Graft materials

One such system involved grafting 70 parts of methyl methacrylate on to 30 parts of an 81-19 2-ethylhexyl acrylate-styrene copolymer. Such a grafted material was claimed to have very good weathering properties as well as exhibiting high optical transmission. 

Tabata, M., Shimoda, T., Sugihara, K., Ogomi, D., Serizawa, T. and Akashi, M. (2003) Osteoconductive and hemostatic properties of apatite formed on/in agarose gel as a bone-grafting material. Journal of Biomedical Materials Research Part B Applied Biomaterials, 67B, 680-688. 

Figure 3.7. The concept of chemistry in iutcrphascs visualisation of two different ways to obtain such a material, sol-gel procedure using different reagents (left) and silica grafted materials with sufficiently long spacers (right). Solvent occupies the space between the spacers...

When the OH group in the reactant is absent or far from the double bond (reactants 6 and 1, respectively), the Ti-grafted materials displayed the best activity values. When the OH group is in the proximity of the C=C... 

The calcined iron-grafted materials exhibit high selectivity as catalysts for oxidations of alkanes, alkenes and arenes with H2O2 as the oxidants [13a]. A similar method has been used by Tilley et al. to prepare a pseudotetrahedral (Co(II) [Co(4,4 -di Bu-bipy) OSi(0 Bu)3 2]) complex grafted onto the SBA-15 surface and subsequently use it in catalytic oxidation of alkylaromatic substrates with tert-butyl hydroperoxide [14]. Unfortunately, neither iron nor cobalt surface organometaUic compounds have been tested in the recycled catalytic system. 

Treatment of various supports (Si02, AI2O3 and ZnO Tdij 130-600 °C) with an excess of the iso-propoxide derivative Ln50(0 Pr)i3 (Ln = Y, Nd and Sm) furnished mono- and bi-grafted materials 3-5 [106-109]. 

No chemical interchange should be present which would be more Indicative of grafted materials. The finger print region in the spectra showed no shift in absorbances which STOggested uniform reactions. 

Patent Number US 6103775 A1 20000815 SILANE-GRAFTED MATERIALS FOR SOLID AND FOAM APPLICATIONS... 

The dose rate affects both the yield and chain length of the grafted material. Air has a detrimental effect on grafting since it inhibits the reaction, which is consistent with other radiation-induced free radical reactions. Increasing the temperature of fhe graffing sysfem increases the yield. This is very likely because raising the temperature increases the diffusion rate of the monomer into the substrate. ... 

Although many radiation-grafted materials have been discovered, only a limited number of them have been commercially utilized. One of the first successful applications was the use of grafted films in battery separators. Other possibilities are in ion exchange resins and membranes for separation processes. The textile industry represents opportunities in improving... 

Molecular Weight of Grafted Side Chains. In previous work the wool had been hydrolyzed away from the grafted material in order to isolate the polystyrene side chains. Sodium hydroxide was used with good results however, about one-half of the polystyrene was soluble in only such solvents as dimethyl formamide and benzene-methanol mixtures. Infrared examination showed the presence of groupings charac-... 

Reaction of AMPS with benzaldehyde results in a rapid (20-30s) formation of the corresponding imine. Such a reaction takes several days in the case of the HMS material. Similarly, the alkylation of the nitrogen with e g. benzyl chloride is far more rapid (by a factor of several hundred) in the case of the grafted material. Thus, the amine groups in the new materials do not appear to display any significant nucleophilicity, despite their similar basic... 

Table 2 reports the catalytic activities of the catalysts prepared for 2.6-DTBP oxidation. All the titanium grafted materials were active as catalysts for liquid phase oxidation of 2.6-DTBP, and catalytic activity decreased in the order of MCM-48 (24.5% conversion) > HMS (22.8%) > KIT-1 (16.0%) > MCM-41 (14.3%) > SBA-1 (5%). Apparently. 3 dimensional channel system of MCM —48, and HMS with small particle size and textual mesoporosity proved to be useful in liquid phase reaction [1,2,3], Chemical analysis of the titanium-grafted SBA-1 by EDX showed far less titanium at the surface than the others it seems surface nature of SBA-1 synthesized in acidic medium is different from the rest. All Ti-grafted samples suffered from titanium leaching during the liquid phase oxidation HMS host resulted in over 4 % loss in metal content while the rest showed 2%. 

The high acidity of the unique sulfonic acid function of Nafion can also be utilized by tethering perfluoroalkanesulfonic acid groups to the surface of various silicas. Two approaches have been described to prepare such hybrid organic-inorganic materials. The grafted materials 3 have been prepared by reacting preformed silica materials (MCM-41, SBA-15) with sultone 2 [Eq. (2.31)].165 Co-condensation of tetraethoxy-silane with 4 in the presence of dodecylamine template, in turn, furnished the HMS-based material 5 [Eq. (2.32)].166,167... 

Experiment Surface area (rn2/g Y Mean pore diameter (A)" Pore volume (cm3/g) wt (mg) Wj (mg) Grafted material (%y... 

Numerous other properties, such as ion-exchange, mildew resistance, dimensional stability, coefficient of friction and electrical properties can also be imparted to cellulose by grafting. The presence of cellulose has also been shown to impart biodegradability to the cellulose-synthetic polymer grafted materials. 

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