Methyl acrylate reactivity ratios

Kress, A.O., Mathias, L.J. and Cei, G., Copolymers of styrene and methyl a-(hydroxymethyl)acrylate reactivity ratios, physical behavior, and spectral properties, Macromolecules, 1989, 22, 537. 

The data in Table 7.6 list the mole fraction of methyl acrylate in the feedstock and in the copolymer for the methyl acrylate (Mi)-vinyl chloride (M2) system. Use Eq. (7.54) as the basis for the graphical determination of the reactivity ratios which describe this system. 

Vinyhdene chloride copolymerizes randomly with methyl acrylate and nearly so with other acrylates. Very severe composition drift occurs, however, in copolymerizations with vinyl chloride or methacrylates. Several methods have been developed to produce homogeneous copolymers regardless of the reactivity ratio (43). These methods are appHcable mainly to emulsion and suspension processes where adequate stirring can be maintained. Copolymerization rates of VDC with small amounts of a second monomer are normally lower than its rate of homopolymerization. The kinetics of the copolymerization of VDC and VC have been studied (45—48). 

The ratio of the two diastereomeric products 190 and 191 was found to depend on the reaction temperature and reaction time. The addition of acrolein or methyl vinyl ketone proceeded smoothly, but in the case of methylacrylate or acrylonitrile the reaction did not proceed under the same conditions (EtsN THF 30°C). An accompanying AMI calculation of these Q ,/3-unsaturated compounds [LUMOs for acrolein, -0.13877 for methyl vinyl ketone, -0.06805 (s-trans) for methyl acrylate, -0.01413 (s-tmns) for acrylonitrile, 0.04971] suggested the low reactivity of methyl acrylate and acrylonitrile toward the Michael reaction (99H1321). 

For the remaining three systems, styrene-vinyl acetate, vinyl acetate-vinyl chloride, and methyl acrylate-vinyl chloride, one reactivity ratio is greater than unity and the other is less than unity. They are therefore nonazeotropic. Furthermore, since both ri and 1/7 2 are either greater than or less than unity, both radicals prefer the same monomer. In other words, the same monomer—styrene, vinyl chloride, and methyl acrylate in the three systems, respectively—is more reactive than the other with respect to either radical. This preference is extreme in the styrene-vinyl acetate system where styrene is about fifty times as reactive as vinyl acetate toward the styrene radical the vinyl acetate radical prefers to add the styrene monomer by a factor of about one hundred as compared with addition of vinyl acetate. Hence polymerization of a mixture of similar amounts of styrene and vinyl acetate yields an initial product which is almost pure polystyrene. Only after most of the styrene has polymerized is a copolymer formed... 

Compositionally uniform copolymers of tributyltin methacrylate (TBTM) and methyl methacrylate (MMA) are produced in a free running batch process by virtue of the monomer reactivity ratios for this combination of monomers (r (TBTM) = 0.96, r (MMA) = 1.0 at 80°C). Compositional ly homogeneous terpolymers were synthesised by keeping constant the instantaneous ratio of the three monomers in the reactor through the addition of the more reactive monomer (or monomers) at an appropriate rate. This procedure has been used by Guyot et al 6 in the preparation of butadiene-acrylonitrile emulsion copolymers and by Johnson et al (7) in the solution copolymerisation of styrene with methyl acrylate. 

Ferrocenylmethyl acrylate (FMA) and 2-ferrocenylethyl acrylate (FEA) have been synthesized and copolymerized with styrene, methyl acrylate, and vinyl acetate [C. U. Pittman, Jr., Macrmolecules, 4, 298 (1971)]. The following monomer reactivity ratios were found ... 

Copolymers. Vinyl acetate copolymenzes easily with a few monomers, e g, ethylene, vinyl chloride, and vinyl neodecanoate, which have reactivity ratios close to its own. Block copolymers of vinyl acetate with methyl methacrylate, acrylic acid, acrylonitrile, and vinyl pyrrolidinone have been prepared by copolymerization in viscous conditions, with solvents that are poor solvents for the vinyl acetate macroradical,... 

Labelled monomers have been used in co-polymerizations for analysis of the resulting co-polymers and consequent determination of monomer reactivity ratios (15, 16). This technique is of particular value when the compositions of the different monomer units are rather similar or when the co-polymer contains only very small amounts of one of the monomers. These points can be appreciated by considering calculations on co-polymers of methyl methacrylate and methyl acrylate summarized in Table 1. The analyses have been calculated ignoring contributions of end-groups it assumed that the acrylate ester is labelled with carbon-14 and that specific activities are expressed in units such as curies/g of carbon. 

Table 6.3 Summary of reactivity ratios determined by various methods for the bulk copolymerization of styrene with methyl a-hydroxymethyl acrylate at T = 80 °C [226]...

