Polyvinyl Alcohol PVOH®725
LIWEI CHEMICAL CO. LTD
|
Appearance |
Slightly Yellow grains solid |
|
Total Solids wt%(min) |
98.0 |
|
Degree of Hydrolysis (mole %) |
72.5.0±1.0 |
|
Viscosity@20°C,4% solution (mPa.s) |
5.8±0.5 |
|
Ash Content (as Na2O) wt% (max) |
0.3 |
|
pH value |
4.5-7.0 |
| Packing |
In 25kg paper bag. |
|---|---|
| Storage | Powder 20°C 2 years; Floccule 20°C 2 years. |
| Shipping | Room temperature 5-30℃ in China; may vary elsewhere |
| Liwei PVA is one of the top 10 PVA factories and the top 100 strongest enterprises in anhui province.In 2005,Liwei PVA is evaluated as advanced and high technical company. We mainly deals in polyvinyl alcohol,PVA,PVA fiber and raw materials for producing PVA like vinyl acetate,calcium carbide. |
| For samples, pricing, or more information, please call us at 0086-25-52397803 or mai to info@china-pva.net or fill out the following form. We will respond to you as soon as possible. |
PVOH®725 is a 72.5 mole% hydrolyzed, polyvinyl alcohol which has been specially developed
for use as a primary suspending agent for vinyl chloride suspension polymerisation. Using
our exclusive batch process which in that it allows more efficient control over the degree
of hydrolysis and particle size of product.
PVOH®725 has lower molecular weight and lower viscosity in the grade. It was leading to
uniform PVC of good morphology over the entire K value range. Its high level of conjugated
carbonyl groupings in the polymer chain give it superior grain size efficiency.
Specifically, PVOH®725 is a suspending agent for suspension polymerisation of vinyl chloride monomer (VCM). The use of PVOH®725 requires no significant plant modification.
1.PVOH®725 should be stored away from wet areas and naked flames. Ingress of moisture should
be avoided to maintain product quality.
2.As supplied, the product should remain fit for use for 12 months from the date of
delivery. Beyond that date, the material may still be fit for use, but we would advise that
it is good practice to test the material. As such, we advise that material stored for 12
months or more after delivery should be tested before use.
3.Aqueous solutions of PVOH®725 if stored for long periods at elevated temperatures are
prone to mould and bacterial attack.
PVOH®725 has an influence on the PVC resin grain size distribution, porosity and bulk
density. This is due to the products surface active nature, reducing the interfacial tension
and enhancing distribution of initiator throughout the batch.
The principal advantages of using PVOH®725 can be summarized as follows.
1.The desired PVC grain size can be achieved using low levels of PVOH®725, over a wide range
of polymerisation temperatures, to produce high bulk density resins.
2.The PVC grains made with PVOH®725 tend to be more spherical such that higher bulk density
may be combined with minimum reduction in porosity and with optimum flow
characteristic.
3.The combination of PVOH®725 and PVOH®88 grades or secondary suspending agent grades give
PVC resins of narrow grain size distribution and a good balance of bulk density and
porosity.