Polymer carboxyl-containing

Copolymers wet and adhere well to nonporous surfaces, such as plastics and metals. They form soft, flexible films, in contrast to the tough, horny films formed by homopolymers, and are more water-resistant. As the ratio of comonomer to vinyl acetate increases, the variety of plastics to which the copolymer adheres also increases. Comonomers containing functional groups often adhere to specific surfaces for example, carboxyl containing polymers adhere well to metals. 

The interaction of the polymer with the filler is promoted by the presence of reactive functionality in the polymer, capable of chemical reaction or hydrogen bonding with the functionality, generally hydroxyl, on the surface of the filler. Thus, carboxyl-containing polymers, e.g. ethylene-acrylic acid copolymers and maleic anhydride- and acrylic acid-grafted polyethylene and polypropylene interact readily with fillers. 

Low-molecular-weight carboxyl-containing polymers have been used to control the deposition of calcium phosphate (2-8). These polymers also function as... 

FIGURE 11.5 Degradation of N-a-benzoyl-l-arginine ethyl ester by trypsin. All three carboxyl containing polymers have antitrypsin activity, but the activity of trypsin in the presence poly(ethylene glycol) modified poly(methacrylic acid) is not greatly reduced. (Adapted from Madsen and Peppas 1999.)... 

Reactive polymer processing has been used extensively in the manufacture of carboxyl-containing polymers (8). The carboxylation of unsaturated polymers with maleic anhydride (MAH) proceeds through the ene reaction where succinic anhydride is attached to the polymer with a shift of the double bond to the adjacent site. 

N. G. Gaylord, Reactive Extrusion in the Preparation of Carboxyl - containing Polymers and their Utilization as Compatibilizers, in Reactive Extrusion, M. Xanthos, Ed., Hanser, New... 

IM-COOH-OH cooperation. Polymers such as poly(4(5)-vinylimidazole-co-7-vinyl-7-butyrolactone), poly(IM-la), and poly(4(5)-vinylimidazole-co-acrylic acid-covinyl alcohol) derived from poly(4(5)-vinylimidazole-co-methyl acrylate-co-vinyl acetate), both of which contain imidazole, carboxylic acid and hydroxyl moieties are synthesized and studied as a model of a-chymotrypsin (29). The former has a relatively ordered sequence and the latter has a random one. Results are tabulated in Table 11. The polymers cited in the Tabel contain a similarly low quantity of imidazole moiety, so that the cooperation of two subsequent imidazole moieties need not be discussed. Polymers such as L-84, L-68, M-83 and A-84 have higher catalytic activities than the polymer V-82. This suggests that the catalytic activity of the imidazole moiety in the polymers is much promoted by the carboxylate moiety in the polymers. The catalytic activities of L-84 and L-68 which have an ordered sequence are more than twice as high as that of M-83, having a random sequence. From these results it is concluded that the introduction of the hydroxyl moiety which has little cooperative effect on the imidazole moiety in V-82 in this reaction conrfition into imidazole and carboxylate — containing polymer, increases... 

A review (13) of water-based inks points out that ink vehicles must have "tack" for printability and that high solution viscosities are requited to give this tack. The viscosity of most latexes is too low to give this tack, so water-soluble or water-solubilized polymers are usually used. Upon drying, however, these polymers must no longer be soluble in water. Therefore, most water-based ink vehicles are ammonium hydroxide-neutralized alkaline solutions of carboxyl-containing polymers when the solution is dried, the ammonia evaporates, leaving the polymer in its water-insoluble carboxyl form. 

Unfortunately, values of yd and yp for mucus and glycoproteins, the main components of the mucous layer, are not yet available, but from the fact that the best candidates for bioadhesion are hydroxyl- and carboxyl-containing polymers, one can infer that the polar component is the predominant factor. The experimental data relating cellulose derivatives (mostly by measuring bioadhesive force) generally only compare NaCMC to one or two nonionic derivatives and the former always proved to be superior to the latter, and equivalent to other carboxyl-containing polymers (see e.g. [85]). 

Reaction 17 shows that carboxylate containing polymers have been used to initiate graft polymerizations of anionically polymerizable monomers such as lactones (54). 

NG Gaylord. Reactive extrusion in the preparation of carboxyl-containing polymers... 

Several surface modification methods for synthetic polymers have been described, for example, the use of chemical finishers based on carboxyl-containing polymers [100]. Alkaline and acid hydrolysis treatments are unspecific and result in strength and weight losses [97, 108]. Ionized gas treatment of PET materials using plasma has also been investigated to introduce hydrophilic groups at the surface of the polymer [80]. However, the application of this method is limited because it is complicated to use, and it can be difficult to control the extent of the material modification [16]. 

The use of carboxyl-containing polymers, e.g. ethylene-acrylic acid copolymers, in lieu of MAH-peroxide-high melt index LDPE, in the preparation of the masterbatch, failed to increase the impact strength, presiamably due to the absence of crosslinking and the graded modulus. 

Chemical modification may result in carboxyl-containing polymers that are usefiil as compatibilizing agents in the preparation of blends with, e.g., polyamides. 

Luo, X.F., Goh, S.H., and Lee, S.Y. (1999) Miscibility and interpolymer complexation of poly(l-vinylimidazole) with hydroxyl-and carboxyl-containing polymers. Macromol. Chem. Phys., 200, 399-404. 

Erickson and Krajewski [44] prepared absorbent polyacrylates by reacting a carboxylate containing polymer with a crosslinker which can react with carboxyl groups. The reaction was conducted in a viscous, aqueous solution which had been aerated such that the resulting cured film had rapid absorbence of aqueous fluids due to increased porosity. The pre-cure solutions could also be coated onto various substrates, cured and dried to give absorbent structures. 

---