Methyl methacrylate complex

The most significant observation in the radical copolymerization of methyl methacrylate with vinylidene chloride in the presence of zinc chloride is the increase in the Q and e values of methyl methacrylate, the increase in the rx value of methyl methacrylate, and the decrease in the r2 value of vinylidene chloride (30). Although it has been proposed that these results arise from the increased reactivity of the complexed methyl methacrylate monomer, a more likely explanation is the homopolymerization of a methyl methacrylate-complexed methyl methacrylate complex accompanied by the copolymerization of methyl methacrylate with vinylidene chloride. 

Photo-induced polymerization of hydroxypropyl-P-CD/methyl methacrylate complex, i.e. HP-P-CD/MMA was performed in aqueous solution, at room temperature with Irgacure 2959, i.e. 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone serving as a photoinitiator [75]. The atom transfer radical polymerization (ATRP) and reversible addition fragmentation chain transfer (RAFT) [76] methods are also used to perform polymerization of the CD/guest monomer complexes in aqueous solutions. 

In the case of polar polymers the situation is more complex, since there are a large number of dipoles attached to one chain. These dipoles may either be attached to the main chain (as with poly(vinyl chloride), polyesters and polycarbonates) or the polar groups may not be directly attached to the main chain and the dipoles may, to some extent, rotate independently of it, e.g. as with poly(methyl methacrylate). 

Blending of ABS with an acrylic material such as poly(methyl methacrylate) can in some cases allow a matching of the refractive indices of the rubbery and glassy phases and providing that there is a low level of contaminating material such as soap and an absence of insoluble additives a reasonable transparent ABS-type polymer may be obtained. More sophisticated are the complex terpolymers and blends of the MBS type considered below. Seldom used on their own, they are primarily of use as impact modifiers for unplasticised PVC. 

The participation of a monomer molecule in the initiation step of polymerization has not been required in the examples described so far. Tris(thiocyanato) tris(pyri-dine) iron(III) complex forms a complex with methyl methacrylate [46]. By subjecting the compound to UV radiation, the complex decomposes to give SCN as the initiating radical. 

Hydroxy-containing polymers such as poly(methyl-methacrylate-co-hydroxyethyl methacrylate) [65,66] or secondary cellulose acetate [67,68] were used for this purpose. Vanadium (V) 8-hydroxy quinoline-hydroxy-ethyl methacrylate adduct, prepared by condensation of the latter with a VOQ2OH complex, is polymerized to... 

The polymerization of methyl methacrylate (MMA) by Cu(ll) amidinate complexes (Scheme 222) in combination with alkyl aluminum complexes has been reported. The preferred alkylating agent is methylalumoxane (MAO) in... 

Figure 2.1 Relationship between rate of reaction, Rp, and initiator concentration [I], for isoquinoline-bromine complex in methyl methacrylate (J. W. Nicholson, unpublished results, 1977)...

The PBE dendron has a glass transition at about 40 °C and is soluble in various organic solvents (e.g., THF, acetone, toluene). It is therefore a moldable, thermoplastic, film-forming material. This practical feature is maintained for the lanthanide-cored dendrimer complexes. The complexes are partially miscible with poly(methyl methacrylate), affording transparent luminescence compositions by mixing in solvent. 

It is known that the polymerization of MMA. .. SnCl4 and (MMA)2. .. SnCl complexes (MMA = methyl methacrylate) yields a polymer which predominantly exhibits an isotactic structure90). From the analogy between these complexes and those discovered by the author of this article (MA. .. SnR3), it can be suggested that free-radical copolymerization of MA with trialkylstannyl methacrylates yields copolymers mainly exhibiting configuration19). 

A considerable viscosity increase in copolymers of tributylstannyl methacrylate with methyl methacrylate, butyl acrylate and styrene upon prolongated storage has been observed and special agents to eliminate this effect have been proposed 108). It is likely that the destruction of intermolecular coordination complexes formed by involvement of tin and carbonyl groups in comonomer units takes place in this case. 

The mechanism proposed for the polymerization of styrene initiated by Zr (benzyl) 4 differs from that proposed for the polymerization of methyl methacrylate initiated by chromium allyls (12, 44)- In these papers it was considered that the concentration of complex (I) was comparable to the catalyst concentration, a fact which now seems unlikely in view of the... 

A range of rare earth metal complexes were subsequently shown to catalyze ethylene polymerization and, on occasion, living characteristics have been reported.226-228 Dimeric hydrides such as (79)—(82) are extremely active with turnover numbers > 1800 s-1 recorded for (79) at room temperature. The samarium hydride (82) also effects the block copolymerization of methyl methacrylate (MMA) and ethylene 229 further discussion may be found in Section 9.1.4.4. 

The highly syndiospecific-living polymerization of methyl methacrylate has been initiated by the neutral bis(pentamethylcyclopentadienyl)lanthanide-alkyl or -hydride complexes [215,216]. The plausible reaction mechanism is shown in Scheme XI. 

The synthesis of monodisperse high molecular weight syndiotactic poly(methyl methacrylate) mentioned above was possible at a polymerization temperature as low as — 95 °C [3]. However, methods to synthesize it at a relatively high temperature or to synthesize its isotactic counterpart remain to be found. When the latter is made available, the synthesis of stereo-complexes of poly(methyl methacrylate) will become the focus of considerable interest. 

We were recently able to isolate and structurally characterize a series of [CuI(PMDETA)(7i-M][BPh4] complexes (M = styrene, methyl acrylate, methyl methacrylate, and 1-octene) [110,111]. Molecular structures of [Cu PMDETA) (71-methyl acrylate)] [BPhJ and [CuI(PMDETA)(7i-styrene)][BPh4] are shown in Fig. 5. In all complexes, PMDETA acted as a tridentate ligand, while the... 

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