Carboxylation functionalized polymers

Physical crosslinking of carboxyl-functional polymers with multivalent ions... 

Polymer microbeads were also used for constructing an OP detection system using fluorescence response of the microbeads. Carboxylate-functionalized polymer microbeads that had been covered with a poly(vinylpyridine) (PVP) layer were modified with fluorescamine (FLA). When the microbeads were exposed to the vapor of diethyl... 

While UOi+ forms a very large number of complexes with oxygen-donor ligands of all types, particular effort has been devoted to carboxylic acids, from the simplest (formic, acetic, oxalic acids) to polyfunctional, aromatic and heterocyclic acids. One motive for investigating these compounds is the possible role of simple carboxylic acids as reductants [3, 5] of excited UVI, generating U,v which can then reduce Puiv to PuIn which is more readily separable than Pulv from UVI in the treatment of nuclear waste. Another significant role has been proposed for carboxyl-functionalized polymers which show potential in the solid-phase extraction of UV1 from dilute solution [13]. 

The polymeric complexes derived from 4-nitro- and cyanostilbazoles also show a smectic A phase up to about 200 °C [78a]. Polysiloxane complexes 32 also exhibit thermally stable smectic A or C mesophases [79-81]. These carboxyl-functionalized polymers and stilbazoles are miscible in a whole range of composition and show stable mesomorphic behavior [26, 79]. The introduction of the chiral stilbazole for the formation of a mesogenic complex leads to the induction of ferroelectricity [80]. Polymeric complex 33 exhibits a chiral smectic C phase, while no ferroelectricity is observed for each of single components. The value of spontaneous polarization for 33 x — 0.43, n = 5) is 21.0 nC/cm at 112 °C. The hydrogen bonding between the carboxylic acid and... 

Substituted DPEs have also been utilized to prepare carboxyl-functionalized polymers. The carboxyl functionality has been protected using the oxazoline group. The oxazoline-substituted DPE was not stable to the anionic chain end at room temperature, however. " It was necessary to effect this functionalization reaction in toIuene/THF mixtures (4/1, v/v) at -78 ° C to produce the carboxyl-functionalized polystyrene (Ain = 2.4 X 14.6 X lO gmoh ) in quantitative yield after acid hydrolysis as shown in eqn [42]. Quantitative formation of the oxazolyl-ftmctionalized polystyrene was determined by elemental analysis of the polymer. 

Summers, G. Anionic Synthesis of Aromatic Carboxyl Functionalized Polymers, The University of Akron Akron, OH, 1991. 

The ortho-ester functionalized polymers can be hydrolyzed to the corresponding carboxyl functionalized polymers. Similarly, fimctionalization with the oxiranes, glycidylpropyltrimethoxysilane, 3,4-epoxy-l-butene, and 1,1,1-trifluoro-2,3-epoxypropane has been investigated (195) to prepare trimethoxysilyl functionalized polymers, 1,3-diene fiinctionalized macromonomers, and trifluoromethyl functionalized polsrmers, respectively. Secondary amine functionalized polymers were prepared by termination with iV-(benzylidene)methylamine and also using an iV-benzyl tertiary amine functionalized alkyl lithimn initiator followed by hy-drogenolysis of the benzyl group. 

G. Caldwell and E. W. Neuse, Synthesis of water-soluble polyamidoamines for biomedical applications. 1. Carboxyl-functionalized polymers as potential-drug carriers. South Afr. J. Chem. -Suid-Afr. Tydskr. Chem., 45,93-102 (1992). 

The following sections describe the applications of substituted 1,1-diphenylethylene chemistry for the preparation of phenol, amino, and carboxyl functionalized polymers as well as for the preparation of polymers with aromatic functional groups which provide fluorescent labels. These examples show that anionic functionalization chemistry utilizing substituted 1,1-diphenylethy-lenes as outlined herein provides a versatile and general functionalization methodology for quantitative introduction of functional groups at the chain ends and within the polymer chain by design. 

The carboxyl group has also been protected using the diisopropylamide derivative [168]. It was found that the diisopropylamide group in 45 was not stable to the organolithium chain ends at room temperature [169]. Therefore, the functionalization reaction was effected in toluene/THF mixtures, (4/1, v/v) at -78 °C to produce the amide-functionalized polystyrenes in 92-100% yields as shown in Scheme 20. Although it was somewhat difficult to hydrolyze the amide, heating under reflux in toluene with toluenesulfonic acid was found to be effective in generating the carboxyl-functionalized polymers [169]. 

Multifunctional carbodiimides are designed for low temperature crosslinldng with carboxyl functional polymers as shown in Figure 7-17. 

