Carboxylic acid-containing polymers

Thiolated polymers, also termed thiomers, are conventional mucoadhesive polymers chemically modified to contain a cysteine residue in the polymer chain and thus establish covalent disulfide bonds with mucin." They can be manufactured to be either cationic (mostly thiolated chitosans) or anionic (carboxylic acid-containing polymers) however, their mucoadhesive extent will mostly be determined by their capacity to covalently bind to mucin. The polypeptide backbone of mucin can be divided into three major subunits tandem repeat array, carboxyl-, and amino-terminal domains. While the amino-terminal domain contains some of the cysteine residues, the carboxyl-terminal domain contains more than 10% of the cysteine residues. These cysteine-rich regions are responsible for forming the large mucin oligomers and ultimately, the groups that allow for the covalent mucoadhesive bond formation with oral mucosal systems." ... 

Figure 13.13 Synthesis of carboxylic acid-containing polymers via ADMET.

Polycarbodiimide methacrylates are obtained from the corresponding urea methacrylates. These polymers are utilized in the reaction with waterborne carboxylic acid containing acrylic polymers to produce waterborne polymers with methacrylic functonality." ... 

A 1 1 mixture of a carbodiimide containing latex polymer (t-butylcarbodiimidoethyl methylmethacrylate) and a carboxylic acid containing latex polymer (2-ethylhexyl methacrylate) showed that polymer interdiffusion occurs faster than crosslinking. Also, cyclohexylcarbodiimidoethyl methacrylate and t-butylcarbodiimidoethyl methacrylate have been prepared, and these monomers are used to prepare carbodiimide functionalized latex particles for emulsion polymerization. ... 

Hydrocarbon aerosol hair sprays contain an alcohol-hydrocarbon solvent-propellant system, a synthetic polymeric resin, a base to neutralize the resin if it is a carboxylic acid-containing resin, plasticizer(s), fragrance, and, in some cases, surfactant(s) to improve the spreading characteristics of the polymer. Most of the new low-VOC aerosol hairsprays contain alcohol-water as the solvent system and dimethyl ether as the propellant. Together the alcohol-dimethyl ether content must be below 55% (54.5%). For cost considerations, dimethyl ether is the propellant of choice, although Hydrofluorocarbon 152-A is exempt as a VOC and provides acceptable, but expensive formulations with previously used resins [54]. In Europe and other parts of the world, there are no VOC limits, and hydrocarbon-alcohol systems with virtually no water are widely used. 

Carboxylic acids contain the carboxyl functional group, often written COOH. ooo (Section 16.10) These weak acids are widely distributed in nature and are common in citrus fruits, ooo (Section 4.3) They are also important in the manufacture of polymers used to make fibers, films, and paints. T Figure 24.13 shows the formulas of several carboxylic acids. 

Barkac, K. A., et al. (2000). Thermosetting compositions containing carboxylic acid functional polymers and epoxy functional polymers prepared by atom transfer radical polymerization. In PCT Int. Appl. WO 0012583, Ppg Industries Ohio, Inc., USA, 72 pp. 

Divalent cations (ions such as magnesium, calcium and barium can result in precipitate formation of polymers containing carboxylic acid groups. Polymers containing sulphonic acid groups are much less susceptible to this problem). 

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