Methacrylic resins

Specimens for (S)TEM have to be transparent to the electron beam. In order to get good contrast and resolution, they have to be thin enough to minimize inelastic scattering. The required thin sections of organic materials can be obtained by ultramicrotomy eitlier after embedding into suitable resms (mostly epoxy- or methacrylate resins [H]) or directly at low temperatures by cryo-ultramicrotomy [12]. 

Hydroxy-2-methylpropanenitrile is then reacted with methanol (or other alcohol) to yield methacrylate ester. Free-radical polymerization is initiated by peroxide or azo catalysts and produce poly(methyl methacrylate) resins having the following formula ... 

Acrylate or methacrylate resins (R = H or CH ) have been obtained from l-3-bis(hexa uoroisopropanolyl)-4- uoroalkylbenzene (144), where... 

The principal U.S. market for methacrylate resins is for glazing and skylights. Other significant markets include consumer products, transportation signs and lighting fixtures, plumbing (spas, tubs, showers, sinks, etc), and panels and siding (106,107). 

The addition—reaction product of bisphenol A [80-05-07] and glycidyl methacrylate [106-91-2] is a compromise between epoxy and methacrylate resins (245). This BSI—GMA resin polymerizes through a free-radical induced covalent bonding of methacrylate rather than the epoxide reaction of epoxy resins (246). Mineral fillers coated with a silane coupling agent, which bond the powdered inorganic fillers chemically to the resin matrix, are incorporated into BSI—GMA monomer diluted with other methacrylate monomers to make it less viscous (245). A second monomer commonly used to make composites is urethane dimethacrylate [69766-88-7]. 

While the control resins were deep red in color due to the presence of soluble porphyrin complexes, the methacrylate resins obtained after removal of the polyethylene-supported catalysts varied from light yellow to nearly water-white (APHA < 25). UV-Vis spectrophotometric analysis of the yellow resins indicated an absorption signal for the cobalt porphyrin complex Soret band (wavelength of cobalt(ll) porphyrin species appears at -415 nm free porphyrin ligand is formd at -423 tun). Resin samples that visttally appear as water-white show little or no porphyrin species present in the spectrum. Measured catalyst activity and PDl of the polyethylene-supported porphyrin complexes are in the expected range for soluble porphyrin CCT catalysts (PDl = M /Mn - 1.2- 2.0)." The screening resrrlts clearly... 

The most well-developed recent examples of catalysis concern catalysts for oxidation reactions these are essentially achiral or chiral metal-salen complexes. Taking into account a number of results suggesting the importance of a degree of mobility of the bound complex, Sherrington et al. synthesized a series of polymer-supported complexes in which [Mn(salen)Cl] units are immobilized in a pendant fashion by only one of the aromatic rings, to polystyrene or poly(methacrylate) resin beads of various morphology (Figure 6).78,79... 

In this work we have demonstrated that a new class of heavily fluorinated acrylic and methacrylic resins can be efficiently synthesized and then cured to solid form with radical initiator at elevated temperatures. These cured resins were found to have low dielectric constants, which are close to the minimum known values for Teflon and Teflon AF. In contrast to tetrafluoroethylene, our monomers are processable owing to the fact that they are liquids or low-melting solids, and moreover are soluble in common organic solvents. Lower dielectric constants are obtained as fluorine contents on the polymer backbone or side chain increase, when acrylate is replaced by methacrylate, when ether linkages are present in the fluorocarbon, and when aromatic structure is symmetrically meta-substituted. 

VDC copolymer with, 25 707 world production capacity of, 76 255t Methyl methacrylate resins, manufacture of, 19 50... 

Methacrylate resins are produced from monomeric methacrylic acid methyl ester, a markedly lower temperature being employed in their polymerization. The heat resistance of the pigments is therefore only of minor importance in this medium. 

Unsaturated polyester and methacrylate resins are frequently colored with pigment-plasticizer (DIDP) pastes. They have no measurable adverse effect on the important mechanical properties of the finished article. To a small extent pigments are also dispersed directly in one part of the monomer. 

Itaconic Acid. Structurally an a-substituted methacrylic acid, itaconic acid constitutes a C5 building block with significant market opportunities. It is currently produced via fungal fermentation at about 10,000 t/a and mainly used as a specialty comonomer in acrylic or methacrylic resins, as incorporation of small amounts of itaconic acid into polyacrylonitrile significantly improve their dyeability. 

Uses Manufacturing methacrylate resins and plastics (e.g., Plexiglas and Lucite) impregnation of concrete. 

Plexigum Acrylate and methacrylate resins Rohm Haas... 

Hydrogen cyanide in pure form was prepared first in 1815 by Gay-Lussac. Earher, in 1782, Scheel prepared this compound in dilute solution. The most important apphcation of hydrogen cyanide is to produce methyl methacrylate for methacrylate resins and plastics. Other products made from hydrogen cyanide include potassium cyanide, sodium cyanide, adiponitrile, methionine, cyanuric chloride, cyanogen, nitrilotriacetic acid, and several triazine pesticides. The compound also is used in small amounts for extermination of rodents. 

When convective heating is used it is important to localize the heating channels on an appropriate distance from the tool surface. The part can be damaged by print-through if the distance between the surface and the channels is too small. The surface temperature may vary and give rise to unacceptable cure variations if the distance is too large. As a rule of thumb the distance to the surface in mass cast tools from aluminum-filled methacrylic resin should be... 

In the case of amorphous intermediate 4, the weakly acidic cation exchange resin DIAION WKIOO was selected as the CEC stationary phase. The resin comprises a methacrylate resin matrix and carboxylic acid, which functions as an exchange group with a high ion exchange rate. Figure 9.4 illustrates the concept behind the CEC procedure for 4 ... 

PVDF is among the few semicrystalline polymers that exhibit thermodynamic compatibility with other polymers,80 in particular with acrylic or methacrylic resins.81 The morphology, properties, and performance of these blends depend on the structure and composition of the additive polymer, as well as on the particular PVDF resin. These aspects have been studied and are reported in some detail in Reference 82. For example, polyethyl acrylate is miscible with polyvinylidene fluoride, but polyisopropyl acrylate and homologues are not. Strong dipolar interactions are important to achieve miscibility with PVDF, as suggested by the observation that polyvinyl fluoride is incompatible with polyvinylidene fluoride.83... 

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