Acryhc monomer

Acryhc acid and esters are stabilized with minimum amounts of inhibitors consistent with stabihty and safety. The acryhc monomers must be stable and there should be no polymer formation for prolonged periods with normal storage and shipping (4,106). The monomethyl ether of hydroquinone (MEHQ) is frequentiy used as inhibitor and low inhibitor grades of the acrylate monomers are available for bulk handling. MEHQ at 10—15 ppm is generally... 

The toxicity of common acryhc monomers has been characterized in animal studies using a variety of exposure routes. Toxicity varies with level, frequency, duration, and route of exposure. The simple higher esters of acryhc acid are usually less absorbed and less toxic than lower esters. In general, acrylates are more toxic than methacrylates. Data appear in Table 5. 

With respect to acute toxicity, based on lethaHty in rats or rabbits, acryhc monomers are slightly to moderately toxic. Mucous membranes of the eyes, nose, throat, and gastrointestinal tract are particularly sensitive to irritation. Acrylates can produce a range of eye and skin irritations from slight to corrosive depending on the monomer. 

Full eye protection should be worn whenever handling acryhc monomers contact lenses must never be worn. Prolonged exposure to Hquid or vapor can result in permanent eye damage or blindness. Excessive exposure to vapors causes nose and throat irritation, headaches, nausea, vomiting, and dizziness or drowsiness (solvent narcosis). Overexposure may cause central nervous system depression. Both proper respiratory protection and good ventilation are necessary wherever the possibiHty of high vapor concentration arises. 

Swallowing acryhc monomers may produce severe irritation of the mouth, throat, esophagus, and stomach, and cause discomfort, vomiting, diarrhea, dizziness, and possible coUapse. 

Repeated exposures to acryhc monomers can produce allergic dermatitis (or skin sensitization) resulting in rash, itching, or sweUing. After exposure to one monomer, this dermatitis may arise upon subsequent exposure to the same or even a different acryhc monomer. 

The surfactants used in the emulsion polymerization of acryhc monomers are classified as anionic, cationic, or nonionic. Anionic surfactants, such as salts of alkyl sulfates and alkylarene sulfates and phosphates, or nonionic surfactants, such as alkyl or aryl polyoxyethylenes, are most common (87,98—101). Mixed anionic—nonionic surfactant systems are also widely utilized (102—105). 

Anaerobic stmctural adhesives are typically formulated from acryhc monomers such as methyl methacrylate [80-62-6] C Hg02, and methacrylic acid [79-41-4] (see Acrylic ester polymers). Very often, cross-linking agents such as dimethacrylates are also added. A peroxide, such as cumene... 

The principal monomer is acrylamide [79-06-17, where R = H and R = NH2, made by the hydrolysis of acrylonitrile. The homopolymer [9003-05-8] of acrylamide, which in theory has no electrical charge, has some use as a flocculant however, the majority of acrylamide-based flocculants are copolymers with acryHc monomers containing charged functional groups, such as those shown in Figure 1, or polymers containing functional groups formed by modification of acrylamide homopolymers or copolymers (Fig. 2). The chemistry of polyacrylamides has been reviewed by several authors (18—20) (see... 

Vinyl ethers can also be formulated with acryHc and unsaturated polyesters containing maleate or fumarate functionaHty. Because of their abiHty to form alternating copolymers by a free-radical polymeri2ation mechanism, such formulations can be cured using free-radical photoinitiators. With acryHc monomers and oligomers, a hybrid approach has been taken using both simultaneous cationic and free-radical initiation. A summary of these approaches can be found in Table 9. 

Calcium Chelates (Salicylates). Several successhil dental cements which use the formation of a calcium chelate system (96) were developed based on the reaction of calcium hydroxide [1305-62-0] and various phenohc esters of sahcyhc acid [69-72-7]. The calcium sahcylate [824-35-1] system offers certain advantages over the more widely used zinc oxide—eugenol system. These products are completely bland, antibacterial (97), facihtate the formation of reparative dentin, and do not retard the free-radical polymerization reaction of acryhc monomer systems. The principal deficiencies of this type of cement are its relatively high solubihty, relatively low strength, and low modulus. Less soluble and higher strength calcium-based cements based on dimer and trimer acid have been reported (82). 

Additions occur more easily if a carbanion with resonance or inductive stabilization is formed in the addition. Thus, fulvenes are very reactive, vinylsilanes and highly fluorinated alkenes somewhat less so. Styrene, 1,3-dienes, and enynes are more reactive than isolated alkenes, and Grignard reagents may be used to initiate anionic polymerization of styrenes, dienes, and acryhc monomers. Strained alkenes such as norbomenes and cyclopropenes are also more reactive. Examples of additions facilitated by resonance or substitution are shown in Scheme 8. 

