Polymethyl acrylate properties

The mechanical properties of blends and graft polymers are determined primarily by the mutual solubility of the two homopolymers. For complete solubility, the properties of the mixture are close to those of a random copolymer of the same composition, as is shown in Figure 10.4, which compares a 50 50 mixture of polyvinyl acetate and polymethyl acrylate with the equivalent copolymer [15]. Note that the damping peak occurs at 30°C, compared with 15°C for the polymethyl acrylate and 45°C for polyvinyl acetate. 

Uses Defbamer for latex paints, latex-based stucco finishes, latex-based adhesives based on polymethyl acrylate, vinyl ester, and styrene copolymers Properties Wh. liq. si. odor hydrocarbon-like odor immisc. with water sp.gr. 0.93 g/cc dens. 7.73 Ib/gal kinematic vise. > 300.0 mm /s vapor pressure 18 mm Hg flash pt. (Seta) > 110 C 53% NV in water/oil Toxicology LD50 (oral, rat) >20000 mg/kg skin and eye irritant, high cones, may irritate respiratory tract TSCA listed... 

Acrylic is a generic name for derivatives of acrylic acid, of which methyl methacrylate is the most important. Polymerization is controlled to produce chain length of 800 to 3,000 monomer units. A small amount of plasticizer such as dibutyl phthalate may be added before bulk polymerization to assist in deep molding. The outstanding property of polymethyl metliacrylate is 0 transparency resistance to ultraviolet radiation from fluorescent lamps and ability to be... 

Methyl methacrylate is only one of a family of monomers, including the various esters of acrylic, methacrylic, and ethacrylic acids, which are polymerized to produce the thermoplastic resins known as the acrylates. A wide variety of reactions and starting materials may be utilized for their production however, the principal commercial product is polymethyl methacrylate, sold by Du Pont and Rohm Haas under the trade names of Lucite and Plexiglas, respectively. These materials were introduced to the United States market in 1936 (44) and have received widespread acceptance due principally to their outstanding optical properties. Production in 1949 was reported as about 22,000,000 to 25,000,000 pounds and peak wartime capacity was above30,000,000 pounds. While this can account for only about 2% of the current production of propylene for chemical purposes, the acrylate resins are of considerable commercial importance as they are sold at a relatively high price and are the only materials available that will meet the requirements for certain military and civilian products. 

Acrylic. Acrylic resins (polymethyl methacrylate) have exceptional optical clarity and good weather resistance, strength, electrical properties, and chemical resistance. They have low water absorption characteristics. However, acrylics are attacked by strong solvents, gasoline, acetone, and similar organic fluids. 

The acrylic plastics use the term acryl such as polymethyl methacrylate (PMMA), polyacrylic acid, polymethacrytic acid, poly-R acrylate, poly-R methacrylate, polymethylacrylate, polyethylmethacrylate, and cyanoacrylate plastics. PMMA is the major and most important homopolymer in the series of acrylics with a sufficient high glass transition temperature to form useful products. Repeat units of the other types are used. Ethylacrylate repeat units form the major component in acrylate rubbers. PMMAs have high optical clarity, excellent weatherability, very broad color range, and hardest surface of any untreated thermoplastic. Chemical, thermal and impact properties are good to fair. Acrylics will fail in a brittle manner, independent of the temperature. They will suffer crazing when loaded at stress about halfway to the failure level. This effect is enhanced by the presence of solvents. 

Literature continues to be rather extensive on this subject since the 1930s. A summarization is provided in this section. Products fabricated include sheets, films, rods and tubes, and embedment. Acrylic castings usually consist of polymethyl methacrylate (PMMA) or copolymers of this ester as the major component with small amounts of other monomers to modify the properties (Chapter 2). Adding acrylates or higher methacrylates lowers the heat deflection temperature and hardness and improves thermoformability and solvent cementing capability, with some loss in resistance to weathering. Dimethacrylates or other crosslinking monomers increase the resistance to solvents and moisture. 

Alkyl a-acetoxyacrylate intermediates were prepared by condensing pyruvate derivatives with acetic anhydride and then free radically converting them into the corresponding homo- or copolymers. All copolymers had thermal properties that were superior to that of polymethyl methacrylate. In addition poly(ethyl a-acetoxy-acrylate) homopolymers were injection moldable at 250°C. 

Contact lenses are the most common polymer product in ophthalmology. The basic requirements for this type of materials are (T)excellent optical properties with a refractive index similar to cornea good wettability and oxygen permeability ( ) biologically inert, degradation resistant and not chemically reactive to the transfer area ( ) with certain mechanical strength for intensive processing and stain and precipitation prevention. The common used contact lens material includes poly-P-hydroxy ethyl methacrylate, poly-P-hydroxy ethyl methacrylate-N-vinyl pyrrolidone, poly-P-hydroxy ethyl methacrylate, Poly-P-hydroxy ethyl methacrylate - methyl amyl acrylate and polymethyl methacrylate ester-N-vinyl pyrrolidone, etc. The artificial cornea can be prepared by silicon rubber, poly methyl... 

