Grafting methylmethacrylate

Two types of ABD-grafted PMMA were initially prepared with different polar and electronic substituents (Fig. 2). ABD-grafted polymer 1 contains no substituent in the azobenzene para position while polymer 2 contains a para nitro group. Potentially, two synthetic routes are possible to generate ABD-grafted PMMA. In approach PMMA is first synthesized and then the ABD is grafted onto the polymer chains. In another approach, ABD-grafted methylmethacrylate monomer units are first synthesized and then polymerized in a subsequent step. 

When tertiary butyl hydrogen peroxide (TBHP) was used alone as the radical initiator, no grafting of methylmethacrylate (MMA) onto wool was observed. However, TBHP in conjunction with mineral acids, such as H2SO4, HNO3, or HCIO4 afforded good results [26]. Protonation of TBHP by the acid aided in the dissociation of TBHP to yield free radicals, which initiated grafting reaction. 

Graft polymerization of methylmethacrylate monomer onto pulps of different residual lignin contents using ceric ammonium nitrate as the initiator was carried out to study the influence of this residual lignin on the graft-ability of these pulps (Fig. 3). From this figure one can... 

To sum up, the optimum conditions for methylmethacrylate grafting onto pulp by the ceric ion redox system can be summarized as follows the grafting is done at 30°C for a 1-h reaction time, using liquor ratio 40 1, acid concentration 1%, initiator concentration 0.1%, and monomer 1 mL/g pulp. 

Strongly acidic monomers, such as nitroethylene, can only be grafted under anionic conditions. Also, anionic grafting is useful for conventional monomers such as acrylonitrile and methylmethacrylate. In addition to the... 

Partial carboxymethylation of wood pulp significantly increases its susceptibility toward grafting with acrylonitrile using the ceric ion as the initiator 146]. Studies dealing with grafting of various vinyl monomers, such as acrylonitrile, methylmethacrylate, and acrylamide, onto partially carboxymethylated cotton cellulose using tetravalent cerium as the initiator have been reported [47]. 

Graft copolymerization of methylmethacrylate onto paper wood pulp using ceric ammonium nitrate as the initiator has been studied. Different experimental conditions have been used, including both water and water-organic solvent systems. The effects of composition of the grafting medium and grafting temperature on the grafting process are examined. 

Grafting of methylmethacrylate onto cellulose using ceric ammonium nitrate (Ce ) as the initiator in a benzene-water system is also demonstrated. The grafting yield in a benzene-water system is much lower than in the case of the methanol-water system and decreases by increasing the ratio of benzene to water. This can be due to the lower polarity and wetting power of benzene, which leads to poor swelling of the cellulose. 

Although open tubular columns have been used for RPLC,42 most applications use packed columns. The most widely used column packings are formed by chemically bonding butyl (C4), octyl (C8), or octadecyl (C18) chains to a silica surface. Phenyl (Ph), cyano (CN), and amino (NH2) functionalities are also used. Polymeric packings which are finding broad acceptance include alkyl-grafted poly(methylmethacrylate) and alkyl-grafted or unmodified... 

A radical initiator based on the oxidation adduct of an alkyl-9-BBN (47) has been utilized to produce poly(methylmethacrylate) (48) (Fig. 31) from methylmethacrylate monomer by a living anionic polymerization route that does not require the mediation of a metal catalyst. The relatively broad molecular weight distribution (PDI = (MJM ) 2.5) compared with those in living anionic polymerization cases was attributed to the slow initiation of the polymerization.69 A similar radical polymerization route aided by 47 was utilized in the synthesis of functionalized syndiotactic polystyrene (PS) polymers by the copolymerization of styrene.70 The borane groups in the functionalized syndiotactic polystyrenes were transformed into free-radical initiators for the in situ free-radical graft polymerization to prepare s-PS-g-PMMA graft copolymers. 

