Carboxyl pendent groups

The simple polyarylesterketones, containing the carboxyl pendent groups [380] and flexible segments of oxyethylene [381] have been S3m-thesized either. 

The simple polyaiylesterketones, containing the carboxyl pendent groups... 

Finally, a new water-soluble polyphosphazene was recently synthesized that has the structure shown in 36 (46). This polymer has two attributes as a biomedical macromolecule. First, the pendent carboxylic acid groups are potential sites for condensation reactions with amines, alcohols, phenols, or other carboxylic acid units to generate amide, ester, or anhydride links to polypeptides or bioactive small molecules. Second, polymer forms ionic crosslinks when brought into contact with di- or trivalent cations such as Ca or Ai3+. The crosslinking process converts the water-soluble polymer to a hydrogel, a process that can be reversed when the system... 

In order to identify tyrosine derivatives that would lead to polymers that are processible, mechanically strong, and also biocompatible, we initiated a detailed investigation of the structure-property relationships in polyiminocarbonates and polycarbonates. Since the amino and carboxylic acid groups of tyrosine dipeptide (the N and C termini) provide convenient attachment points, selected pendent chains can be used to modify the overall properties of the polymers. This is an important structural feature of tyrosine dipcptide derived polymers. 

Acid-Catalyzed Chemistry. Acid-catalyzed reactions form the basis for essentially all chemically amplified resist systems for microlithography applications (61). These reactions can be generally classified as either cross-linking (photopolymerization) or deprotection reactions. The latter are used to unmask acidic functionality such as phenolic or pendent carboxylic acid groups, and thus lend themselves to positive tone resist applications. Acid-catalyzed polymer cross-linking and photopolymerization reactions, on the other hand, find application in negative tone resist systems. Representative examples of each type of chemistry are listed below. 

Functionalized PPV precursor polymers with ester and carboxyl side groups have been prepared." These polymeric tetrahydrothiophenium salts can be converted via the sulfonium route into PPVs. After conversion, the pendent carboxyl functionalities can be further exchanged by others, such as nitro, amino, and aldehyde functionalities. 

Rossignol, H., Boustta, M., Vert, 1999, Synthetic poly(P-hydroxyalkanoates) with carboxylic acid or primary amine pendent groups and their complexes. Intern. J. Biol. Macromol. 25 255-264... 

The viscosities of aqueous alginate solutions are influenced by pH due to the pendent carboxylic acid groups. Indeed, most of the anionic polysaccharides are affected to some degree by fluctuations in pH, particularly at the higher and lower extremes. The effect of... 

Initial polymerization studies were performed using monomer 53 containing the pendent carboxylic acid group with dinucleophiles 2d, 7, and lOd as shown in Scheme 17. The resulting polymers (56a-c) exhibited good solubility in polar aprotic solvents such as DMF and DMSO. These polymers were also soluble in aqueous solutions of sodium hydroxide. 

---