Acrylamide polymerization with quaternary

The Polymerization of Quaternary Ammonium Cationic Monomers with Acrylamide... 

Kurokawa et al. [258-260] developed a novel but somewhat complex procedure for the preparation of PP/clay nanocomposites and studied some factors controlling mechanical properties of PP/clay mineral nanocomposites. This method consisted of the following three steps (1) a small amount of polymerizing polar monomer, diacetone acrylamide, was intercalated between clay mineral [hydrophobic hectorite (HC) and hydrophobic MMT clay] layers, surface of which was ion exchanged with quaternary ammonium cations, and then polymerized to expand the interlayer distance (2) polar maleic acid-grafted PP (m-PP), in addition was intercalated into the interlayer space to make a composite (master batch, MB) (3) the prepared MB was finally mixed with a conventional PP by melt twin-screw extrusion at 180°C and at a mixing rate of 160 rpm to prepare nanocomposite. Authors observed that the properties of the nanocomposite strongly dependent on the stiffness of clay mineral layer. Similar improvement of mechanical properties of the PP/clay/m-PP nanocomposites was observed by other researchers [50,261]. 

In addition to these inner salts, a number of monomeric salt pairs have been prepared [93]. In these systems a vinyl acid such as vinyl sulfonic acid was reacted with a vinyl base such as vinyl pyridine in THF. The precipitated salt was washed and purified. Polymerization of the salt was accomplished in the aqueous solution with a thermal initiator. Other salt pairs include acrylate and acrylamide derivatives with sulfonic groups as the anionic constituents and tertiary or quaternary amino pendant groups as the cationic constituents [94]. 

Quaternary ammonium salts of 1-acryloy 1-4-methyl piperazine can be prepared by methylation with methyl chloride and dimethyl sulfate. These monomers can be polymerized by means of radical polymerization, either alone or with a comonomer [617]. A useful comonomer with appropriate monomer reactivity ratios is acrylamide. 

Figure 13 shows the compositional drift for a polymerization of acrylamide with DMAEM at 50 C. The quaternary ammonium monomer is consumed much faster than the acrylamide. Included in the figure is the predicted copolymer composition based on the reactivity ratios described in the second part of this chapter. With one exception, all the data are contained within the 95% confidence limits. We can, therefore, conclude... 

Soluble polystyrene supports differ from the terminally functionalized PEGs and polyethylene oligomers discussed above in that the catalyst moieties are attached to polystyrene via pendant groups, the loading of which can affect both the catalyst activity and separability. One example of a simple polystyrene-supported catalyst is the polystyrene copolymer-supported quaternary ammonium salts 66 and 67 [ 103]. These copolymers can be prepared with varying ratios of the styrene unit in the copolymer - the most active catalysts had 20-40 mol% of the vinylbenzylammonium groups in the copolymers. The utility of these catalysts was studied in a variety of solvents in the addition reaction of glycidyl methacrylate and carbon dioxide (Eq. 23). Polar solvents were most useful. The necessary polymer supports for preparation of catalysts 66 and 67 were prepared from chloromethylstyrene-styrene or chloromethyl-styrene-iV,JV-dimethylacrylamide copolymers that were in turn prepared by radical polymerization of the styrene or acrylamide monomers. The catalysts were recycled up to four times with small (ca. 6%) decreases in activity - de-... 

Acrylamide/dimethyidiallyl ammonium chloride copolymer Diallyidimethyl ammonium chloride with acrylamide N,N-Dimethyl-N-2-propenyl-2-propen-1-aminium chloride, polymer with 2-propenamide Poly (acrylamide-co-diallyldimethyl ammonium chloride) 2-Propen-1-aminium, N,N-dimethyl-N-2-propenyl-, chloride, polymer with 2-propenamide Quatemium-41 Classification Polymeric quaternary ammonium salt... 

Very frequently non-optimal setpoint trajectories are used for controlling reactor temperatures in batch reactors [25,39,179,180]. Reactor temperatures maybe allowed to increase from ambient temperatures up to a maximum temperature value, in order to use the heat released by reaction to heat the reaction medium and save energy (reduce energy costs). The temperature increase is almost always performed linearly, because of hardware limitations and simplicity of controller programming. After reaching the maximum allowed temperature value, reactor temperature is kept constant for a certain time interval, for production of polymer material at isothermal conditions. At the end of the batch, the reaction temperature is increased in order to reduce the residual monomer content of the final resin, usually with the help of a second catalyst. Heuristic optimum temperature trajectories were also formulated for batch polymerizations of acrylamide and quaternary ammonium cationic monomers, in order to use the available heat of reaction [181]. The batch time was split into two batch periods an isothermal reaction period and an adiabatic reaction period. 

Cationic polymers include homopolymers and cationic copolymers obtained by the polymerization of a vinylic monomer with a quaternary ammonium group or a quatemized amine with another soluble monomer in water such as acrylamide and methacrylamide. The most frequently used polymers are those derived from gum guar such as guar hydroxyl propyl triamonium chloride. They are sold under the trade names Jaguar C13S, C17, etc. [12-16]. 

Graft CO- and ter-polymers of starch have been prepared by free-radical polymerizations of vinyl monomers onto y-irradiated starch in a prototype commercial process. Products with graft contents of up to 46% were obtained by grafting acrylamide and quaternary amine-containing esters of methacrylic acid onto starch. The graft copolymers possessed retention and drainage properties superior to commercial flocculants. 

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