Subject vinyl monomers

When these polymers are subjected to light of A = 365 nm in bulk vinyl monomer, (MMA or styrene) grafted or extensive crosslinking polymers were produced. The photografting or photocrosslinking occurs through the macro-radicals photochemically generated on the backbone of the polymer ... 

Cardanol grafted cellulose. One of the advanced techniques to improve the properties of a polymer is to graft another polymer onto it. Grafting of vinyl monomers onto cellulose has been the subject of extensive studies during the last decade or two. Grafted cellulose copolymers have been found to have improved proper-... 

The latter, used to investigate the cationic polymerization of vinyl monomers, is the subject of the presented article. The central point is not to collect all quantum chemical calculations carried out but to interprete some of this calculations in a reaction theoretical manner. 

Bfx, Fx, and related compoimds are the subject of a great munber of invention patents especially related to its uses in material sciences. For example, they were included in the formiflation as rubber additives [245,246], as inhibitors in the polymerization of aromatic vinyl monomers [247], as components in the igniting composition for inflation of airbags [248,249], as explosives [250-253], as soHd propellants [254], as burn-rate modifiers [255], and as liquid-crystalHne materials [256]. 

For most commercial resins, the diluent is styrene monomer, but it is possible to use other vinyl monomers such as methyl styrene and alkyl methacrylate monomers. These diluents serve two vital roles for the system. They reduce viscosity so the resins can be processed, and they cross-link with the double bonds in the polyester. The later, however, is the focus of this section. For more detailed reviews on this subject, readers are directed to the references listed at the end of this chapter [1-3]. 

Oster and Yang (1968) surveyed the subject of photopolymerization of vinyl monomers, and pointed out that one can use auramine O and similar... 

Poly (methyl methacrylate) was also subjected to mechanical reaction in a vibrating mill in common solvent for several monomers (ethylene, acrylic acid and its esters, acrylonitrile and styrene) at temperatures from —196 to 20° C (22). The formation of macroradicals and their reactions were followed by EPR (electron paramagnetic resonance). The macroradicals reacted with vinyl monomers at temperatures less than —100° C, while quinones underwent reaction as low as —196° C. The same experiments were performed also with polystyrene and polybutylenedimethacrylate. The radicals from polystyrene were more reactive than those from poly(methyl methacrylate). 

Reactivity ratios between acrylated lignin model compound (Fig. 2), defined as Mi, with either MM A or S, defined as M2, were determined experimentally in accordance with standard procedures (15). These involve mixing two different vinyl monomers in various molar ratios with catalyst (i.e., benzoyl peroxide) and solvent, heating the mixture to achieve polymerization, and recovering the polymer by the addition of non-solvent, and centrifugation. The respective molar monomer fractions of the copolymer were determined by UV-spectroscopy in the cases where MMA served as M2, and by methoxyl content analysis in those cases in which S was the M2-species. The results were subjected to numerical treatments according to the established relationships of Kelen-Tiidos (17) and Yezrielev-Brokhina-Roskin (YBR) (18), and this is described elsewhere (15). 

The various kinds of growing species differ not only in their propagation but also in their stereochemical preferences. Professor Hogen-Esch will review this subject in his talk on anionic oligomerization of some vinyl monomer, and mechanisms of anionic, stereospecific polymerization of 2-vinyl pyridine will be discussed by Dr. Fontanille. In this context, the interesting paper of Schuerch et al.(12) deserves attention. Their work clearly reveals the effect of cation solvation upon the mode of monomer s approach to the growing centers. 

Grafting vinyl monomers to flexible polyurethane foam is the subject of Skraba s chapter, and to wool is that of Stannett. 

Reaction medium. When lignosulfonate was subjected to graft copolymerization with vinyl monomers, the extent of copolymerization due to the effect of medium varied from one monomer to another. In a LS-styrene system (16), it was found that methanol was a better medium than water under certain given conditions while in a LS-acrylonitrile system (17),the contrary was true, i.e., water better than methanol. This contradiction was thought due to the fact that styrene has electropositive (i.e., electronreleasing) substituent while acrylonitrile has electronegative (i.e., electron-attracting) substituent. In the present study,... 

