Of methacrylate polymers

Three bulk polymerization processes are commercially important for the production of methacrylate polymers batch cell casting, continuous casting, and continuous bulk polymerization. Approximately half the worldwide production of bulk polymerized methacrylates is in the form of molding and extmsion compounds, a quarter is in the form of cell cast sheets, and a quarter is in the form of continuous cast sheets. 

The molecular weight of a polymer can be controlled through the use of a chain-transfer agent, as well as by initiator concentration and type, monomer concentration, and solvent type and temperature (61). Chlorinated aUphatic compounds and thiols are particularly effective chain-transfer agents used for regulating the molecular weight of methacrylic polymers (see Table 10). 

A large number of methacrylate polymers have been prepared in addition to poly(methyl methacrylate). In many respects the properties of these materials are analogous to those of the polyolefins described in Chapter 8. 

Table 15.5 Vicat softening of methacrylate polymers from monomers of type CHj = C (CHj) COOR CO...

The mechanism of adhesion to various substrates has not been fully explained. Brauer Stansbury (1984b) consider that bonding to composite resins occurs by the diffusion of methacrylate polymer chains into the resin. Bonding to base metals is, perhaps, by salt or chelate bridges. Here it is significant that ZOE cements do not bond, so perhaps bonding is due to the action of free EBA on the substrate. The adhesion to porcelain is surprising. Porcelain is inert so that the attachment can hardly be chemical. Also, it would be expected that if a cement adheres to porcelain then it should adhere to untreated enamel and dentine, but this is not so. 

Table I Tendency of Methacrylate Polymers to Become Insoluble Samples on Aluminum Foil, Single-Carbon-Arc Fade-ometer (Corex D Filter), 62°C...

Feller, R. L., "Cross-Linking of Methacrylate Polymers by Ultraviolet Radiation", Preprints of papers presented at the New York Meeting, Division of Paint, Plastics and Printing Ink Chemistry, American Chemical Society, Sept., 1957, 17, No. 2, 465-470. 

Figure 5. SNMS depth profiles for a series of methacrylate polymer/Z6040 (<5 =9.3)/Al laminates. Profile a is fora laminate in which polyfisobutyl methacrylate) (d =8.65) was the polymer. Profiles b, c, and d utilized polyfethyl methacrylate) (<5 = 8.95), poly (methyl methacrylate) (i=9.3), and poly(benzyl methacrylate) (d = 9.9) as the polymer, respectively.

With a series of methacrylate polymers whose solubility parameters ranged from 8.65 to 9.9, it was shown that the polymer/silane interphase is influenced by the solubility parameters of the silane coupling agent and polymer. It was... 

Positive X ray Resists. PMMA is one of the best-known positive X-ray resists, although it lacks sufficient sensitivity to be of practical use (122,123). One attempt to increase the sensitivity of methacrylate polymers is the incorporation of more-reactive groups that, upon exposure, produce large amounts of volatile products (124). Possibly, dissolution is enhanced in the exposed resist as a result of gas-induced microporosity. Incorporation of metals such as Tl or Cs into MMA-MAA copolymers (123) or fluorine atoms... 

Table 5.6 Typical properties of methacrylate polymer concrete...

Table 3.1 summarizes the lithographic properties of methacrylate polymers 54). These polymethacrylates all exhibit similar UV absorptions with optical densities of 0.27-0.47 xm" at 215 nm, which is considerably less than that of AZ1350J in the near-UV region (0.87 jim at 405 nm). This low absorption represents ineflScient use of flux and is one reason for the low sensitivity of the system. 

In solution, the thermal reversion of methacrylate polymers substituted with spirobenzopyrans was often accompanied by a spectral shift of the photomerocyanines and a deviation from first-order kinetics. These observations were ascribable to intermolecular interaction between the merocyanine form and the ester residue of methyl methacrylate. This was supported by the emergence of photoviscosity effects in solutions of these photochromic polymers. 

S. H. Chen. "High-Pressure Carbon Dioxide Sorption in a Series of Methacrylate Polymers and... 

Intermediate Chemicals. The second category is intermediate chemicals. The chemical industry, which is its own best customer, buys many of this type of chemical to react with other materials to produce an end product. Such materials include epichlorohydrin, used as an intermediate in the manufacture of epoxy resins, acetone, an intermediate in the formulation of methacrylate polymers, and ethyl formate, used to synthesize vitamin Bi. 

TABLE 21.1 Glass-Transition Temperatnre, T, of Methacrylate Polymers... 

PEO is a fairly basic polymer and this character is stronger than in the case of methacrylate polymers. 

Chem. Descrip. Lauryl-myristyl methacrylate, MEHQ stabilizer Uses Emulsifier, dis rsant for emulsion polymerization monomer for mfg. of methacrylate polymers/copolymers, lymers us as oil additives, vise, index improvers, pour pt. depressants internal plasticizer for adhesives, UV-curable resins, ar waterproofing coatings Properties Pale yel. liq. sp.gr. 0.9 flash pf. 80 C add no. 0.15 max. hyd. no. 12 max. 

A third pyrolysis behavior is evidenced by polymers such as poly(methyl methacrylate). Because of the structure of methacrylate polymers (structure Vll), the favored degradation is essentially a reversion to the monomer. 

The qualitative aspect of methacrylate polymer pyrolysis and the quantitative determination of recovered monomer have been described. What remains to be discussed is a quantitative assessment of monomeric composition in a copolymer... 

The structures of the polymers examined in this set of experiments are depicted in Figure 1 along with the refractive indices, qo. A detailed discussion of the effect of fiuorination on the refractive index of methacrylate polymers has been presented elsewhere (7). All of the polymers examined had poly(methyl methacrylate) equivalent molecular weights greater than 300,000 g/mol. 

CALORIMETRIC BEHAVIOR OF METHACRYLIC POLYMERS. GRISKEYRG HUBBELL D 0 J APPL POLYM SCI... 

Ohsedo, Y., I. Imae, and Y. Shirota. 2003. Synthesis and electrochromic properties of a new family of methacrylate polymers containing pendant oligothiophenes. J Polym Sci Part B Polym Phys 41 2471-2484. 

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