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| Thickening |
| Addition of an ALCOGUM® or ALCOGUM
L-SERIES rheology modifier to an aqueous system is noted by a significant
increase in the viscosity of the system. This response is typically
referred to as thickening the system. The degree of thickening
is a function of the thickener or rheology modifier selected,
the level used, and the shear rate at which the system is measured.
Arkem offers a broad range of thickeners and rheology modifiers
to assist in formulating products for application areas including
paper and paperboard coating, adhesive and textile compounding,
paint formulation, and cleaning compositions, among many others. |
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| Rheology Modification |
| Rheology is defined as the study of the deformation
and flow of matter. The deformation or flow is in response
to an external stress applied to a fluid system. The viscosity
of a fluid system is a measure of the fluid’s resistance
to flow. ALCOGUM® and ALCOGUM
L-SERIES rheology modifiers
enable the formulator to design optimized performance into
products in a broad range of application areas including paper
and paperboard coating, adhesive and textile compounding, paint
formulation, cleaning compositions among many others. |
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| Scale and deposit control |
Arkem’s line of AQUATREAT® polymers
provide control of mineral scale and deposits using a combination
of three mechanisms: Threshold Inhibition, Dispersion, and
Crystal Modification.
Threshold Inhibition defines the ability of the polymer to
maintain the solubility of an otherwise insoluble salt beyond
it’s normal or predicted limits at a sub-stoichiometric
level. This property allows Arkem’s AQUATREAT® products
to be powerful and cost effective tools in preventing precipitation
of various salts in a wide range of applications.
AQUATREAT® polymers are effective particulate dispersants. This
effect refers to the polymer’s ability to maintain a
stable distance between particles thus preventing agglomeration.
The end result can produce a suspension of particles in solution
or increase flowability of particles in systems where suspension
is not viable.
The crystal modification properties of polymers may be the
most powerful and most overlooked property of Arkem’s
AQUATREAT® products. These polymers have the unique ability
to modify forming inorganic crystals. Often, the severity of
the distortion will have a significant effect upon the properties
of the resultant crystal formation. An example of this effect
is in the control of calcium carbonate in industrial water
treatment systems. In these systems, calcium carbonate tends
to form in cubic structures called calcite. These calcite crystals
have large flats surfaces or faces which can tenaciously attach
to surfaces such as heat exchangers. This is a detrimental
effect as the buildup of these deposits will impede heat transfer
and plug the heat exchanger tubing. The addition of AQUATREAT® polymers can distort the forming calcite crystal such that
it’s ability to form a permanent attachment to a surface
is minimized and the surfaces are kept clean. |
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| Dispersant/Deflocculant |
Arkem polymers can provide both electrostatic
and steric stabilization of solid particulates in water, providing
a low viscosity suspension with good rheological properties.
Electrostatic stabilization comes from the coordination of
the polycarboxylates to the surface of the mineral particle.
The polymer is attracted to the surface by the particle positive
charge of the metal atom. For example, when dispersing calcium
carbonate, the anionic charge of the polymer is attracted to
the cationic charge of the calcium ion. The polymer is then
bound to the surface and, since it is overall negative in charge,
causes the particle to become more negatively charged. The
polymer then increases the negative surface potential (zeta
potential) of the particle. The more negative the zeta potential,
typically the more stable the dispersion as these negatively
charged particles repel each other and will not agglomerate.
Steric stabilization is accomplished when polymers attach to
the surface of particles but do not lie flat on the surface.
The polymers form loops and tails and increase the hydrodynamic
volume of the particle. This can prevent the particles from
getting close enough to coalesce and precipitate. |
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