Functionalization by grafting

Virklund, C., Nordstrom, A., Irgum, K. (2001). Preparation of porous poly(styrene-co-divinylbenzene) Monoliths with controlled pore size distributions initiated by stable free radicals and their pore surface functionalization by grafting. Macromolecules 34, 4361-... 

In dentistry, silicones are primarily used as dental-impression materials where chemical- and bioinertness are critical, and, thus, thoroughly evaluated.546 The development of a method for the detection of antibodies to silicones has been reviewed,547 as the search for novel silicone biomaterials continues. Thus, aromatic polyamide-silicone resins have been reviewed as a new class of biomaterials.548 In a short review, the comparison of silicones with their major competitor in biomaterials, polyurethanes, has been conducted.549 But silicones are also used in the modification of polyurethanes and other polymers via co-polymerization, formation of IPNs, blending, or functionalization by grafting, affecting both bulk and surface characteristics of the materials, as discussed in the recent reviews.550-552 A number of papers deal specifically with surface modification of silicones for medical applications, as described in a recent reference.555 The role of silicones in biodegradable polyurethane co-polymers,554 and in other hydrolytically degradable co-polymers,555 was recently studied. 

We proved this presumption on blends of PA6 with LDPE and HOPE and on a blend of PE with ethylene-propylene rubber (EPDM). The polyolefin components were functionalized by grafting 1 wt% of itaconic acid (lA) (51,53). Functionalization and preparation of the blends were performed in a static mixer assembled onto the Brabender plastograph (51,73). Grafting with simultaneous cross-linking of PO resulted in a sharp reduction of MFl values and r] of their melt. It can be seen in Table 18.1 that g-POs possess much higher melt viscosities than PA6. The viscosity of LDPE exceeds r] of PA6 by two decimal orders. of PA6 is twice as low as that of... 

The capped radical-generating centers of living polymerization, located on the surface of monolith pores, can be further used for functionalization, by grafting various monomers, for example, vinylbenzyl chloride, tert-butyl methacrylate, or vinylpyridine [393], as well as 2-hydroxyethyl methacrylate and 3-sulfopropyl methacrylate [394]. Another possibiHty for changing the surface chemistry is the involvement of pendent double bonds that remain on the pore surface of highly crossUnked styrene-DVB rods, in a variety of chemical reactions these have been reviewed by Hubbard et al. [395]. 

Work done by Gong et al. [66] is similar to the work by Maruyama et ah, above. They functionalize butyl rubber with succinic anhydride to improve the compatibility of butyl rubber with an organoclay. Barrier performance of the rubber nanocomposite increases with the amount of succinic anhydride modification. In a companion publication [67], butyl rubber is functionalized by grafting maleic anhydride onto the polymer chain with peroxide. The same organoclay is utilized in this work as well to form the rubber nanocomposite. Barrier performance of the butyl rubber is significantly enhanced. 

PA-66/PP-g-COOH Mechanical properties/PP functionalized by grafting with a peroxide-COOH/ comparison to blends containing PP-g-MA in place of PP-g-COOH Bohn et al. 2001... 

Schematic representation of PET pore functionalization by grafting from of stimuli-responsive PNIPAAm via two different strategies and change of effective pore diameter by increasing/ decreasing the temperature around the LCST (32°C). (From Friebe, A., and Ulbricht, M., Langmuir, 23,10316-10322,2007.)...

Functionalization by grafting and copolymerization is the most frequently seen method for preparing reactive polymers for blending applications. 

The effects of CNT s surface chemistry on the bubble density were also studied (Chen et al., 2012). In their study, the oxidized CNTs (M20 and MlOO) were functionalized by grafting with glycidyl phenyl ether (GPE) (Figure 1.14a). The GPE functionalized CNTs (P20 and PlOO) would have the same aspect ratio as the parent oxidized CNTs. They found that at the same nanotube concentration, the nanocomposite foams with GPE grafted CNTs had a bubble density several times higher than that of nanocomposite foams with oxidized CNTs under a series of foaming... 

Scheme 10.2 Top Schematic representation of external surface functionalization by grafting to as-synthesized mesoporous silica. Bottom Scanning electron microscopy images of ASNCs (left) and mesoporous silica spheres (right). The corresponding CLSM images taken after fluorescent labeling of...

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