Uses Flame retardant, plasticizer for PVC and copolymers, PVC plasti-sols, PVC textile coatings, PVAc, cellulosics, polymethyl methacrylate, PS, PP, engineering resins, unsat. polyester, alloys, clear films and sheets. Buna N rubber, acrylic, phenolics food-contact applies. Features Low smoke generation exc. low temp, props. improves processing due to exc. resin solvating power Reguiatory FDA approved for food contact use Properties Colorless clear liq. essentially odorless sol. in most org. soivs. m.w. 362 sp.gr. 1.090 (20/20 C) dens. 9.1 Ib/gal vise. 18 mPas vapor pressure 0.2 mm Hg (150 C) b.p. 462 F (10 mm, dec.) pour pt. -65.2 F flash pt. (COC) 435 F fire pt. (COC) 460 F ref. index 1.508-1.511 8.5% P Phosflex 390 [Akzo Nobel Hatwick Std. Distrib.]... 

The acrylic polymer which offers the best all-round properties for a metal-coating lacquer exposed to the weather, is the hardest acrylic polymer, polymethyl methacrylate (molecular weight 80 000-150 000). It is hard, clear, scarcely coloured, very little affected by ultra-violet light, insoluble in commercial petrols and resistant to acids and alkalis. Marked deviations from the homopolymer reduce one or... 

This technique has found the following applications in addition to those discussed in Sections 10.1 (resin cure studies on phenol urethane compositions) [65], 12.2 (photopolymer studies [66-68]), and 13.3 (phase transitions in PE) [66], Chapter 15 (viscoelastic and rheological properties), and Section 16.4 (heat deflection temperatures) epoxy resin-amine system [67], cured acrylate-terminated unsaturated copolymers [68], PE and PP foam [69], ethylene-propylene-diene terpolymers [70], natural rubbers [71, 72], polyester-based clear coat resins [73], polyvinyl esters and unsaturated polyester resins [74], polyimide-clay nanocomposites [75], polyether sulfone-styrene-acrylonitrile, PS-polymethyl methacrylate (PMMA) blends and PS-polytetrafluoroethylene PMMA copolymers [76], cyanate ester resin-carbon fibre composites [77], polycyanate epoxy resins [78], and styrenic copolymers [79]. 

Bulk Polymerization The polymerization of a monomer (mass polymerization) in the absence of any medium other than a catalyst or accelerator. The monomer is usually a liquid, but the term also applies to the polymerization of glass and solids in the absence of solvents or any other dispersing medium. Polystyrene, polymethyl methacrylate, low-density polyethylene, and styrene-acrylonitrile copolymers are examples of polymers most frequently produced by bulk polymerization. Acrylic monomers may be simultaneously polymerized and formed into products by conducting the polymerization in molds such as those for rods and sheets. (Odian GC, (2004) Principles of polymerization, Wiley, New York Mark JE (ed) (1996) Physical properties of polymers handbook. Springer, New York)... 

Castor oil has found application in the synthesis of interpenetrating polymer networks (IPNs). These materials can be defined as a combination of two polymer networks, at least one of which is synthesized and/or cross-linked in the immediate presence of the other. They are called semi-lPN if just one of the polymers is a network (Athawale et al, 2003). Early reports on castor oil IPNs appeared in 1977 by Yenwo and co-workers. The report discussed the synthesis possibilities via cross-linking of double bonds with sulfur, reaction of hydroxyl groups with diisocyanates, and emulsion polymerizations with saponified ricinoleic acids as emulsifier. Moreover, the IPNs from acrylic polymers, such as polymethyl methacrylate and poly-2-ethoxyethyl methacrylate, and castor oil-based polyurethanes were reported to contribute to the final properties of the material (Cunha et al., 2004 Sanmathi et al, 2004). Incorporation of acrylic moieties into the PU networks increased toughness and thermal properties. In contrast, IPN polyesters derived from castor oil and dibasic acids (e.g. malonic, succinic, glutaric, adipic, suberic, and sebacic acid) were obtained as soft and opaque elastomers (Suthar et al, 2003). 

PMMA (Acrylic, also known as Perspex) - is often used for its optical properties. Polymethyl methacrylate absorbs very little incident light, infact the light transmission through a parallel sheet free from faults is about 92%. The mar resistance of acrylic polymers is poor and is often upgraded through the use of a clear hardcoat... 

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