Methylacrylate

The action of sulphuric acid alone upon acetone cyanohydrin affords a-methylacrylic acid. The methyl methacrylate polymers are the nearest approach to an organic glass so far developed, and are marketed as Perspex (sheet or rod) or Dialcon (powder) in Great Britain and as Plexiglass and Luciie in the U.S.A. They are readily depolymerised to the monomers upon distillation. The constitution of methyl methacrylate polymer has been given as ... 

The principal monomer of nitrile resins is acrylonitrile (see Polyacrylonitrile ), which constitutes about 70% by weight of the polymer and provides the polymer with good gas barrier and chemical resistance properties. The remainder of the polymer is 20 to 30% methylacrylate (or styrene), with 0 to 10% butadiene to serve as an impact-modifying termonomer. 

Acryhc stmctural adhesives have been modified by elastomers in order to obtain a phase-separated, toughened system. A significant contribution in this technology has been made in which acryhc adhesives were modified by the addition of chlorosulfonated polyethylene to obtain a phase-separated stmctural adhesive (11). Such adhesives also contain methyl methacrylate, glacial methacrylic acid, and cross-linkers such as ethylene glycol dimethacrylate [97-90-5]. The polymerization initiation system, which includes cumene hydroperoxide, N,1S7-dimethyl- -toluidine, and saccharin, can be apphed to the adherend surface as a primer, or it can be formulated as the second part of a two-part adhesive. Modification of cyanoacrylates using elastomers has also been attempted copolymers of acrylonitrile, butadiene, and styrene ethylene copolymers with methylacrylate or copolymers of methacrylates with butadiene and styrene have been used. However, because of the extreme reactivity of the monomer, modification of cyanoacrylate adhesives is very difficult and material purity is essential in order to be able to modify the cyanoacrylate without causing premature reaction. 

The simplest monomer, ethylenesulfonic acid, is made by elimination from sodium hydroxyethyl sulfonate and polyphosphoric acid. Ethylenesulfonic acid is readily polymerized alone or can be incorporated as a copolymer using such monomers as acrylamide, aHyl acrylamide, sodium acrylate, acrylonitrile, methylacrylic acid, and vinyl acetate (222). Styrene and isobutene fail to copolymerize with ethylene sulfonic acid. 

Acryflc coating powders have achieved some success in Japan utilizing resins having gflcydyl methylacrylate functionality cured with C q—0 2 dicarboxyflc acids (49). Hybrid polyester—acryflc coating powders have also been reported in which an acid functional polyester resin coreacts with a glycidyl-containing acryflc polymer (50). Hydroxyl functional acryflc resins cured with blocked isocyanates have also been available for many years in the United States and achieved some commercial success as appliance finishes. 

Besides the MBS materials, related terpolymers have been prepared. These include materials prepared by terpolymerising methyl methacrylate, acrylonitrile and styrene in the presence of polybutadiene (Toyolac, Hamano 500) methyl methacrylate, acrylonitrile and styrene in the presence of a butadiene-methyl methacrylate copolymer (XT Resin), and methylacrylate, styrene and acrylonitrile on to a butadiene-styrene copolymer. 

Neoprene AH (1975). It is a methylacrylate-modified elastomer which is non-crystallizing and is chemically peptizable in aliphatic solvents. However, it is generally prepared as a dispersion in hexane, and has balanced properties between conventional solvent-borne adhesives and aqueous systems. 

Chemical Designations - Synonyms Methacrylate monomer Methacrylic acid, methyl ester Methyl alpha-methylacrylate Methyl 2-methyl-2-propenoate Chemical Formula CHj=C(CH3)COOCHj Observable Characteristics - Physical State (as shipped) Liquid Color Colorless Odor Sharp, fragrant pleasant smelling pungent ester. 

Beaded methacrylate polymers, poly(hydroxyethylmethacrylate), Spheron, Separon (29), and poly(glycidylmethacrylate), Eupergin (30,31), are studied extensively at the Czechoslovak Academy of Macromolecular Sciences. An addition to this type of support is poly(oxyethylene-dimethacrylate) (32). Heitz et al. (33) described the preparation of beaded poly(methylacrylates) cross-linked with ethanedimethacrylates. 

Chiral dihydropyridines such as 103 were also accessible from Zincke-derived N-alkyl pyridinium salt 102 (Scheme 8.4.34). The dihydropyridine underwent cycloaddition with methylacrylate, providing chiral isoquinuclidine derivative 104 as the major diastereomeric product. ... 

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). 

Various o-quinodimethanes, generated in situ from o-alkenylbenzyltributyl-stannane precursors, have been used to synthesize functionalized polycycles by Diels Alder reaction with maleic anhydride, methylacrylate, dimethylfumarate and N-phenyl maleimide in the presence of electrophiles [37] (Scheme 2.16). 

