Polymerization of ethyl methacrylate

The enolate species 2, derived from methacrylates with bulkier ester groups than MMA, are sterically protected against the access of BujAl under the above-mentioned conditions, even when the porphyrin moiety is a non-ortho-substituted tetraphenylporphyrin. An example is shown by the polymerization of ethyl methacrylate (EMA) using 1 (X=Me) as an initiator, where the growing species have an EtO group in the terminal enolate unit 2 (R=Et). After the addition of BujAl to the system, polymerization proceeded to 100% monomer conversion within 10 min. The Mn of the produced polymer was close to the expected value, and the MWD was narrow (Table 5, run 5). A similar result was obtained for the polymerization of isopropyl methacrylate (PMA) with the 1 (X= Mel- soBujAl system, which quantitatively gave a narrow MWD poly(methacr-ylate) with a predicted Mn (Table 5, run 6). 

Table 12. Polymerization of ethyl methacrylate in toluene by BuLi at various tonperatures for24hr .Rrf." )...

Table 3. Anionic Polymerization of Ethyl Methacrylate Molecular Weight Control... 

The influence of the reaction conditions upon the stereochemistry of polymerization has been examined for a number of systems. The presence of a small amount of water increased the isotacticity of the polymerization of ethyl methacrylate in toluene at -78 °C. A new type of cyclic structure for polybutadiene-a substituted cyclopentane - was identified in polymer prepared using an organo-lithium initiator in the presence of tetramethylethylene diamine. The polymerization of 1-phenylbutadiene initiated by alkyl-lithium in hydrocarbon solvents results in 50—60% trans-, A, some 25% c/r-1,4, and 10— 25% 3,4 enchainment. When THF is employed as solvent, the corresponding values are about 80, 10, and 10%, respectively. The anionically-prepared polymers have structures very different from those formed cationically, which comprise lately 3,4 addition accompanied by extensive cyclization. The distribution of cis-and trans-1,4 structures in polyisoprene prepared using Bu Li in non-polar media has been shown by C n.ra.r. spectroscopy to be nearly random. The polymerization of fumaronitrile is initiated in benzene solution by the addition of butyl-lithium across one C N group in THF solution initiation is by transfer of an electron from BuLi. ... 

COEXISTENCE OF ACTIVE SPECIES IN ANIONIC POLYMERIZATION OF ETHYL METHACRYLATE... 

The organolanthanide initiators allowed stereospecific polymerization of ethyl, isopropyl, and t-butyl methacrylates (Table 3). The rate of polymerization and the syndiotacticity decreased with increasing bulkiness of the alkyl group in... 

Fig. B8.1.1. Variation in the fluorescence intensity of compound 1 during the polymerization of methyl methacrylate (MMA), ethyl methacrylate (EMA), n-butyl methacrylate (n-BMA) (reproduced with permission from Louftya ).

Copper bromide and pentakis-A-(heptadecafluoroundecyl)-l,4,7-triazeheptane (1 in Figure 10.9), along with an initiator, ethyl-2-bromoisobutyrate (2 in Figure 10.9), in a perfluoromethylcyclohexane-toluene biphase efficiently catalyse the polymerization of methyl methacrylate, with a conversion of 76 % in 5 h at 90 °C. The resultant polymer has a Mn = 11100 and a molar mass distribution of 1.30. After polymerization, the reaction was cooled to ambient temperature, the organic layer removed and found to contain a copper level of 0.088 % (as opposed to 1.5% if all the catalyst were to have remained in the polymer). A further toluene solution of monomer and 2 could be added,... 

The ruthenium indenylidene Schiff base complexes XXVIIIa and XXVIIId, synthesized by Verpoort, were evaluated in atom-transfer radical polymerization of methyl methacrylate. The polymerization was initiated by ethyl 2-bromo-2-methyl-... 

Polymerizations of acrylic and methacrylic esters are highly exothermic (e.g., A//polymeriZation of ethyl acrylate is 13.8 kcal/mol [2]). Generally, the heats of polymerization of acrylates are greater than those of methacrylates. 

Azad and Fitch (5) investigated the effect of low molecular weight hydrocarbon additives on the formation of colloidafr particles in suspension polymerization of methyl methacrylate and vinyl acetate. It was found that the additives n-octane, n-dodecane, n-octadecane, n-tetracosane and mineral oil exerted a thermodynamic affect depending upon water-solubility and molecular weight. Since these effects on emulsion polymerization have not been considered by the earlier investigators, we have chosen n-pentane and ethyl benzene as additives with limited water-solubility and n-octadecane, and n-tetracosane as water-insoluble ones. Seeded emulsion polymerization was chosen so that the number of particles could be kept constant throughout the experiments and only the effect of the other parameters on the rate could be determined. 

Most of the reported polyfvinyl ether) macromonomers have been prepared with a methacrylate end group which can be radically polymerized and which is non-reactive under cationic polymerization conditions [71-73]. Generally, the synthesis was based on the use of the functional initiator 30, which contains a methacrylate ester group and a function able to initiate the cationic polymerization of vinyl ethers. Such initiator can be obtained by the reaction of HI and the corresponding vinyl ether. With initiator 30 the polymerization of ethyl vinyl ether (EVE) was performed using I2 as an activator in toluene at -40 °C. The MW increased in direct proportion with conversion, and narrow MWD (Mw/Mn= 1.05-1.15) was obtained. The chain length could be controlled by the monomer to initiator feed ratio. Three poly(EVE) macromonomers of different length were prepared by this method Mn=1200,5400, and 9700 g mol-1. After complete... 

