Vinylpyridines, copolymerization with

Catalysts of the Ziegler type have been used widely in the anionic polymerization of 1-olefins, diolefins, and a few polar monomers which can proceed by an anionic mechanism. Polar monomers normally deactivate the system and cannot be copolymerized with olefins. However, it has been found that the living chains from an anionic polymerization can be converted to free radicals in the presence of peroxides to form block polymers with vinyl and acrylic monomers. Vinylpyridines, acrylic esters, acrylonitrile, and styrene are converted to block polymers in good yield. Binary and ternary mixtures of 4-vinylpyridine, acrylonitrile, and styrene, are particularly effective. Peroxides are effective at temperatures well below those normally required for free radical polymerizations. A tentative mechanism for the reaction is given. 

Vinyl- and 4-vinylpyridines and 4-dimethylaminostyrene copolymerize with 2,4,6-trinitrostyrene without added initiator. The authors conclude that zwitterion formation is the first step. These copolymerizations seem to be analogous to those recently investigated by Saegusa and to be described later. 

The poly(vinylpyridine) chloride was then copolymerized with NIPAM in the presence of N,N -mclhylcncbisacrylamide to obtain graft copolymer gels. These gels were found to be temperature- and pH-dependent. But above 33 °C, the authors showed aggregation of the poly(NIPAM) phase and a pH > 5.5 leads to aggregation of the poly(vinylpyridine). However, the pH effect remains minor compared with that of temperature. 

The ability of such monomers as 4-vinylpyridine (VPy), acrylonitrile (AN) and methylmethacrylate (MMA) to coordinate can be used in the anionic-coordination copolymerization with ethylene using a catalytic system of MX -L -A1(C2H5)2C1. The complexes of transition metal halides such as V(AN) CU, V(VPy)2Cl4, V(MMA)Cl4, Ti(VPy)2Cl4 (n = 2, 3) are both comonomers and catalytic components [117,118]). 

Vinylpyridine is copolymerized with the Ru(II) complex of 4-vinyl-4 -methyl-2,2 -bipyridine by a radical mechanism to polymers 103 (Eq. 4-39) [119]. 

With this method, template monomers for dioxin [23] and a tripeptide [24] have been synthesized (Fig. 19). The template monomer 31 and 32 were both copolymerized with DVB. In the case of the tripeptide, vinylpyridine was added to form non-covalent interactions with the carboxylic acid groups of the peptide. The imprinted polymers bound the target molecule better than the control polymers in both cases. 

Alpha-picoline (2-picoline 2-methylpryridine) is used for the production of 2-vinylpyridine, which, when copolymerized with butadiene and styrene, produces a product that can be used as a latex adhesive which is used in the manufacture of car tires. Other uses are in the preparation of 2-beta-methoxyethyl-pyridine (known as promintic, an anthelmintic for cattle) and in the synthesis of a 2-picoline quaternary compound (amprolium), which is used against coccidiosis in young poultry. Beta-picoline (3-picoline 3-methylpryridine) can be oxidized to nicotinic acid, which, with the amide form (nicotinamide), belongs to the vitamin B complex both products are widely used to fortify human and animal diets. Gama-picoline (4-picoline 4-methylpyridine) is an intermediate in the manufecture of isonicotinic acid hydra-zide (isoniazide), which is a tuberculostatic drug. 2,6-Lutidine (2,6-dimethylpyridine) can be converted to dipicolinic add, which is used as a stabilizer for hydrogen peroxide and peracetic acid. 

A few spontaneous copolymerizations between exceptionally reactive donor acceptor olefinic pairs have been observed. Miller and Gilbert [37] observed that vinylidene cyanide spontaneously copolymerized with vinyl ethers when the two monomers were mixed at room temperature. Yang and Gaoni [38] observed that 2,4,6-trinitrostyrene as the acceptor monomer spontaneously copolymerized with 4-vinylpyridine as the donor monomer when the two were mixed at room temperature. Butler and Sharpe [39] reported that divinyl ether and divinyl sulfone spontaneously copolymerized upon monomer mixing. Thus, the participation of the charge-transfer complex in the copolymerization mechanism of such strong electron donor electron acceptor monomer pairs appears to have considerable support. 

On the other hand, cationic polymer brushes grafted on PET surfaces could prevent microbial infection in industrial and medical fields, such as alkyl pyridinium or quaternary ammonium moieties. Gen et al. grafted copolymerized with 4-vinylpyridine (4VP) and subsequently quaternized with hexylbromide [53,54], and N-hexyl-N -(4-vinylbenzyl)-4,4 -bipyridinium bromide chloride (HVV) [55] onto PET films for enhancing antibacterial properties. The PET films were pretreated by argon plasma to form surface... 

Heavy-duty (HD) additives keep solid combustion and oxidation products in suspension, thus avoiding deposits on metal surfaces, sludge formation and corrosive wear by neutralizing acidic decomposition products. Detergents, some of them RR-based, have sulfonate, hydroxy and/or carboxyl groups and usually contain metal ions or amine functions. More modem HD additives are based on methacrylates of fatty alcohols (Cn-ig), copolymerized with diethylaminoethyl methacrylate (9 1), vinylpyrollidone, N-vinylpyridine and hy-droxyethyl methacrylate. These ash-free dispersants may act also as VI improvers. Extreme-pressure (EP) additives ... 

