Solution polymerization itaconic acid

Returning to the polymerization of itaconic acid in an aqueous system, Tate [98, 99] indicates that 32% solution of itaconic acid in water with 2% of potassium persulfate (calculated on the monomer), upon reaction at 60 C for 47 hr, gave 93% conversion (by titration we presume this to be a double-bond determination for unreacted monomer). Partially neutralized itaconic acid (64% acid in water, diluted to 36% during the reaction, and 40% neutralized with sodium hydroxide) on polymerization in the presence of 1% of potassium persulfate (calculated on itaconic acid) at 60°C for 48 hr afforded only a 72% conversion (by titration). 

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. 

The methyl methacrylate-itaconic acid copolymer, P(MMA-co-ItaA), was prepared by slow free-radical solution polymerization in methanol under nitrogen using 2,2 -azobis-(2,4-dimethyl valeronitrile)(du Pont Vazo 52) as initiator. The molar ratio of monomer to initiator was in the range of 5xl03 to 10xl03. Reaction at 50°C for 30 to 40 hrs gave conversions of 10 to 30%. The reaction mixture was added to cold, deionized water and the precipitated polymer obtained was rinsed with 2-propanol. 

Courtaulds initially made a PAN fiber (RL Polymer) by a batch process, to be replaced by Courtelle, made by a continuous polymerization process. The author can remember the day when WG Schmidt found a suitable solvent for the RL acrylic polymer and went running round the laboratory holding a test tube aloft containing a solution of PAN in NaSCN. The process was developed and following two pilot plants at Coventry, a continuous production plant was built at Grimsby in 1959, based on a terpolymer, acrylonitrile/methyl acrylate/itaconic acid (AN/MA/ITA) system using NaSCN as a solvent [4]. An important parallel development was a plant to recover and purify the spent NaSCN, which was fed back into the system. 

ESR spectra of short-lived radicals in the liquid state. Applying it to the radical polymerization of AA, MAA, and itaconic acid (ITA), Fischer et al. <> -56) observed ESR spectra of monomer, dimer, and polymer radicals and discussed the conformations of these radicals in terms of the hyperfine splitting constants for their P-methylene protons. Ranby et al. 6i> extended its application to the radical polymerization of several monomers such as vinyl esters and butadiene and also to the copolymerization of binary monomer systems. However, the use of the thermal-redox radical-generating method has been chiefly restricted to reactions in aqueous solution. 

Similar polymerizations have been carried out at monomer concentrations of 0.2 M/liter using potassium persulfate as the initiator for the polymerization of methacrylic, acrylic, and itaconic acids at 50°C for 5 hr under reduced pressure. In this case, the solid acids were isolated by precipitation from the aqueous solution with ethyl acetate and reprecipitated from a methanol-ethyl acetate system [49]. 

The polymerization of itaconic acid seems not to have been studied very extensively, although industrial applications in copolymer systems appear to be of considerable interest. In view of the work of A. Katchalsky and coworkers [38] on the effect of pH on the polymerization of acrylic acid and methacrylic acid, analogous research on pH effects on itaconic acid reactions has been carried out to a limited extent [95, 96]. Typically, with a persulfate initiator in an aqueous solution at 50°C, the monomer is converted to an extent of 85-90% to its homopolymer within 35-45 hr. In the pH range of 2.3-3.8, the rate of polymerization is constant. As the pH increases, the rate becomes progressively slower and stops completely at a pH of 9. Generally, the last 5-10% of the monomer seems to be difficult to convert to polymer. 

Poly(itaconic acid) has also been prepared in a 0.2M/liter aqueous solution using potassium persulfate at 50 C over a 5-hr period under reduced pressure. After the polymer is reprecipitated twice into methanol-ethyl acetate, a polymer is isolated with a molecular weight of 1.64 x 10, determined by vapor pressure osmometry of a methanolic solution of the methyl ester prepared from the polymer [49]. Unfortunately Tsuchida and coworkers did not report on the quantitative extent to which poly(methyl itaconate) had been formed from this polymer (presumably by reaction with diazomethane). Consequently, there is little in the literature to confirm or dispute the paper by Braun and Azis el Sayed [97], which offered evidence that during the free-radical polymerization of itaconic acid, carbon dioxide evolves to a considerable extent. During the process, it seems that hydroxyl and formyl radicals are generated and incorporated in the macromolecule. It is proposed by these authors that the homopolymer of itaconic acid contains virtually no itaconic acid repeat units but rather intramolecular lactone rings and acetal- or hemiacetal-like moieties. Since the polymer remains soluble in the reaction solvent (dioxane). 

Polymerization of Itaconic Acid in Dioxane Solution in a Nitrogen Atmosphere [97]... 

Polymerization of monomers having high optical purity. The polymers belonging to this class are optically active, and many of them have been synthesized in order to use optical activity as a probe for the study of the conformational equilibria of polymer chains in solution. The investigations carried out by Walden (161) in 1896 on a polymer derived from the isoamyl ester of itaconic acid may be considered the very first approach of this kind. 

The polyacrylamide-chitosan (PAM-CS) hydrogels were synthesized in five different mass ratios (mAM/mcs 100/0, 95/5, 90/10, 85/15, 80/20). For this purpose, chitosan powder was dispersed in a 1.0 wt. % itaconic acid aqueous solution, in order to form a 1.0 wt. % chitosan solution. NMBA was added to an AM aqueous solution (mNMBA/MAM = 0.02). The solutions were mixed thoroughly and the polymerization took place at 50°C for 24 hr in presence of V-50 (my-so/niAM = 0.02). The total concentration of solids in the system was 6.0% with respect to the water. 

The most common poly(alkenoic acid) used in polyalkenoate, ionomer or polycarboxylate cements is poly(acrylic acid), PAA. In addition, copolymers of acrylic acid with other alkenoic acids - maleic and itaconic and 3-butene 1,2,3-tricarboxylic acid - may be employed (Crisp Wilson, 1974c, 1977 Crisp et al, 1980). These polyacids are prepared by free-radical polymerization in aqueous solution using ammonium persulphate as the initiator and propan-2-ol (isopropyl alcohol) as the chain transfer agent (Smith, 1969). The concentration of poly(alkenoic add) is kept below 25 % to avoid the danger of explosion. After polymerization the solution is concentrated to 40-50 % for use. 

---