Sulfinyldiene 40 reacts, regio- and stereo selectively, with methylacrylate in the presence of a catalyst, affording carbomethoxycyclohexene derivatives [45]. Among the catalysts examined, the best was lithium perchlorate used as a suspension in DCM it gave only endo isomers in 70% yield in a 96 4 d.e. ratio (Equation 3.11). 

In contrast, modest enantioselection has been observed in the asymmetric Diels-Alder reaction between cyclopentadiene (18) with methylacrylate and methylpropiolate catalyzed by chiral organoaluminum reagents 58 [59] (Equation 3.15) prepared from trimethylaluminum and (R)-(+)-3,3 -bis(triphenylsi-lyl)-l,l -bi-2-naphthol [60]. The reaction was highly cnJo-diastereoselective. 

A marked dependence of the reaction yield on the nature of the Lewis-acid catalyst and on the diene-dienophile ratio was observed (Table 5.4). 2-Pyrone (165) reacted at 18.5 kbar with methylacrylate but the reaction was unregiose-lective and undiastereoselective. 

Addition of CBr4 to a number of monomers including functional-substituted monomers (heptene-1, octene-1, styrene, and methylacrylate) has been performed in the presence of SmJ2 under mild conditions to give the adducts in high yield (ref. 4). 

PAMAM dendrimers are synthesized in a multistep process. Starting from a multifunctional amine (for example ammonia, ethylenediamine, or tris(2-amino-ethyl)amine) repeated Michael addition of methylacrylate and reaction of the product with ethylenediamine leads to dendrimers of different generation numbers [1,9]. Two methylacrylate monomers are added to each bifunctional ethylenediamine generating a branch at each cycle. Unreacted ethylenediamine has to be completely removed at each step to prevent the initiation of additional dendrimers of lower generation number. Excess methylacrylate has also to be removed. Bridging between two branches of the same or of two different dendrimers by ethylenediamine can also be a problem, and has to be avoided by choosing appropriate reaction conditions. 

Two different emulsion polymerization reactions were Investigated. One was the polymerization of acrylonitrile and methylacrylate (75/25 AN/MA) In the presence of an acrylonitrile elastomer (70/30 BD/AN) to produce a graft resin, llie second was the copolymerization oiE acrylonitrile and styrene (70/30 AN/S). Chromatographic analyses of latex solutions were conducted periodically during both types of polymerization reactions, using acetonitrile as latex solvent and chromatographic mobile phase. 

Unreacted monomers In AN/M latex solutions were measured similarly. Methylacrylate Is a relatively strong UV absorber In the 225-250 nm range while acrylonitrile does not significantly absorb UV radiation at wavelengths above about 220 nm. At 230 nm, the wavelength used, the UV detector responded only to methylacrylate. And the refractive Indices of the two monomers are such that. In the 75/25 AN/MA proportions used, the refrac-tometer was Insensitive to methylacrylate. The reiErac tome ter therefore functioned as a selective detector for acrylonitrile In the presence of methylacrylate. 

Similarly, estimation of chemical composition of soluble polymer was also dependent on selectivity of the UV detector. Polymerized acrylonitrile has no significant UV absorbance at 230 and 254 nm. Thus, UV chromatograms were used to estimate amounts of polymerized methylacrylate and styrene In each resin system. The refractometer detector was sensitive to polymerized methylacrylate and styrene, as well as to polymerized acrylonitrile. It was therefore necessary to calculate comonomer contribution to refractometer peak areas In order to estimate concentration of polymerized acrylonitrile. This was done by obtaining a refractometer calibration for all three homopolymers. Quantity of polymerized comonomers measured by UV were then converted to equivalent refractometer peak areas. Peak areas due to polymerized acrylonitrile were then calculated by difference, and used to calculate amount of polymerized acrylonitrile. 

All three monomers were soluble In the chromatographic mobile phase and standard analytical techniques were used for calibration. Solutions containing known quantities of monomer were chromatographed to establish a peak area concentration relationship for the appropriate detector. The homopolymer of methylacrylate was also soluble In the mobile phase. Thus, both UV and refractometer detectors were calibrated for polymerized methylmethacrylate by chromatographing solutions of PM ... 

Calculated monomer proportions In solubilized copolymer at each conversion level are compared to unreacted monomer proportions in Table I. At low conversion levels, T3-T5, the copolymer appeared to be rich In methylacrylate. This anomaly was not detected In unreacted monomer measurements, possibly because the amount of copolymer was small relative to the large excess of unreacted monomers. As conversion Increased (T5-Tj 4> calculated copolymer composition approached the 75/25 AN/MA target and averaged exactly 75/25. 

In attempted hydroalkoxylations of methylacrylate with ethanol catalysed by the copper ethoxides 100 or 102, copper-catalysed transesterification to the ethylacrylate was observed instead of the addition reaction [81]. 

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