Itaconic acid, polymerization

In the nonaqueous polymerization processes that are conducted in organic solvent or diluent, many of the carboxyl-containing monomers cited have successfully been used in the preparation of ASNE and HASNE ASTs. Reactivity ratios, rates of reaction, monomer-polymer solubilities, economics, and degree of polymerization were among the criteria considered in monomer selection. However, in the important aqueous processes of suspension and particularly emulsion polymerization, the water solubility and hydrophilicity of the carboxylic monomer was found to be of considerable importance. Fordyce and Ham (13) observed that a significant portion of itaconic acid polymerized in the aqueous phase when emulsion polymerization was carried out with styrene. Fordyce et al. (9, 10) reported that... 

White crystals m.p. 162-164 C. ll can be prepared by the fermentation of sugar with the mould Aspergillus lerreus or by healing citra-conic anhydride with water at ISO C. Electrolysis of the potassium salt in solution gives allene. Itaconic acid is used as a comonomer in plastics its esters are polymerized to lubricating oils and plasticizers. 

Itaconic acid, anhydride, and mono- and diesters undergo vinyl polymerization. Rates of polymerization and intrinsic viscosities of the resulting homopolymers ate lower than those of the related acrylates (see Acrylic ester polymers) (8,9). 

Itaconic acid is a specialty monomer that affords performance advantages to certain polymeric coatings (qv) (see Polyesters, unsaturated). Emulsion stabihty, flow properties of the formulated coating, and adhesion to substrates are improved by the acid. Acrylonitrile fibers with low levels of the acid comonomer exhibit improved dye receptivity which allows mote efficient dyeing to deeper shades (see Acrylonitrile polymers Fibers, acrylic) (10,11). Itaconic acid has also been incorporated in PAN precursors of carbon and graphite fibers (qv) and into ethylene ionomers (qv) (12). 

The bicontinuous-microemulsion polymerization technique has also been used to develop novel proton exchange membranes (PEM) for fuel cell evaluation [97]. A series of hydrocarbon-based membranes were prepared based on the formulation shown in Fig. 5, with additional ionic vinyl monomers such as VB-SLi or bis-3-sulfopropyl-itaconic acid ester. After polymerization, the membranes were treated with dilute H2SO4 (0.5 M) to convert them to PEM membranes. The good performance of these PEM membranes in a single fuel cell is illustrated in Fig. 9. 

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