Hexamethylolmelamine can further condense in the presence of an acid catalyst ether linkages can also form (see Urea Eormaldehyde ). A wide variety of resins can be obtained by careful selection of pH, reaction temperature, reactant ratio, amino monomer, and extent of condensation. Eiquid coating resins are prepared by reacting methanol or butanol with the initial methylolated products. These can be used to produce hard, solvent-resistant coatings by heating with a variety of hydroxy, carboxyl, and amide functional polymers to produce a cross-linked film. 

In addition to providing fully alkyl/aryl-substituted polyphosphasenes, the versatility of the process in Figure 2 has allowed the preparation of various functionalized polymers and copolymers. Thus the monomer (10) can be derivatized via deprotonation—substitution, when a P-methyl (or P—CH2—) group is present, to provide new phosphoranimines some of which, in turn, serve as precursors to new polymers (64). In the same vein, polymers containing a P—CH group, for example, poly(methylphenylphosphazene), can also be derivatized by deprotonation—substitution reactions without chain scission. This has produced a number of functionalized polymers (64,71—73), including water-soluble carboxylate salts (11), as well as graft copolymers with styrene (74) and with dimethylsiloxane (12) (75). 

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. 

Ebdon and coworkers22 "232 have reported telechelic synthesis by a process that involves copolymerizing butadiene or acetylene derivatives to form polymers with internal unsaturation. Ozonolysis of these polymers yields di-end functional polymers. The a,o>dicarboxy1ic acid telechelic was prepared from poly(S-s tot-B) (Scheme 7.19). Precautions were necessary to stop degradation of the PS chains during ozonolysis. 28 The presence of pendant carboxylic acid groups, formed by ozonolysis of 1,2-diene units, was not reported. 

We have developed an efficient and practical method for clean oxidation of starch (21-23) resulting in the oxidation of primary alcohol function in Ce position and the cleavage of vicinal diols in C2 and C3 position (Figure 30.2). We used small amounts of cheap iron tetrasulfophthalocyanine catalyst, pure water as reaction medium and H2O2 as clean oxidant to achieve a one-pot conversion of starch resulting in the introduction of aldehyde and carboxyl functions in polymer chains. The iron content... 

End-functional polymers were also synthesized by lipase-catalyzed polymerization of DDL in the presence of vinyl esters [103,104]. The vinyl ester acted as terminator ( terminator method ). In using vinyl methacrylate (12.5 mol % or 15 mol % based on DDL) and lipase PF as terminator and catalyst, respectively, the quantitative introduction of methacryloyl group at the polymer terminal was achieved to give the methacryl-type macromonomer (Fig. 12). By the addition of divinyl sebacate, the telechelic polyester having a carboxylic acid group at both ends was obtained. 

As an example, bulk modification by the organic reaction of unsaturated PHA with sodium permanganate resulted in the incorporation of dihydroxyl or carboxyl functional groups [106]. Due to the steric hindrance of the isotactic pendant chains, complete conversion could not be obtained. However, the solubility of the modified polymers was altered in such a way that they were now completely soluble in acetone/water and water/bicarbonate mixtures, respectively [106]. Solubility can play an important role in certain applications, for instance in hydrogels. Considering the biosynthetic pathways, the dihydroxyl or carboxyl functional groups are very difficult to incorporate by microbial synthesis and therefore organic chemistry actually has an added value to biochemistry. 

Fig. 1.14 (A) Single-wall carbon nanotubes wrapped by glyco-conjugate polymer with bioactive sugars. (B) Modification of carboxyl-functionalized single-walled carbon nanotubes with biocompatible, water-soluble phosphorylcholine and sugar-based polymers. (A) adapted from [195] with permission from Elsevier, and (B) from [35] reproduced by permission of Wiley-VCH.

Some of the most remarkable achievements include microencapsulation in polystyrenes such as entrapped 0s04 for olefin hydroxylation (exploiting the interaction between n-electrons of benzene rings of the polystyrenes used as polymer backbones and the vacant orbitals of the catalysts) 5 polyurea-entrapped palladium (PdEnCat)6 for a multiplicity of C C forming reactions and the use of carboxylic acid-functionalized polymer (FibreCat).7 In general, however, metal leaching cannot be avoided. The PdEnCat catalyst, for instance, leaches some 4% of palladium per catalytic reaction run. 

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. 

A new class of metal-loaded nanoparticles was developed by Reynolds et al. (95). These materials have a core-shell morphology, where the core is a functionalized polymer with a high affinity to the Gd(III) ions. The core polymer contained monomers with carboxylate pendant arms, such as ethylacrylate, methacrylate, butylacrylate or allylmethacrylate. The shell consisted of a... 

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

A functional polymer is a polymer that contains a functional group, such as a carboxyl or hydroxyl group. Functional polymers are of interest because the functional group has a desired property or can be used to attach some moiety with the desired property [Patil et al., 1998], For example, a medication such as chloroamphenicol, a broad-spectrum antibiotic,... 

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