Product Properties
Polyvinyl alcohol (PVA) is a non-polluting water-soluble polymer, usually white or slight yellow floccule, flake, granular or powder solid. Its performance is between plastic and rubber. It has good adhesion, film-forming ability, insulation, oil resistance, abrasion resistance and gas barrier property, etc.
1).,Name:
Polyvinyl alcohol
Abbreviation: PVA
2),the molecular composition and structure:
( CH3CHCOOCH3 )x ( CH2CHOH )y
in which: x + y indicates the degree of polymerization, y / (x + y) that alcoholysis degree
3),The physical and chemical properties
The physical property
A,Solubility:
The Polyvinyl alcohol powder can be dissolved in water. PVA with Less than 95% alcoholysis degree can be dissolved in water at room temperature and PVA with more than 99.5% alcoholysis degree can only be dissolved in hot water above 95c.
B,Thermal Stability:
The heat can make PVA soften and there is no significant change below 40c but 160c or more, for a long time heated ,it will gradually be colored .when 220c above it is decomposed to produce water, acetic acid, a c etaldehyde and pr o pylene aldehyde.
C,Chemical Resistance:
PVA is almost free from weak acid, weak base, or the impact of organic solvents, oil is very high.
D,Storage Stability:
PVA is a low viscosity of the polymer, the solution is stable at room temperature. Aqueous solution in the storage process is not degenerate.
E,Film:
As the high adhesion between PVA molecular, PVA is easy to form a colorless, transparent film with good mechanical strength, smooth surface without tacky, and good solvent resistance. Monolayer has excellent light-admitting quality , high permeability rate, no charged, no absorption and good printing character .
The Chemical Property
PVA can be seen as a linear polymer with a hydroxyl polymer. Hydroxyl of molecules which has high activity can be a typical chemical reaction of low-alcohol, such as esterification, etherification, ac e tal, etc and can also react with a number of inorganic compounds or organic compounds.
Spec:
TESTED ITEM Unit PVA 2488 PVA 1799
Range of Insp Result Range of Insp. Result
Appearence -- -- White Flakes -- White Flakes
Alcoholysis Degree Mole(%) 87.0-89.0 88.5 99.0-100.0 99.6
Viscosity mPa.s 45.0-55.0 50.1 20.0-30.0 28.1
Volatile Wt(%) ≤5.0 2.5 ≤5.0 2.6
Ash % ≤0.5 0.28 ≤0.5 0.27
PH VALUE -- 5.0-7.0 5.8 5.0-7.0 5.6
TESTED ITEM Unit PVA 0588 PVA 2688
Range of Insp Result Range of Insp Result
Appearence -- -- White Flakes -- White Flakes
Alcoholysis Degree Mole(%) 87.0-89.0 88.6 87.0-89.0 88.1
Viscosity mPa.s 4.5-6.5 5 56.0-66.0 59.1
Volatile Wt(%) ≤5.0 2.6 ≤5.0 3
Ash % ≤0.5 0.3 ≤0.5 0.29
PH VALUE -- 5.0-7.0 5.9 5.0-7.0 5.9
TESTED ITEM Unit PVA 1788 PVA 088-20
Range of Insp Result Range of Insp. Result
Appearence -- -- White Flakes -- White Flakes
Alcoholysis Degree Mole(%) 87.0-89.0 88.5 87.0-89.0 88.6
Viscosity mPa.s 20.0-28.0 24.1 20.0-26.0 23.1
Volatile Wt(%) ≤5.0 2.5 ≤5.0 2.4
Ash % ≤0.5 0.28 ≤0.5 0.26
PH VALUE -- 5.0-7.0 5.8 5.0-7.0 5.3
Package, Transport and Storage:
Appearance:Floc , Flake, Powder.
A,12.5 kg, 20 kg, 25 kg plastic woven bag or paper bag, 750Kg ~ 1000Kg woven tons of bags.
B,Transport using a clean conveyance to prevent moisture, rain and sun and moving gently to prevent the package