Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Acrylic acid preparation

Fig. 14. Hyperbranched polymer grafts prepared on a mercaptoundecanoic acid (MUA) self assembled monolayer confined to a gold substrate. PAAM-c-PAA represents a random copolymer of poly(acrylamide) and poly(acrylic acid) prepared from the poly(acrylic acid) carboxylic acid groups and an amine [129]... Fig. 14. Hyperbranched polymer grafts prepared on a mercaptoundecanoic acid (MUA) self assembled monolayer confined to a gold substrate. PAAM-c-PAA represents a random copolymer of poly(acrylamide) and poly(acrylic acid) prepared from the poly(acrylic acid) carboxylic acid groups and an amine [129]...
Said, H. M., AUa, S. G. A., and El-Naggar, A. W. M. Synthesis and characterization of novel gels based on carboxymethyl ceUulose/acrylic acid prepared by electron beam irradiation. React. Funct. Polym. 61 (2004) 397-404. [Pg.296]

Precise dosage of reactive components is essential for the reproducible hardening of dental cements, without adversely affecting the physical properties of the hardened product. Cellulose acetate butyrate microcapsules containing poly(acrylic acid) prepared by phase separahon when mixed with glass ionomer powder result in single-phase, free-flowing powders [64]. The contents of microcapsules can be released and become mixed with the solid phase by mechanical stress, vibration microwaves, and/or sonicahon. [Pg.178]

Muller M, Kessler B, Frohlich J, Poeschla S, Torger B (2011) Polyelectrolyte complex nanoparticles of poly(ethyleneinine) and poly(acrylic acid) preparation and applications. [Pg.62]

CHi=CMeCOOH. Colourless prisms m.p. 15-16 C, b.p. 160-5 C. Manufactured by treating propanone cyanohydrin with dilute sulphuric acid. Polymerizes when distilled or when heated with hydrochloric acid under pressure, see acrylic acid polymers. Used in the preparation of synthetic acrylate resins the methyl and ethyl esters form important glass-like polymers. [Pg.258]

CHjlCH COOH. Colourless liquid having an odour resembling that of ethanoic acid m.p. 13 C, b.p. I4I°C. Prepared by oxidizing propenal with moist AgO or treating -hy-droxypropionitrile with sulphuric acid. Slowly converted to a resin at ordinary temperatures. Important glass-like resins are now manufactured from methyl acrylate, see acrylic resins. Propenoic acid itself can also be polymerized to important polymers - see acrylic acid polymers. [Pg.329]

Asymmetric hydrogenation has been achieved with dissolved Wilkinson type catalysts (A. J. Birch, 1976 D. Valentine, Jr., 1978 H.B. Kagan, 1978). The (R)- and (S)-[l,l -binaph-thalene]-2,2 -diylblsCdiphenylphosphine] (= binap ) complexes of ruthenium (A. Miyashita, 1980) and rhodium (A. Miyashita, 1984 R. Noyori, 1987) have been prepared as pure atrop-isomers and used for the stereoselective Noyori hydrogenation of a-(acylamino) acrylic acids and, more significantly, -keto carboxylic esters. In the latter reaction enantiomeric excesses of more than 99% are often achieved (see also M. Nakatsuka, 1990, p. 5586). [Pg.102]

The key step in the total synthesis of rhizobitoxine is the Pd-catalyzed exchange reaction of the methyl alkenyl ether moiety in 4 with the functionalized alcohol, although the yield is low[3]. The enol pyruvate 6 (a-ethoxyacrylic acid) is prepared by the reaction of methyl a-methoxyacrylate or a-methoxy-acrylic acid (5) with ethanol catalyzed by PdCl2(PhCN)2 at room temperature in the presence of CuCli and NaH2P04[4],... [Pg.529]

Since the exocyclic sulfur is more reactive in the ambident anion than in A-4-thiazoIine-2-thione. greater nucleophilic reactivity is to be expected. Thus a large variety of thioethers were prepared in good yields starting from alkylhalides (e.g.. Scheme 38 (54, 91, 111, 166-179). lactones (54, 160), aryl halides (54, 152. 180, 181), acyl chlorides (54. 149, 182-184). halothiazoles (54, 185-190), a-haloesters (149. 152. 177. 191-194), cyanuric chloride (151). fV.N-dimethylthiocarbamoyl chloride (151, 152. 195. 196), /3-chloroethyl ester of acrylic acid (197), (3-dimethylaminoethyl chloride (152). l,4-dichloro-2-butyne (152), 1,4-dichloro-2-butene (152), and 2-chloro-propionitrile (152). A general... [Pg.396]