Emulsion copolymerization of acryhc monomers and imconjugated dienes was studied with the aim to explore the possibihty to synthesize dispersions whose particles would contain reactive polymeric molectrles with free multiple C=C bonds. The usage of such latexes to Dnish fabrics and some other materials promotes getting strong indelible coatings. The kinetics and mechanism of emulsion copolymerization of EA and BA with allylacrylate (AlA) (with ammonimn persulfate (APS) or the APS—sodium thiosirlfate system as initiators) were studied. The foimd constants of copolymerization of AlA with EA (r",y = 1.05 = 0.8) and ALA with BA (r ... 

A promising technique for residual monomer removal is pervaporation, as no additional chemicals are needed for this membrane process and the energy costs are typically low. It has been shown that pervaporation can remove a considerable amount of acryhc monomer from polymethylmethacrylate (PMMA) latexes [15]. Apparently, the Hmiting factor for mass transfer does not occur in the polymer particles, mainly because of the high specific area of the polymer-water interface as compared to the membrane area. Although the high initial costs, as well as fouling of the membrane surface with the polymer particles, are potential drawbacks, pervaporation may thus be expected to provide a viable alternative. 

Many monofunctional monomers wiU not yield a three-dimensional network. Monomers with a functionality of two or more are often required for his purpose and attainment of desired properties in a coating. Among the many possible examples of a commercial difunctional acryhc monomer, is 1,4-butylene glycol diacrylate. It is prepared from 1,4-butanediol and can be illustrated as follows ... 

A number of acrylic resins are used for bonding cloth, plastics, leather, and, in some cases, metal foils. The acryhc monomers most commonly used in adhesives are ethyl acrylate, methyl acrylate, methacryhc acid, acrylic acid, acrylamide, and acrylonitrile. The polymers or copolymers are soluble in common organic solvents and can be supplied in much the same manner as other solvent-based systems. In addition, the polymers are soluble in the monomers. When a catalyst is added, monomers polymerize, thus providing good bonding to glass and to plastic surfaces of similar composition (e.g., polymethylmethacrylate). ... 

There are a wide variety of acryhc monomers available, each having specific properties. Styrene is often used as a comonomer in acrylic latexes because of its compatibility and wide availability. Auxiliary monomers can be used in small amounts to impart special properties to toe latex. Although acrylic monomers and styrene may be similar in reactivity, if toe monomer solubilities are significantly different, copolymerisation is less likely, possibly resulting in structured particle morphologies. The copolymer composition can be made more uniform by semi-continuous polymerisation. In some cases, a stmctured morphology is desired, and can be designed into toe process (225, 372). 

Number of grafted copolymers were prepared by the ozonization and grafting technique. Polyolefins, PE and PP, were grafted with fluorinated acrylates to obtain fluorine content between 11% and 25% that highly modified their properties. Likewise, PE and PVDF have been grafted with various acryhc monomers with the aim to improve their adhesive properties. From these products, it has been possible to attach composite materials, based on epoxy resins, to PE or PVDF. The main copolymers prepared according to this technique are summarized in Table 1. 

Wang ST, Schork FJ, Poehlein GW, Gooch JW. Emulsion and miniemulsion copolymerization of acryhc monomers in the presence of alkyd resin. J Appl Polym Sci 1996 60 2069-2076. 

It is used as a catalyst for the synthesis of acryhc monomers in plastic industries. 

Sogah, D.Y., Herder, W.R., Webster, O.W., and Cohen, G.M. (1987) Group-transfer polymerization. Polymerization of acryhc monomers. Macromolecules, 20,1473—1488. 

A DuPont de Nemours team working under O. Webster and D. Sogah discovered the group transfer polymerization of acryhc monomers and initiate various research works related to the controlled polymerization of these monomers. 

Functionality is introduced in several ways. Hydroxyl functionality is achieved either by partial hydrolysis of acetate groups in a PVC/VA polymer or by including a minor fraction of a hydroxyl-containing acryhc monomer, such as hydroxyethyl... 

ZUKOWSKA, G., WILLIAMS, J., STEVENS, J.R., et aZ.,The apphcation of acryhc monomers with acidic groups to the synthesis of proton-conducting polymer gels. Solid State Ionics, 2004,167,123-30. 

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