Water soluble complex polymers belong to a family of products that, due to their applications, cannot be made up by a single chemical component (such as e.g. CMC, etherified starches, a vegetable gum or a resin), but different components are combined in order to afford a synergistic effect, which in turn is necessary for satisfying the requirements of a specific application, impossible to attain by other means.
The peculiar chemical properties of each individual components have been designed in order to afford the best possible combinations needed for yielding the desired results. By such means, complex although particularly effective products are obtained such as, for instance, in warp sizing, according to different types of yarns or in bulk paper-stock, for surface treatment, or in coatings, where the base polymers often need to be supplemented with different products, such as synthetic polymers, anti-foams, preservatives, retention-aids, vegetable gums, etc.
It is obvious that the complexity of products and the attainment of evermore complex properties by clients, has encouraged Barzaghi to update its own expertise and technical knowledge of products and their applications in order to offer to the market products aimed at satisfying the most exacting and diverse requirements.
Selected Advantages of our polymers
Cellulose and other naturally occurring polymers that we produce are used in several applications and, in general, whenever the following requirements are needed:
- To thicken an aqueous system
- Bind diverse blends of powders being used in extrusion or synterization
- To enhance particular adhesion requirements in paper, paper boards, and textiles
- To enhance the coating properties and plasticity of inert charges, such as plasters, fillings, chalks, concretes and pigments in general
- To impart surface slippery properties
- To adsorb oils and fats
- To favour water retention and delay the drying process
- To favour the suspension of charges in water systems
- To stabilize emulsions
- To form fils with excellent plastic properties
- To form clear and stable gels
POLYVINYL ALCOHOL (PVA)
Polyvinyl alcohol (PVA) is a perfectly soluble polymer in suitably heated water and insoluble in common organic solvents, a not possessed characteristic by most synthetic resins.
It appears as a granular powder, white or ivory and in aqueous solution, has a high film-forming power with a strong adhesion to the paper and many other types of supports. These characteristics depend on the degree of polymerization, this value leads to substantial viscosity differences in the solution.
Another factor that distinguishes the different types is the “degree of hydrolysis” caused by processing, more or less thrust, of polyvinyl acetate with polyvinyl alcohol which are ready.
This means that in the PVA molecules, next to alcohol groups may also be present unhydrolysed acetyl groups.
Polyvinyl alcohol is identified with two numerical values, the first number represents the average viscosity value at 20 ° C. of an aqueous solution at 4%, Brookfield viscometer, cPs expressed.
This value is directly proportional to the molecular weight, therefore, those with a greater viscosity will have a greater molecular weight.
The second number represents the average hydrolysis value of polyvinyl acetate.
Another important feature is its particular transparent film that offers no gas permeability.
Some examples of application:
- Textiles: as a primer and for natural fibers bonding, desizing with simple warm water.
- Glues and adhesives: rheology modifier and thickener, alternative to traditional glues, starch and Arabic Gum based, quick-drying glue.
- Paper industry: maximizes the optical brighteners effect, make special paper weatherproof to oils, grease, hydrocarbons and solvents.
Increase of mechanical resistance and flexibility, particularly at wet, dimensional stability and better paper printability.
- Emulsions and dispersions: for waxes, resins, metallic powders, etc.
The excellent colloid-protective and surface-active properties allow the preparation of emulsions and dispersions of various kinds, with high stability.
- Molds: in aqueous solution, is a great releaser.
- Agriculture: as a carrier and fixative for active ingredients.
- Filming: thanks to its ability to form resistant and elastic film, is used in many applications.
- Granulation: useful for granulate powders of various kinds.
- Inks: as color dispersing.
Barzaghi Srl Unipersonale Unipersonale was one of the first Italian companies to look with interest to this important polymer, so, we can now provide to our customers a wide range of polyvinyl alcohols in order to satisfy the most different requirements in many application.
Guar Gum is the name of an annual herbaceous plant (Cyamopsis tetragonolobus, Fam. Leguminosae) of Indian origin, but also grows in some others parts of the world, such as Pakistan, China and the United States.
No more than two meters high, this plant produces fruit (pods) containing 5-9 seeds from which the famous Guar Gum is derivated.
Once collected, these seeds are dried, peeled and then grounded.
The result of this production process is a water-soluble powder, white-ivory color and marketed under the name of Guar Gum or Guar Flour.
From the chemical point of view it’s a hydrocolloidal polysaccharide, composed primarily of galactomannans having high molecular weight; the latter are polymers constituted by linear chains of mannose monomers, branched monosaccharide units galactose.
The Guar Gum contains galactomannan in extent of 70-80%, a minimum amount of water (10-13%), proteins (4-5%), crude fiber (1.5-2%), fat (0, 50 to 0.75%) and traces of iron.
Some examples of application:
- Paper industry: preparation of the mass, before refining process, or in aqueous dispersion of headbox.
Guar Gum accelerates the mass hydration with a strong reduction of refining process with consequent energy saving, improvement in sheet formation, increase of mechanical strengths, this allows to increase machine speed, thanks to a better drying.
Better fillers retention while nonetheless preserving the strength properties, possibility to produce very resistant Kraft paper with wide porosity, two otherwise incompatible properties.
It can be used in surface treatments to control starch viscosity and dusting.
Recommended products: “Cartagel 3” range and “Gelogum / Carbofix G” range.
- Oil and geotechnical drilling: It’s used as a clay protective colloid, as a flocculant for water loss control.
Guar Gum is particularly suitable for drilling operation in presence of strong chlorides concentrations.
Operating in extreme conditions, the guar is able to form high-performing mud with minimal free water quantities and adjustable viscosity.
Recommended products: “Guarfix P” and “Ecomud P “
- Soil conditioning: improve soil structure and water loss control.
- Agrochemical: as thickened, suspending agent and film-forming.
The experience of Barzaghi company with this particular product has allowed, in 1975, to obtain a patent grant (n. ° 2543/75) which defined uses and properties of Glucoside-Guar copolymers in many sectors.
Currently, various Guar Gum formulations are available, in combination with cellulose ethers.
Xanthan gum is a complex carbohydrate, namely a high molecular weight polysaccharide, obtained by bacterial fermentation of a simple carbohydrate, such as glucose or sucrose.
To produce Xanthan Gum are used particular natural strains of “Xanthomonas campestris”, from which derives its name. The product obtained from this microbial fermentation is purified by extraction with ethanol or with 2-propanol, then dried and milled to obtain Xanthan Gum in the way of cream-colored powder, particularly water soluble, but insoluble in alcohol.
Its technical applications are varied, indeed is a great suspending agent, thickener and stabilizer.
Recommended product: Carbogum XK
Barzaghi company, in partnership with “Fufeng Group Limited” proposes on the Italian market, different degrees of Xanthan Gum, for several application field.