- Home >> Polyvinyl Alcohol(PVA) >> CHINA PVA Polyvinyl alcohol PVOH PVA-2088,2488
Introduction
Polyvinyl Alcohol (PVA) is a water soluble and biodegradable synthetic polymer. It is a dry solid, and is available
in granule and powdered forms. Grades include both fully hydrolyzed and partially hydrolyzed. PVA is an excellent
adhesive with superior bonding strength, film forming and emulsifying properties. The film of PVA exhibits outstanding
resistance to oil, grease and solvents. In addition to its film forming property, it has excellent adhesion to both hydrophilic
and hydrophobic materials. PVA has been extensively used in textile industry for warp sizing and resin finishing;
in paper industry for surface sizing and pigment coating; in the production of PVAc emulsion as protective colloid;
in the suspension polymerization of PVC as a dispersion agent; as binder for ceramics, magnet, foundry cores and pigments.
PVA is manufactured by polymerization of vinyl acetate monomer, by hydrolysis of the polyvinyl acetate.
HOPE WAY PVA is produced in a wide range of hydrolysis and polymerization. In the partially hydrolyzed grade,
86-89 mole% of acetate group is replaced by alcohol group. Likewise, in the fully hydrolyzed grade, 98.5~99.2
mole % of acetate group is replaced by alcohol group.
HWP-20: Partially hydrolyzed PVA with degree of polymerization about 2000.
higher degree of polymerization, so is the viscosity.
degree of hydrolysis is an expression of the ratio of hydrophilic alcohol group and hydrophobic acetate group.
The properties of PVA are summarized as follows.
Partially hydrolyzed grade PVA (HWP type) can be slowly dissolved in room temperature water.
But in normal uses, raising temperature to 90°C is necessary for saving dissolving time.
Super low hydrolyzed grade PVA (HWC type) can be dissolved in 25°C to 50°C water, according to their grades.Better water resistance film property than HWP type PVA film.
Dissolving rate is slower than HWP type PVA