Poly(acrylic acid) and Poly(methacrylic acid). Poly(acryHc acid) (8) (PAA) may be prepared by polymerization of the monomer with conventional free-radical initiators using the monomer either undiluted (36) (with cross-linker for superadsorber appHcations) or in aqueous solution. Photochemical polymerization (sensitized by benzoin) of methyl acrylate in ethanol solution at —78° C provides a syndiotactic form (37) that can be hydrolyzed to syndiotactic PAA. From academic studies, alkaline hydrolysis of the methyl ester requires a lower time than acid hydrolysis of the polymeric ester, and can lead to oxidative degradation of the polymer (38). Po1y(meth acrylic acid) (PMAA) (9) is prepared only by the direct polymerization of the acid monomer it is not readily obtained by the hydrolysis of methyl methacrylate. [Pg.317]

Acrylic Acid, Acrylates, and Acrylonitrile. Acryhc acid [79-10-7], and acrylates were once prepared by reaction of acetylene and... [Pg.102]

Hydroxyethyi and 2-hydroxypropyl acrylates are prepared by the addition of ethylene oxide or propylene oxide to acryhc acid (104,105). [Pg.156]

Historically, the development of the acrylates proceeded slowly they first received serious attention from Otto Rohm. AcryUc acid (propenoic acid) was first prepared by the air oxidation of acrolein in 1843 (1,2). Methyl and ethyl acrylate were prepared in 1873, but were not observed to polymerize at that time (3). In 1880 poly(methyl acrylate) was reported by G. W. A. Kahlbaum, who noted that on dry distillation up to 320°C the polymer did not depolymerize (4). Rohm observed the remarkable properties of acryUc polymers while preparing for his doctoral dissertation in 1901 however, a quarter of a century elapsed before he was able to translate his observations into commercial reaUty. He obtained a U.S. patent on the sulfur vulcanization of acrylates in 1912 (5). Based on the continuing work in Rohm s laboratory, the first limited production of acrylates began in 1927 by the Rohm and Haas Company in Darmstadt, Germany (6). Use of this class of compounds has grown from that time to a total U.S. consumption in 1989 of approximately 400,000 metric tons. Total worldwide consumption is probably twice that. [Pg.162]

In paints, zinc oxide serves as a mildewstat and acid buffer as well as a pigment. The oxide also is a starting material for many zinc chemicals. The oxide supphes zinc in animal feeds and is a fertilizer supplement used in zinc-deficient soils. Its chemical action in cosmetics (qv) and dmgs is varied and complex but, based upon its fungicidal activity, it promotes wound healing. It is also essential in nutrition. Zinc oxide is used to prepare dental cements in combination with eugenol and phosphoric and poly(acrylic acid)s (48) (see Dental materials). [Pg.423]

This azlactone is prepared readily from benzaldehyde according to the procedure given for the azlactone of a-ben-zoylamino-/3-(3,4-dimethoxyphenyl)-acrylic acid (Org. Syn. 13, 8). From 53 g. (0.5 mole) of benzaldehyde, 89.5 g. (0.5 mole) of hippuric acid, 41 g. of fused sodium acetate, and 153 g. of acetic anhydride there is obtained 78-80 g. (62-64 per cent yield) of an almost pure product melting at 165-166° (corr.). This material is sufficiently pure for use in the preparation of phenylalanine. By crystallization from 150 cc. of benzene a product melting at 167-168° (corr.) is obtained. [Pg.81]

In September 1964 the Du Pont company announced materials that had characteristics of both thermoplastics and thermosetting materials. These materials, known as ionomers, are prepared by copolymerising ethylene with a small amount (1-10 % in the basic patent) of an unsaturated carboxylic acid such as acrylic acid using the high-pressure process. Such copolymers are then treated... [Pg.277]

Several selective interactions by MIP membrane systems have been reported. For example, an L-phenylalanine imprinted membrane prepared by in-situ crosslinking polymerization showed different fluxes for various amino acids [44]. Yoshikawa et al. [51] have prepared molecular imprinted membranes from a membrane material which bears a tetrapeptide residue (DIDE resin (7)), using the dry phase inversion procedure. It was found that a membrane which contains an oligopeptide residue from an L-amino acid and is imprinted with an L-amino acid derivative, recognizes the L-isomer in preference to the corresponding D-isomer, and vice versa. Exceptional difference in sorption selectivity between theophylline and caffeine was observed for poly(acrylonitrile-co-acrylic acid) blend membranes prepared by the wet phase inversion technique [53]. [Pg.136]

The polymers were prepared using MAA as functional monomer and EDMA as crosslinking monomer if not otherwise noted. VPY= 2- or 4-vinylpyridine TRIM = trimethylolpropane trimethacrylate DPGE = (R)-N,0-dimethacryloylphenylglycinol PYAA = 3-(4-pyridinyl)acrylic acid. [Pg.156]

