dissolved rapidly, while completely alcoholysis and high degree of polymerization PVA dissolved slowly. General rule, the influence on PVA solubility, alcoholysis degree is greater than the degree of polymerization. PVA dissolving process was conducted in stages, namely: affinity wetting dissolve a swelling, infinite swelling. Into membranous PVA film, the film of good mechanical properties, the tensile strength of the membrane with higher polymerization degree and alcoholysis degree increased. Adhesion of PVA with hydrophilic cellulose has good stick relay. Generally, the polymerization degree and alcoholysis degree is higher, the stronger the bonding strength.

Thermal stability

PVA powder is heated to 100 ℃, the appearance change gradually. Partial alcoholysis PVA melt to begin at about 190 ℃, 200 ℃ when a decomposition occurs. Completely alcoholysis PVA began to melt at about 230 ℃, 240 ℃ when the decomposition. Pyrolysis experiments show that the lower the degree of polymerization, the faster the weight reduction; The higher the alcoholysis degree, the shorter the time.

performance

rating

unit

The test method

Solution viscosity of 2

10 to 12

MPa s.

JIS K6726

PH 3

4.5 to 7.0

4 ash product

< 0.70%

volatiles

< 5.0%

Supplementary information

rating

unit

The test method

The Degree of Hydrolysis of 5

From 98 to 99%

Methanol can be extracted

< 3.0%