Poly alkyl methacrylates

In polymerization of methacrylates, the adducts formed by addition to the macromonomer radicals are relatively unreactive towards adding further monomer 

Values of CP measured in the presence of added PMMA (for example) will depend on how the PMMA was prepared and its molecular weight (i.e. on the concentration of unsaturated ends). PMMA formed by radical polymerization in the presence of a good H-donor transfer agent (or by anionic polymerization) would have only saturated chain ends. These PMMA chains should have a different transfer constant to those formed by normal radical polymerization where termination occurs by a mixture of combination and disproportionation. This could account for some of the variation in the values of CP for this polymer 

The self-reactions of 2 carboalkoxy 2 propyl radicals (8-10) have been examined. The results of these studies are reported in Table 5.3. Combination is slightly favored over disproportionation, fhe value of for 8 was found to be essentially independent of temperature. 

Disproportionation increases in the series where the ester is methyl ethyl butyl suggesting that this process is favored by increasing the bulk of the ester alky group. This trend is also seen for polymeric radicals (Section 

Bizilj et reported that disproportionation is more important for oligomeric radicals. While combination products were unequivocally identified, analytical difficulties prevented a precise determination of the disproportionation products. Accordingly, they were only able to state a maximum value of Their data show that 1.85 for the self reaction of 11 and 1.50 for reaction between 8 and 11. 

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Fig. 13. Thickening of lOW base stock to multigraded oil with polymer additives. A, high mol wt poly(alkyl methacrylate) B, low mol wt poly(aLkyl...

A large number of organic acrylic ester polymer have been prepared in the laboratory. Poly (methyl acrylate) is tough, leathery and flexible. With increase in chain length there is a drop in the brittle point but this reaches a minimum with poly-(n-octyl acrylate) (see Figure 15.12.). The increase in brittle point with the higher acrylates, which is similar to that observed with the poly-a-olefins and the poly(alkyl methacrylate)s, is due to side-chain crystallisation. 

Table 8.2 Effect of Solvent on Tacticity of Poly(alkyl methacrylate) at -40 °C94...

Poly (alkyl methacrylate) macromonomers are formed by reaction of the living polymer with VBC. This method was shown to be free of side reactions and quantitative, in spite of the low nucleophilicity of the carbanionic site involved 72,75). 

Thermogravimetric analysis (TGA), poly(alkyl methacrylates), 270,273/ Toluene... 

This section provides an overview of properties of polymer monolith columns related to 2D-HPLC. Monolithic organic polymer columns, having longer history than silica monoliths, have been reviewed in detail recently by S vec and by Eeltink including their preparation methods and performance (Eeltink et al., 2004 Svec, 2004a). Polymer monolith columns commercially available include polyfstyrene-co-di vinyl benzene) (PSDVB) columns and poly(alkyl methacrylate) columns. 

Morimoto, K. and Suzuki, S., "Ultraviolet Irradiation of Poly(alkyl Acrylates) and Poly(alkyl Methacrylates)", J. Appl. Polym. Sci., 1972, 16, 2947-2961. 

Li G, Mianami N (2003) Increase of photoluminescence from fullerenes-doped poly (alkyl methacrylate) under laser irradiation. Journal of Photoluminescence 104 207. 

Unlike the poly(alkyl methacrylates) that degrade by random chain scission, PMMA undergoes degradation through unzipping when heated. 

McKee MG, Elkins CL, Park T, Long TE. Influence of random branching on multiple hydrogen bonding in poly(alkyl methacrylate)s. Macromolecules 2005 38 6015-6023. 

Fig. 7a,b. Miscibility maps calculated at 25 °C for poly(alkyl methacrylate ) blended with a STVPh and b STHFS [83]... 

Polypyrrole/poly(ethylene-co-vinyl acetate) conducting composites with improved mechanical properties were prepared by a similar method [167], In addition, polyaniline/polystyrene [168] and polyaniline/poly(alkyl methacrylate) [169] composites have been synthesised. A solution of persulphate in aqueous HC1 was added to an o/w HIPE of polymer and aniline in an organic solvent, dispersed in aqueous SDS solution, causing aniline polymerisation. Films were processed by hot- or cold-pressing. 

Eudragit (Rohm/Pharma Polymers, Darmstadt, Germany) is a class of polymer that will dissolve at specific pH values. Eudragit polymers are members of the poly(alkyl methacrylate) family of polymers. This family of polymers has a wide degree of properties due to the many modifications used in the formation of the polymers. The dissolution properties are based on the modification of the carboxylic moieties of methacrylic acid. The degree of modification and the specific modification determine at what pH and how quickly the polymers dissolve. 

J.C. Cho, G. Cheng, D. Feng, R. Faust, R. Richard, M. Schwarz, K. Chan, and M. Boden, Synthesis, characterization, properties, and drug release of poly(alkyl methacrylate-b-isobutylene-b-alkyl methacrylate), Biomacromolecules, 7(ll) 2997-3007, November 2006. 

The partial rotation of side chains12,13) COOR sets in (Fig. 4) at about Ip = 280 K, if R = CH3 QH5 C3H7 C4H9 consequently. Tp of poly(alkyl methacrylates) is not... 

M. S. Gluckman and M. J. Kampf The effect of the alkyl group on the irradiation grafting of methyl methacrylate to poly(alkyl methacrylates), J. Polymer Sci. 38, 417 (1959). 

The theoretical results were applied to the systems poly(alkyl methacrylate)s. Alkyl = Me, Et, iBu in the mixed solvent methanol (B) + 1,4-dioxane (A) [98],... 

Figure 1.17 shows the comparison of theory and experiment for preferential adsorption coefficient X of poly(alkyl methacrylate)s in 1,4-dioxane-methanol. 

A quantitative agreement was found between theory and the experimental results dealing with the dependence of the preferential adsorption coefficient X with the composition, in the cases that were chosen as examples Poly(alkyl methacrylates )/l, 4 - dioxane/methanol [120],... 

Fig. 1.17 Comparison of theory and experiment for preferential adsorption coefficient, X, of poly(alkyl methacrylate)s in 1,4-dioxane-methanol. (pso = methanol volume fraction). Points Experimental results from ref. [6], (o) PMMA (alkyl = Me) (A) PEMA (Et) ( ) PiBM (iBu). Association equilibria theory. (2-A) Calculated with the parameter values shown in Table I and numbered as 4-6, Curves (a) PMMA (b) PEMA, (c) PiBMA. (2-B) Calculated with the parameter values shown in Table I and numbered as 10-12. Curves (a) PMMA (b) PEMMA (c) PiBMa. (From ref. [120])...

A f3 relaxation is observed as a shoulder of the a relaxation in all the polymers under study in this section. This type of relaxation is commonly attributed to rotational motions of the lateral chain as a whole as in poly (alkyl methacrylates) [34—40,60,61]. 

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