Water soluble Azo polymerization initiators

Synazo's supplies Azo initiators for many polymerisation reactions. Our most important water soluble Azo Initiators are AZPH and AZIM, and are used in many application fields of polymerization of functionalized acrylic monomers.

AZPH (chemical name: 2,2'-Azobis-(Amidinopropane) Dihydrochloride) and AZIM (chemical name: 2,2'-Azobis(N,N'-dimethylene isobutyramidine) Dihydrochloride) are performance chemicals for several industrial application. They are water soluble polymerization initiator (class: azo initiator) with many versatile applications in polymer chemistry. They are widely used as source of free radicals and have several major advantages over other polymerisation initiators, e.g. peroxide initiators.

The most important characteristic of a polymerization initiator is the speed of formation of radicals. As a general measure, the terminus Half Life is used. The Half Life is defined as the time required for half of the molecules of a given quantity of initiator to decompose, and it is closely related to temperature as it follows kinetics under Arrhenius equation.

Applications in Industry

The most common industrial applications of 2,2'-Azobis(amidinopropane) Dihydrochloride are:

Final Application

Chemical Reactants

Product

Adhesives

Polyvinyl Alcohol

Adhesives

Consumer products/ Personal Care

Polyacrylic Acid and Copolymers

SAP (Superabsorbant Polymers) for Diapers, Feminine Hygiene Pads, Incontinence Pads, etc.

Consumer products/ Personal Care

Polyvinyl Methyl Ether/ Maleic Anhydride Copolymers

Hair Fixatives

Detergents

Polyacrylic Acid and Copolymers

Cobuilding agents (for Zeolithes)

Pharmaceuticals

Polyvinylpyrrolidone

Binders/Thickeners

Pharmaceuticals

Carboxypolymethylene

Controlled Release Tablets, Transdermal Additives

Pulp and Paper

Polyacrylamides, Polyamines, Polyquaternary Ammonium Compounds

Filler Retention Aids, Flocculants, Coagulants, Binders, Coatings, Paper Sizes, Drainage Aids, Dry Strength Additives, Rheology modifyers, Printing Aids

Textile

Polyacrylic acid and derivatives

Rheology modifyers, Polyacrylic acid and derivatives Priniting Aids

Textile

Fluorinated monomers

Repellents

Textile

Polyvinyl Alcohol

Warp Sizes

Water Treatment

Polyacrylamides, Polyamines, Polyquaternary Ammonium Compounds

Flocculants, Coagulants

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Advantages of 2,2'-Azobis(amidinopropane) Dihydrochloride

Among the major advanctages of Azo Initiator 2,2'-Azobis(amidinopropane) Dihydrochloride compared to other technologies are:

  • Higher stability (than peroxide initiators), affecting positively transport and storage of initiator;
  • Decomposition/production of radical source under first-order kinetics,
  • Not sensitive to metal salts, acids and bases;
  • Not sensitive to radical induced decomposition;
  • No production of additional radicals whith different and destructive properties such as Oxygen;
  • No deterioration of final product by Oxygen liberated (as when peroxide initiators are used);
  • Absence of autocatalytic decomposition as in the case of peroxide initiators which is very difficult to control;
    • In consequence, the benefits for the industrial application when using 2,2'-Azobis(amidinopropane) Dihydrochloride are:

  • Easy control of polymerization reaction;
  • Higher efficiency and predictability of reaction, compared to other sources of free radials (e. g. Peroxides);
  • Better control of and much higher definition of distribution of polymer chain length, creating a much higher uniqueness of end product;
  • No deterioration of final product because no Oxygen is liberated during reaction.

    • In contrast to other Azo initiators with neutral structure, 2,2'-Azobis-(amidinopropane) Dihydrochloride consists of protonated substructures at "normal" ph Values. Part of the decomposition kinetics may be explained by electrostatic repulsion between positively charged centers. As a basic environment may influence the protonation of the molecule, the half life behaviour is partly dependent on the pH.

    A possible disadvantage during use is based on the HCl salt form, namely the irritant (Xi) property of 2,2'-Azobis(amidinopropane) Dihydrochloride. In combination with the crystalline standard form of the product which may cause formation of dust, workforce protective measures have to be taken into account by the user.

    Chemiehandel Dr. Wolfgang Doerner has developed advanced forms of supply to overcome negative effects of dustiness of material at the point of use, and already is supplying this as well as other water soluble Azo Initiators in different supply systems:

  • crystalline, packed in standard PE bags,
  • granular, packed in standard PE bags,
  • crystalline, packed in big packs (20 kg and 25 kg),
  • packed in water soluble bags (5 kg).

    • The latter two delivery systems offer benefits such as substantial reduction of dust during filling operations.

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