GENERAL INFORMATION
PVOH 452 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 452 has high molecular weight and high viscosity in the
grade.
USES
Specifically, PVOH 452 is a suspending agent for suspension polymerisation of vinyl chloride
monomer (VCM).
STORAGE
1.PVOH 452 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 452 if stored for long periods at elevated temperatures are
prone
to mould and bacterial
attack.
FOR USED IN VCM SUSPENDING POLYMERISATION
PVOH 452 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 452 can be summarized as
follows.
1.The desired PVC grain size can be achieved using low levels of PVOH 452, over a wide range
of polymerisation
temperatures, to produce high bulk density resins.
2.The PVC grains made with PVOH 452 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 452 and PVOH HPMC-50 or secondary suspending agent grades give PVC
resins of narrow grain size
distribution and a good balance of bulk density and porosity.