The subject of the kinetics of vinyl polymerization by radical mechanisms is treated exhaustively in a book by Bamford, et al. (4) and more briefly in many textbooks of polymer chemistry. The polymerization of vinyl monomers is a chain reaction in which the primary reactions are ... 

A variety of vinyl monomers, such as methyl methacrylate and styrene, may be used. Complete filling of the cell lumens and other voids (the full-cell process ) is easily accomplished by first subjecting the wood to a partial vacuum (about 0.3 in. of Hg) and then covering it with the monomer and soaking it for 2-6 hr, depending upon the species of wood and its dimensions. Some penetration of the monomer into the cell walls also may be obtained by using a diffusion process, such as a solvent-exchange method. 

Reactions of type (a) are among the most extensively studied, as they include the. synthesis of polyacrylamide Mannich bases, widely employed in water-purification processes. Many other polymeric substrates are, however, succe.ssfully subjected to Mannich reaction (Table 33). Moreover, some polymeric substances need to be suitably functionalized in order to undergo the aminomethylation reaction, as reported for polymeric ketones obtained by oxidation of polyenes." Further macromolecular carbonyl substrates could be provided by interesting vinyl monomers purposely designed to give polymers suitable for Mannich reaction." ... 

In the 1930 s, vinyl monomers were found to undergo chain polymerization when subjected to gamma-rays (6) or to neutrons generated by a cyclotron (7). However, the more extensive work was carried out in the late 1940 s when it became clear that powerful radiation sources would become practical tools of interest to industry. 

While free-radical chain reactions were known shortly after the turn of the 20th century, it was not until the mid-1930s that free-radical polymerization was recognized. Today, free-radical polymerization finds application in the synthesis of many important classes of polymers including those based upon methacrylates, styrene, chloroprene, acrylonitrile, ethylene, and the many copolymers of these vinyl monomers. Many good reviews and books on this subject are available.12... 

The subjects of reports on radiation-induced polymerization have included the following monomers ethylene,70 tetrafluoroethylene,71 acrylonitrile,72 acrylic acid,78 and methacrylonitrile,74 alkyl acrylates and methacrylates,76 styrene,78 other vinyl monomers,77 78 acrylamide,79 vinylcarbazole,80 maleimide,81 pentenes,82 aminoalkyl monomers,83 isobutyl vinyl ether,84 and buta-1,3-diene.85... 

Since the first preparation of stereoregular poly(methyl methacrylate) by Fox et al. and Miller et al. in 1958, a large number of papers have been published on the steieospecific polymerization of methyl methacrylate, while the NMR technique for the determination of microstructure developed by Bovey and Tiers and Nishioka et al. enabled us to accumulate the extensive information on this polymerization. Mostly anionic initiators have been used for the pdymerization. A review on the polymerization by lithium compounds was presented by Bywater In a recent review by Pino and Suter were discussed some of the factors which can influence the stereoregulation in the polymerization of vinyl monomers including a-substituted acrylate. A variety of magnesium and aluminum compounds can be utilized as stereospecific initiators. Besides methyl methacrylate, not only methacrylates with various ester groups, but also a-substituted acrylates, such as a-ethyl- or o-phenyl-acrylate, were also subjected to the stereospecific polymerization by anionic initiator. The stereospecificity in the copolymerization between the monomers described above is also a matter of interest. 

The aim within the frame of this book is not to survey the plethora of pubH-cations devoted to surface photografting. Typical work pubhshed in recent years is compiled in Table 11.6, which demonstrates that the enhancement of hydro-philicity and wettabiUty of hydrophobic polymers and the improvement of adhesion of polymers to various substrates are still major research topics (see also [99]). Moreover, the grafting of ultrafine inorganic particles, such as nanosized silica and titania, with vinyl monomers is an attractive subject. Relevant earHer work on surface photografting has been reviewed by Yagci and Schnabel [84]. 

In vinyl monomers both olefmic carbons are potentially subject to free-radical attack. Each would give rise to a different terminal unit ... 

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