Copolymerization can be carried out with styrene, acetonitrile, vinyl chloride, methyl acrylate, vinylpyridines, 2-vinylfurans, and so forth. The addition of 2-substituted thiazoles to different dienes or mixtures of dienes with other vinyl compounds often increases the rate of polymeriza tion and improves the tensile strength and the rate of cure of the final polymers. This allows vulcanization at lower temperature, or with reduced amounts of accelerators and vulcanizing agents. 

AlkyUithium compounds are primarily used as initiators for polymerizations of styrenes and dienes (52). These initiators are too reactive for alkyl methacrylates and vinylpyridines. / -ButyUithium [109-72-8] is used commercially to initiate anionic homopolymerization and copolymerization of butadiene, isoprene, and styrene with linear and branched stmctures. Because of the high degree of association (hexameric), -butyIUthium-initiated polymerizations are often effected at elevated temperatures (>50° C) to increase the rate of initiation relative to propagation and thus to obtain polymers with narrower molecular weight distributions (53). Hydrocarbon solutions of this initiator are quite stable at room temperature for extended periods of time the rate of decomposition per month is 0.06% at 20°C (39). 

In contrast to /3-PCPY, ICPY did not initiate copolymerization of MMA with styrene [39] and AN with styrene [40]. However, it accelerated radical polymerization by increasing the rate of initiation in the former case and decreasing the rate of termination in the latter case. The studies on photocopolymerization of MMA with styrene in the presence of ICPY has also been reported [41], /8-PCPY also initiated radical copolymerization of 4-vinylpyridine with methyl methacrylate [42]. However, the ylide retarded the polymerization of N-vinylpyrrolidone, initiated by AIBN at 60°C in benzene [44]. (See also Table 2.)... 

Kureshy developed a polymer-based chiral Mn-salen complex (Figure 21). Copolymerization of styrene, divinylbenzene, and 4-vinylpyridine generated highly cross-linked (50%) porous beads loaded with pyridine ligands at 3.8 mmol g-1. Once the polymer was charged with the metal complex catalyst, enantioselective epoxidation of styrene derivatives was achieved with ee values in the range 16 46%. 79... 

Copolymers of styrene with 4-vinylpyridine (II) and N-viny1imizado1e (III) were obtained by copolymerization for one day at 60°C in 25 wt% comonomer solutions in toluene, using AIBN as initiator. In all cases the degrees of substitution, a, of the functionalized polymers with ligand groups were derived from the nitrogen contents found by elemental analyses. 

Donor-acceptor interaction between monomer and polymer template offers an elegant methods of replication degree of polymerization. Similar system was described for copolymerization of vinylpyridine with p-chlorostyrene in the presence of poly(maleic anhydride) used as template. " ... 

It was found that a mixture of 4-vinylpyridine with p-chlorostyrene copolymerizes without any initiator in the presence of poly(maleic anhydride) at 50°C in DMF. The fact that poly(maleic anhydride) cannot initiate the polymerization of styrene or phenyl vinyl ether shows that poly(maleic anhydride) does not act as a normal anionic or cationic initiator. The compositions of copolymers obtained with various initial compositions of... 

Under copolymerization, the preferred sorption of one of the monomers on the matrix leads to enriching the daughter chains with this monomer. For instance, Polovinsky showed that MA — methyl methacrylate 85) and MA-styrene 86) copolymers, formed in the presence of a PEO matrix, are enriched in MA, the constants of copolymerization depending on the concentration of the matrix. It is shown by Kargina et al. 87) that in the presence of a PPh-Na matrix copolymers of 2-methyl-5-vinylpyridine and AA are considerably enriched in the cation monomer up to complete elimination of AA and formation of homopoly-2-methyl-5-vinylpyridine. 

Acrylonitrile based membranes were also used in acetic acid-water separation. Lee and Oh [11] copolymerized 4-vinylpyridine with acrylonitrile in order to prepare a membrane for the dehydration of water-acetic acid mixture by pervaporation. Yoshikava et al. [25] reported that membranes prepared from poly (acrylic acid-co-acrylonitrile)... 

In the present paper we pay special attention to block polymers with polypropylene and polyethylene as the initial anionic block. However, both crystalline and amorphous block polymers of ethylene and propylene, butadiene, and several other olefins and dienes have been made by the AFR technique. The second or free radical block has been made from 4-vinylpyridine, 2-methyl-5-vinylpyridine, and mixtures with other monomers, as well as a number of acrylic monomers. Vinyl chloride, vinylidine chloride, vinyl acetate, and several related monomers have not been successfully copolymerized. 

The various data obtained for the kinetics of graft copolymerization onto PTFE films demonstrate that this reaction is complicated by the fact that the rate of diffusion of the monomer may become the controlling factor. It seems interesting at this point to compare and discuss together the results obtained with the different monomers. Table I summarizes the data obtained for autoacceleration indexes (/ ), dose-rate exponents (a), and over-all activation energies E, with styrene, acrylic acid, and vinylpyridine. Several conclusions can be derived from an examination of these data. 

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