Varying dimethylacrylamide

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-... 

LIU Liu, S.Q., Tong, Y.W., and Yang, Y.-Y., Incorporation and in vitro release of doxombicin in thermally sensitive micelles made from poly(iV-isopropylacrylamide-co-A/ V-dimethylacrylamide)-6-poly(D,L-lactide-co-glycolide) with varying compositions, Biomaterials, 26, 5064, 2005. 

Table I summarizes the mechanical and physical property results for films cast from Tris(F), Di(F) and Mono(F) with varying concentrations of dimethylacrylamide (DMA) using the photoinitiator Darocur 1173 (Novartis). All of the films were transparent without the use of a co-solvent. In contrast, films cast with varying concentration of DMA from a non-fluorinated TRIS, or Tris(F) possessing a fully...

Copolymers with a statistical distribution of two or more typ>es of monomeric units This is perhaps the easiest way to create a thermosensitive p>olymer, since a fully water-soluble base polymer can usually be transformed into a thermosensitive one by the introduction of hydrophobic units. An example is the recently published case, where the LCST of a set of poly-(N,N-dimethylacrylamide)stat-(7-hydroxy-3-methyl-4-vinyl indanon cop>olymers was varied between 10° C and 85° C simply by adjusting the indanon content of the molecules between 6% and 1 While this approach is attractive, it also has some drawbacks. The resulting copolymers will vary widely in comonomer content and distribution. The result is often a broad LCST range and a nonuniform and somewhat unpredictable precipitation behavior. ... 

Fig. 4 The H PGSE spectrum obtained from poly N,N-dimethylacrylamide) gel (swelling ratio q=46.3) to which poly(ethylene glycol) (Mw=20,000) is added by varying the magnetic gradient application time ( ). The pulse sequence of the pulse magnetic gradient spin echo method is also shown.

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