Figure 2. Isothermal polymerization of methyl methacrylate in a CSTR (1 5). a. Predicted steady-state monomer conversion vs. reactor residence time for the solution polymerization of MMA in ethyl acetate at 86 °C. h. Steady-state and dynamic experiments for the isothermal solution polymerization of MMA in ethyl acetate (solvent fraction O.k) ( ) steady states,...

Tt has been observed recently (14, 15) that catalytic concentrations of - sulfur dioxide can easily initiate the polymerization of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, and styrene at or near room temperature but fails to initiate polymerization in other monomers such as acrylonitrile, acrylamide, methyl acrylate, ethyl acrylate, vinyl acetate, and vinyl pyridine under similar conditions. However, in the presence of catalytic concentrations of sulfur dioxide and a hydroperoxide, such as tert-butyl hydroperoxide, all the above monomers polymerize readily. The results of further investigations on vinyl polymerization in the presence of low concentrations of sulfur dioxide are reported here. 

When matrix polymerization of methyl methacrylate monomer was performed in the presence of iso-PMMA or of the stereocomplex ([iso-PMMA]/ [synd-PMMA] = 1/1), the tan 6 peaks of the a-process (caused by the micro-Brownian motions of main chain) and the / -process (caused by the motions of the ester side chains of PMMA) shifted to temperature ranges which were higher by 5-10°C and 30-40 °C, respectively, as compared with synd-PMMA312. From these results, Tanzawa et al. concluded that the stereospecific association drastically restricted the motion of the ester side chains of the two stereoregular PMMAs. In addition, the mutual interlocking of the side chains of PMMA also hindered, to a certain extent, the motion of the main chains of PMMA. Furthermore, they studied the matrix polymerization of methyl acrylate (MA) and ethyl acrylate (EA) in the presence of stereoregular PMMA and found ... 

Cp2TiCl2 has been assessed as additive that controls polymer chain growth in the polymerization of methyl methacrylate.1224 Methyl methacrylate is easily polymerized in the photopolymerization with Cp2TiCl2 in a water-methanol mixture under irradiation of a 15 W fluorescent room lamp. The polymerization proceeded heterogeneously.1225 This process in the presence of 2,2 -bipyridyl, 1,10-phenanthroline, or sparteine as the chelating reagent has been studied.1226 Similar studies on the polymerization of methacrylate monomers such as methyl methacrylate, ethyl methacrylate, phenyl methacrylate, and benzyl methacrylate at 40 °C have also been performed.1227 The results of co-polymerization of methyl methacrylate and acrylonitrile indicate that this process proceeds through a radical mechanism.1228 The mechanism of the controlled radical polymerization of styrene and methyl methacrylate in the... 

In a third example of this methodology Mei et al. [65] produced a polymer containing the fibronectin-based peptide sequence GRGDS, a well-known cell adhesion sequence. This time, however, the polymerization of hydroxyethyl methacrylate was carried out on the sohd support in methyl ethyl ke-tone/propanol (7 3), resulting in a bio-hybrid with a polydispersity of 1.5. This peptide-polymer hybrid material was used as a support for the growth of mouse NIH-3T3 fibroblasts. It was shown that the cells adhered better to the polymer containing the peptide than to the unfunctionalized control polymer. This highhghts one of the many potential applications for protein-polymer hybrid materials. 

With the help of this model the researchers obtained a satisfactory agreement with experiments studying the polymerization of methyl methacrylate in bulk and ethyl methacrylate in bulk and in dimethylformamide solution. 

Macroradicals were obtained by the polymerization of ethyl acrylate in cyclohexane, styrene in hexane, vinyl acetate in decane, and methyl methacrylate in hexane. Because of the solubility of the vinyl acetate block in hexane, the ratio of the weight of vinyl acetate to that of the macroradical in poly (methyl methacrylate-b-vinyl acetate) after heating at 50°C for three days was only 30/100. By contrast, because of the insolubility of the acrylonitrile block in hexane, good yields of methyl methacrylate-b-acrylonitrile macroradicals were obtained. The ratio of the weight of the acrylonitrile block to that of the macroradical was thus 90/100 after heating the mixture for three days at 50°C in hexane. 

Similar techniques have been used to incorporate silica into various polymers. (Mineral fillers are often given hydrophobic coatings to help in their dispersion in polymers such as polyolefins.60) Methacrylatopropyltrimethoxysi-lane has been used to add the methacrylate group on to silica. The treated silica was used in the emulsion polymerization of ethyl acrylate.61 Transparent films could be formed from the product. Living polystyrene was end-capped with a triethoxysilane (5.20), after which it was used to treat silica and alumina.62... 

The copolymerization of methacrylic acid, 2-(dimethylamino)ethyl ester, and thiourea under microwave irradiation was studied by Lu et al. (Scheme 14.8) [19]. It was shown that the copolymers can be used to coordinate Cu(II) to afford coordinated copolymers which can, in turn, be used as heterogeneous catalysts in the polymerization of methyl methacrylate. The reactions were performed in a modified domestic microwave oven with a continuous power regulation. 

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