Methyl methacrylate grafting initiators

Yamamoto K, Tanaka H, Sakaguchi M, Shimada S. Well-defined poly(methyl methacrylate) grafted to polyethylene with reverse atom transfer radical polymerization initiated by peroxides. Polymer 2003 44(25) 7661-9. 

Ma, W., Otsuka, H., Takahara, A., 2011a. Poly(methyl methacrylate) grafted imogoUte nano-tuhes prepared through surface-initiated ARGET ATRP. Chemical Communications 47, 5813-5815. 

Group-Transfer Polymerization. Living polymerization of acrylic monomers has been carried out using ketene silyl acetals as initiators. This chemistry can be used to make random, block, or graft copolymers of polar monomers. The following scheme demonstrates the synthesis of a methyl methacrylate—lauryl methacrylate (MMA—LMA) AB block copolymer (38). LMA is CH2=C(CH2)COO(CH2) CH2. 

An effective method of NVF chemical modification is graft copolymerization [34,35]. This reaction is initiated by free radicals of the cellulose molecule. The cellulose is treated with an aqueous solution with selected ions and is exposed to a high-energy radiation. Then, the cellulose molecule cracks and radicals are formed. Afterwards, the radical sites of the cellulose are treated with a suitable solution (compatible with the polymer matrix), for example vinyl monomer [35] acrylonitrile [34], methyl methacrylate [47], polystyrene [41]. The resulting copolymer possesses properties characteristic of both fibrous cellulose and grafted polymer. 

ARGET ATRP has been successfully applied for polymerization of methyl methacrylate, ft-butyl acrylate and styrene in the presence of Sn(EH)2 (10 mol% vs. alkyl halide initiator or 0.07 mol% vs. monomer) [164,165]. For all monomers, polymerizations were well controlled using between 10 and 50 ppm of copper complexes with highly active TPMA and Me6TREN ligands. ARGET ATRP has also been utilized in the synthesis of block copolymers (poly(n-butyl acrylate)— -polystyrene and polystyrene-Z -poly(n-butyl acrylate) [164,165] and grafting... 

Peracetic acid, formed in situ from acetic acid and hydrogen peroxide in acid aqueous solution, was found to initiate graft copolymerization of vinyl monomers, e.g. methyl methacrylate and 4-vinyl pyridine, onto wood and cellulosic fibers at a good rate (1-3 h time) at 60°C2. The initiati on reaction is not specific for grafting and considerable amounts of homopolymer is formed. 

In 1962, Kimura, Takitani and Imoto (1) found that an aqueous solution of starch could easily polymerize methyl methacrylate (MMA) and about a half of polymerized MMA grafted on starch. This novel polymerization was called as "uncatalyzed polymerization". Since then, a lot of macromolecule was applied, instead of starch, and many of them were effective to initiate the radical polymerization of MMA. 

During the last 5 years, there have been several reports of multiblock copolymer brushes by the grafting-from method. The most common substrates are gold and silicon oxide layers but there have been reports of diblock brush formation on clay surfaces [37] and silicon-hydride surfaces [38]. Most of the newer reports have utilized ATRP [34,38-43] but there have been a couple of reports that utilized anionic polymerization [44, 45]. Zhao and co-workers [21,22] have used a combination of ATRP and nitroxide-mediated polymerization to prepare mixed poly(methyl methacrylate) (PMMA)Zpolystyrene (PS) brushes from a difunctional initiator. These Y-shaped brushes could be considered block copolymers that are surface immobilized at the block junction. 

Tsubokawa et al. (12-14) have introduced radical sources of azo or peroxy groups by another methods, and successively conducted the radical polymerization of vinyl compounds, such as styrene or methyl methacrylate, to give polymer-grafted particles see Reaction (3). The grafting by the radical polymerization of methyl methacrylate, initiated from a peroxy group introduced on silica, takes place at relatively high efficiency, compared with those from azo group-introduced particles. 

Bischof (16) used the macroradicals resulting from vibromilling as initiators for synthesis of block and graft copolymers of poly(methyl methacrylate) with poly(vinyl chloride) with polyacrylonitrile. 

The results that have been found for these four monomers are rather surprising For three of the monomers, methyl acrylate, acrylic acid, and methacrylic acid, both BPO and AIBN will initiate the graft copolymerization while for methyl methacrylate only BPO gives a reasonable yield of the graft copolymer. Even more surprising is the fact that for the two esters, no ungrafted SBS is found while for the acids only a small amount of the SBS is actually involved in the graft copolymerization. 

A constant fraction of the monomer is converted to graft copolymer for the reactions of methyl methacrylate and methyl acrylate with SBS this is independent of the amount of monomer and the amount of initiator. Both homopolymer and graft copolymer are formed and 25 - 30% of the monomeric methyl methacrylate reacts to form the graft copolymer while the remainder forms homopolymer the fraction of graft copolymer is close to 40% for methyl acrylate. This is also true for the reaction of acrylonitrile with polystyryllithium, here the amount of graft copolymer is a little lower, in the range of 15 - 20%. ... 

D. D. Jiang and C. A. Wilkie, Chemical initiation of graft copolymerization of methyl methacrylate onto... 

The first application of the ferrous ion-hydrogen peroxide initiation for polymerizing vinyl monomers on and into cellulose fibers has been reported by Landeias and Whewell (41) in three successive papers. They are apparently the first who applied the "anchored catalyst technique, which other people have termed "in situ polymerization to cellulose grafting. The authors internally deposited methyl methacrylate, acrylonitrile, styrene, methyl vinyl ketone and methacrylamide in amounts between 10 and 80%. No attempt had been made to determine if actual grafting had occurred. In 1961 Richards (42) studied this question in great detail. Products obtained by polymerization of acrylonitrile and of styrene in viscose rayon were acetylated. Fractionation of... 

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