Several examples of ion-selective electrodes with ionophores covalently attached to a self-plasticized polymeric matrix have been reported in the literature. For instance, a Ca-selective electrode with the ionophore attached to a methylmethacrylate-co-decyl methacrylate backbone was developed recently [91]. Ion exchangers such as the dodecacarborane anion have been anchored to the polymeric backbone, with grafted dodecarborane showing greatly improved retention in the polymeric phase [88],... 

Metallosupramolecular graft copolymers have been prepared from a statistical copolymer containing methylmethacrylate and a methacrylate bearing a terpyridine group in the side chain. Terpyridine end-functionalized... 

Fawcett, A. H. Foster, A. B. Hania, M. Hohn, M. Mazebedi, J. L. McGaffery, G. O. Mullen, E. Toner, D. Silicone Graft Copolymers with Acrylonitrile, Ghloroprene, Styrene, Methylmethacrylate, and an Olefin. In Synthesis and Properties of Silicones and Silicone-Modified Materials-, Clarson, S. J., Fitzgerald, J. J., Owen, M. J., Smith, S. D., Van Dyke, M. E., Eds. ACS Symposium Series 838 American Chemical Society Washington, DC, 2003 pp 318-328. 

The anionic graft polymerization of vinyl monomers onto carbon fiber or graphite powder initiated by metalized carbon fiber has been investigated. The metalation of polycondensed aromatic rings of a carbon fiber surface was achieved by treatment of the carbon fiber with BuLi in Ar,Ar,Ar, AT -tetramethylethylenediamine. The anionic polymerization of methylmethacrylate and styrene was reported. No grafting was observed when carbon fiber was treated simply with BuLi in THF or toluene [44,45]. 

Polyacetals. Simionescu and coworkers (28) have extended to polyoxy-methylene the process of grafting vinyl polymers (acrylonitrile and methylmethacrylate). They performed the synthesis using a virbomill at room temperature under vacuum (10.1 Torr). The initial monomer-polymer ratio was 1 -5/1.0 and the degree of vibromill packing 0.44. Before milling the polyoxymethylene granules were dissolved in dimethyl formamide and repredpitated with the aim of stabilizer removal and for reduction of polymer particle size (from 2-2.5 mm to 0.05-0.10 mm). Full details of the reaction have been described (40). 

Non-aqueous (or-oil-in-oil) emulsions, where the phases are two immiscible organic liquids, have received relatively little attention in the literature. Riess et al. [116-119] have studied the stabilisation of waterless systems with block and graft copolymers, where one of the liquids is a good solvent for one of the blocks and a non-solvent for the other, and vice versa. Thus, poly(styrene-b-methylmethacrylate) copolymers could emulsify acetonitrile/cyclohexane mixtures, and poly(styrene-b-isoprene) was effective for DMF/hexane systems [116]. These, however, are not HIPE systems. 

Lignin has been grafted with ethenylbenzene [43,44] (styrene), 4-methyl-2-oxy-3-oxopent-4-ene [45,46] (methylmethacrylate), 2-propenamide (acrylamide), 2-propene nitrile [47] (acrylonitrile), cationic monomers, anionic monomers, and propenoic acid ethoxylates. An index of compounds listing structure, product name, and trivial name is given in Table 3. Two types of... 

Subsequent addition of the azomonomer (2) to the growing particle results in microspheres exhibiting azo groups on the surface, which, upon addition of methylmethacrylate and heating start a grafting reaction of linear polymer chains [9]. 

Copolymerization with diazo-functionalized monomers in emulsion has been employed for the preparation of highly cross-linked poly(methylmethacrylate) lattices with diazo groups covalently fixed to the core (Figure 22). Thermal decomposition of the diazo groups allowed selective grafting of a shell [254-256]. 

Van Megen and coworkers (van Megen and Pusey 1991 van Megen and Underwood 1993) have made extensive light-scattering studies on dense suspensions of 340-nm-diameter poly(methylmethacrylate) spheres sterically stabilized by a chemically grafted... 

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