Alkenyl complexes can undergo cycloaddition with dienes. Thus the complex 6, prepared from vinyllithium, can be used as an alternative to the less reactive methyl acrylate. The cycloadducts can undergo various useful transformations (Scheme I). The reaction of 6 with cyclopentadiene gives a mixture of the endo- and exo-adducts in the ratio 94 6 in 78% yield. 

Experimental System The copolymerisation of styrene with methyl acrylate in toluene using azo-bis-iso- butyronitrile (AIBN) was selected as the model experimental system because the overall rate of reaction is relatively fast, copolymer analysis is relatively simple using a variety of techniques and the appropriate kinetic and physical constants are available in the literature. This monomer combination also has suitable reactivity ratios (i = 0.76 and r4 =0.175 at 80 C),(18) making control action essential for many different values if compositionally homogeneous polymers are to be prepared at higher conversions in a semi-batch reactor. 

The acrylate- and methacrylate-derivatized r 5-(benzene)tricarbonylchromium monomers 20 65,66,68,72 21,69>72 and 2273 (Scheme 1.2) were synthesized from benzyl alcohol or 2-phenylethanol when reacted with Cr(CO)6. The alcohols were esterified with either acrylyl or methacrylyl chloride in ether/pyridine and purified by multiple recrystallizations from CS2. Homopolymerizations proceeded in classic fashion with no special electronic effects from the rr-complexed Cr(CO)3 moiety.65,73 Acrylate 20 was copolymerized with styrene and methyl methacrylate and the reactivity ratios were obtained.65 Acrylate 21 and methacrylate, 22, copolymerized readily with styrene, methyl acrylate, acrylonitrile, and 2-phenylethyl acrylate to give bimodal molecular-weight distributions using AIBN initiation.69 Copolymerization of 20 with ferrocenylmethyl acrylate, 2, generates copolymers with varying mole ratios of two transition metals, Cr and Fe (see structure 34).65... 

Novel iron carbonyl monomer, r)4-(2,4-hexadien-l-yl acrylate)tricarbonyl-iron, 23, was prepared and both homopolymerized and copolymerized with acrylonitrile, vinyl acetate, styrene, and methyl methacrylate using AIBN initiation in benzene.70,71 72 The reactivity ratios obtained demonstrated that 23 was a more active acrylate than ferrocenylmethyl acrylate, 2. The thermal decomposition of the soluble homopolymer in air at 200°C led to the formation of Fe203 particles within a cross-linked matrix. This monomer raised the glass transition temperatures of the copolymers.70 The T)4-(diene)tricarbonyliron functions of 23 in styrene copolymers were converted in high yields to TT-allyltetracarbonyliron cations in the presence of HBF4 and CO.71 Exposure to nucleophiles gave 1,4-addition products of the diene group.71... 

In the present work, the copolymerization of acrylamide (AAM) with three cationic comonomers DADMAC, dimethylaminoethyl methacrylate (DMAEM), and dimethylaminoethyl acrylate (DMAEA) (the latter two qua-temized with methyl chloride) was investigated. The reactivity ratios were determined by using continuous solution polymerization with the error-invariables method, a technique that provides estimates of the joint confidence... 

The reason why certain bromides are more active than iodides in the attack to palladium(II) is probably connected to steric effects. We ascertained that at room temperature the order of reactivity of aryl iodides and bromides with palladium(O) and paUadiiun(II) is the same (I>Br), so the difference is hkely to lie in the easier accessibility of the reaction center of the palladacycle to suitably activated bromo derivatives than to o-alkyl-substituted aryl iodides, which are considerably bulkier. We ascertained that several groups are compatible as shown in Table 4, referring to the reaction of o-substituted aryl iodides, substituted aryl bromides, norbornene, methyl acrylate, K2CO3, and Pd(OAc)2 in the molar ratio 50 50 50 80 120 1. 

A study of the microstructure of copolymers made use of a simple solution procedure for the copolymerization of methyl acrylate (MA) with A-vinylcarba-zole (NVK). The ratio of the feed composition ranged from (0.1429 moles of MA to 1.00 of NVK) to (7 moles of 1 of NVK)—a 49-fold range in composition. The experiments were carried out to high conversions [41]. Preparation 2-8 is based on this work. The reactivity ratios calculated from this series were approximately... 

Some recent NMR studies on the copolymerization of allyl acetate with methyl methacrylate, butyl acrylate, and styrene reported their reactivity ratios (cf Table IXb) [65]. The reported error terms, if we assume them to be standard deviations, are quite large with respect to the ri term. Therefore it is problematic whether these numbers are really meaningful. It would seem to us that the large f-2 terms imply that substantially only homopolymers of these three vinyl monomers form. This situation is modified in the case of allyl methacrylate or allyl acrylate copolymers, as will be mentioned below. With these acrylic derivatives, copolymerization depends on the acrylic bonds primarily with modifications due to the allylic hydrogen. Subsequently, the allylic units in a copolymer of allyl methacrylate with butyl methacrylate, for example, will be the sites for crosslinking. 

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