In a partially crystalline homopolymer, nylon 6, property enhancement has been achieved by blending with a poly(ethylene-co-acrylic acid) or its salt form ionomer [24]. Both additives proved to be effective impact modifiers for nylon 6. For the blends of the acid copolymer with nylon 6, maximum impact performance was obtained by addition of about 10 wt% of the modifier and the impact strength was further enhanced by increasing the acrylic acid content from 3.5 to 6%. However, blends prepared using the salt form ionomer (Sur-lyn 9950-Zn salt) instead of the acid, led to the highest impact strength, with the least reduction in tensile... [Pg.151]

The main use of acrolein is to produce acrylic acid and its esters. Acrolein is also an intermediate in the synthesis of pharmaceuticals and herhicides. It may also he used to produce glycerol hy reaction with isopropanol (discussed later in this chapter). 2-Hexanedial, which could he a precursor for adipic acid and hexamethylene-diamine, may he prepared from acrolein Tail to tail dimenization of acrolein using ruthenium catalyst produces trans-2-hexanedial. The trimer, trans-6-hydroxy-5-formyl-2,7-octadienal is coproduced. Acrolein, may also he a precursor for 1,3-propanediol. Hydrolysis of acrolein produces 3-hydroxypropionalde-hyde which could he hydrogenated to 1,3-propanediol. ... [Pg.217]

Morishima et al. [42] prepared polyanions (A-x, 3) of various charge densities tagged with the merocyanine dye (Me) by terpolymerization of acrylic acid (AA), acrylamide (AAm), and a small mole fraction of l-(2-methacryloyloxyethyl)-4-(2-(4-hydroxyphenyl)ethenyl)pyridinium bromide (MA-Mc). Since these polyanions carry only 1 mol% of the MA-Mc units, they can practically be treated as copolymers of AA and AAm with a wide range of composition. [Pg.57]

Thomas et al. [64] prepared copolymers of 1-pyreneacrylic acid with acrylic acid (AA), 17, and with methacrylic acid (MA), 18, incorporating not more than one pyrene unit per polymer chain. The mole ratios of pyrene to AA and MA units were 1150 and 1390, respectively. The molecular weights of 17 and 18 were 8.3 x lO4... [Pg.73]

So far, many kinds of nucleophiles active for hydrolysis such as imidazolyl-, amino-, pyridino-, carboxyl- and thiol-groups, have been used for preparation of hydrolase models. Overberger et al.108,1091 prepared copolymers of vinylimidazole and acrylic acid 60 (PVIm AA), by which the cationic substrate, 61 (ANTI), was hydrolyzed. This kind of copolymer is considered to be a model of acetylcholinesterase. With ANTI, the rate of the copolymer catalysis was higher than that of imidazole itself in the higher values of pH, as is seen in Table 9. In this work, important contributions of the electrostatic interactions are clear. The activity of the copolymer was not as high with the negatively charged and neutral substrates. [Pg.162]

A modified latex composition contains a phosphorus surface group. Such a latex is formed by emulsion polymerization of unsaturated synthetic monomers in the presence of a phosponate or a phosphate which is intimately bound to the surface of the latex. Thus, a modified latex containing 46% solids was prepared by emulsion polymerization of butadiene, styrene, acrylic acid-styrene seed latex, and a phosphonate comonomer in H20 in the presence of phosphated alkylphenol ethoxylate at 90°C. The modified latex is useful as a coating for substrates and as a binder in aqueous systems containing inorganic fillers employed in paper coatings, carpet backings, and wallboards [119]. [Pg.602]


See other pages where Acrylic acid preparation is mentioned: [Pg.218]    [Pg.231]    [Pg.13]    [Pg.218]    [Pg.231]    [Pg.13]    [Pg.316]    [Pg.143]    [Pg.470]    [Pg.254]    [Pg.192]    [Pg.339]    [Pg.558]    [Pg.459]    [Pg.95]    [Pg.142]    [Pg.69]    [Pg.207]    [Pg.216]    [Pg.218]    [Pg.482]    [Pg.494]    [Pg.124]    [Pg.938]    [Pg.160]   
See also in sourсe #XX -- [ Pg.854 ]




SEARCH



Acrylates preparation

Acrylic acid Catalyst preparation

Acrylic acid fiber preparation

Acrylic acid, 3- -, ethyl ester, preparation

Preparation of Acid Functional Acrylic Resin

Preparation of an Acrylate Copolymer Latex Containing Acidic Groups

© 2024 chempedia.info