4-Vinylpyridine styrene copolymer

Zhou L.L. and Eisenberg A., lonomeric blends. II. Compatibility and dynamic mechanical properties of sulfonated cis-l,4-polyisoprenes and styrene/4-vinylpyridine copolymer blends, J. Polym. Sci., Polym. Phy., 21, 595, 1983. 

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. 

With the purpose of increasing the range of available block copolymers, comonomers other than methacrylates and acrylates can also be involved in sequential polymerization, provided that they are susceptible to anionic polymerization. Dienes, styrene derivatives, vinylpyridines , oxiranes and cyclosiloxanes are examples of such comonomers. The order of the sequential addition is, however, of critical importance for the synthesis to be successful. Indeed, the pX a of the conjugated acid of the living chain-end of the first block must be at least equal to or even larger than that of the second monomer. Translated to a nucleophilicity scale, this pK effect results in the following order of reactivity dienes styrenes > vinylpyridines > methacrylates and acrylates > oxiranes > siloxanes. 

It has recently been found that chalcone formation may be carried out under the influence of copper(II) 2,2 -bipyridyl or a complex of cobalt(II) acetate and a 4-vinylpyridine-styrene-divinylbenzene copolymer, chalcone is obtained in high yield and the catalyst may be recovered and reused. ... 

The porogen is usually an inert solvent, or mixtures of inert solvent and polymers. The meso- and macropores in the polymer network are the voids once occupied by the porogen. Individual recipes for the preparation of macroporous polymer beads may seem complex in terms of the number of components involved and the required control of the experimental conditions. The technology, however, for their preparation has been developed to such a degree that excellent control over their properties (e.g. particle size, shape, porosity and chemistry) is routinely achieved. The vast majority of current macroporous polymers are based on styrene-divinylbenzene copolymers. Other suitable monomers include acrylates, methacrylates, hydroxyalkylacrylates, vinylpyridines and vinyl acetate. A wide range of products are available for HPLC in particle sizes from 5-20 p,m, pore diameters from about 2-400 nm, and surface areas from about 50-500 m /g [141,144,146-148]. 

The apparatus is described and details given of its use with PETP homopolymer, PS/poly(vinyl methyl ether) miscible blend and styrene-styrenesulphonic acid copolymer/ethyl acrylate-4-vinylpyridine copolymer ionomer blend with ionic interactions. Orientation and relaxation curves were obtained for all three samples. It is concluded that the technique is very efficient for obtaining curves with high precision. For these three systems, the relaxation rate increases with temperature. 

An investigation (113) of the Tg of the poly(styrene-co-vinylpyridine) copolymers quatemized with iodoalkane found that the Tg increased with increasing ion content, but that the increasing rate of the Tg with ion contents (dTg/dc) depended on the length of an alkyl chain. For example, dTg/dc for the ionomer quatemized with iodomethane was ca 3.2°C/mol%, while for the ionomer quatemized with iododecane it was only ca l.l°C/mol%. 

Vinylpyridines can be copolymerized radically with numerous common monomers. In many copolymerizations vinylpyridines are used in small quantities only. The most important technical product is a terpolymer from 1,3-butadiene (70 to 80% by weight), styrene (10 to 15%, and 10 to 15% of 2-vinylpyridine) [606]. Copolymers of methacrylic esters of long-chain alcohols and vinylpyridine have been applied as an oil additive. This and other applications for vinylpyridine copolymers are reviewed in detail in Ref. [607]. Copolymerization parameters are listed in Refs. [543,545,608,609] some of the newer results are given in Tables 5 and 6. 

Chen et al. [37] studied a series of complexes of styrene-4-vinylpyridine copolymers or poly(4-vinylpyridine) and transition metal chlorides. The transition metal-polymer complexes were used to prepare ultra-fine metallic particles dispersed in a polymer matrix by chemical reduction. Upon reduction, the metal ions were transformed into the corresponding nanometer scale metal particles with the protective polymers preventing the metal particles from oxidation and excessive aggregation. Ohtaki et al. reported the effects of polymer support on the substrate selectivity of covalently immobilized ultra-fine rhodium particles as a catalyst for olefin hydrogenation [38]. 

Methyl-5-vinylpyiidine-butadiene copolymers (usually about 20 80 molar) are now commercially available. These copolymers are compounded and vulcanized in much the same way as styrene-butadiene copolymers and the vulcanizates have broadly similar properties the vinylpyridine rubbers show improved low temperature flexibility, abrasion resistance and oil resistance. 

The same strategy has been used very recently to prepare BCs containing a low percentage of azobenzene moieties, from commercial poly(styrene)-h/oc/c-poly(4-vinylpyridine) copolymers. A chromophore with a carboxylic group has been used in the preparation of hquid crystalline BCs. It should be noted that these systems are only homogeneous when the percentage of... 

All three processes are very useful because of their efficiency and ease of use in a wide range of reaction types (bulk, solution, emulsion, and suspension) and their tolerance toward water and oxygen impurities. These are important advantages in industrial practice. Purification and separation are tedious and cosdy. ATRP and RAFT polymerization have been applied to the polymerization of a wide range of monomers (e.g., methaaylates, aaylates, styrenes, vinylpyridines, acrylonitrile, and acrylamides), while the range afforded by NMP has been more limited. NMP is best suited to styrenes and its copolymers, although new nitroxides have allowed the polymerization of methacrylates and acrylates. 

Vinyl pyridine-grafted polyolefins [229] having improved dyeability were prepared with >0.02 wt% based on the monomer of a perester catalyst and >0.1 wt% based on the monomer of a reducing agent promoter selected from lower-valent salts of multivalent metals, hydrosulfite, or alkali metal formaldehyde sulfoxylate. Thus, the polypropylene-styrene-vinylpyridine-graft copolymer prepared in the presence of 1 wt% sodium hydrosulfite and 0.5 wt% tert-huiyl 2-ethyl perhexanoate at 90 C was melt-spun into fibers... 

Methyl methacrylate/4-vinylpyridine copolymer styrene/4-vinylpyridine copolymer and 1,4-dioxane 77DJA... 

Star block copolymers in which each branch is an amphiphilic star block copol)nners can be obtained in a similar way. The polymerization of the second monomer can be initiated by the carbanions of the first one, that is, in the order of increasing electroaffinity. Typical examples include styrene/butyl methacrylate [75] and styrene/vinylpyridine [76]. 

Resin and Polymer Solvent. Dimethylacetamide is an exceUent solvent for synthetic and natural resins. It readily dissolves vinyl polymers, acrylates, ceUulose derivatives, styrene polymers, and linear polyesters. Because of its high polarity, DMAC has been found particularly useful as a solvent for polyacrylonitrile, its copolymers, and interpolymers. Copolymers containing at least 85% acrylonitrile dissolve ia DMAC to form solutions suitable for the production of films and yams (9). DMAC is reportedly an exceUent solvent for the copolymers of acrylonitrile and vinyl formate (10), vinylpyridine (11), or aUyl glycidyl ether (12). 

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