Polymer methyl methacrylate

The action of sulphuric acid alone upon acetone cyanohydrin affords a-methylacrylic acid. The methyl methacrylate polymers are the nearest approach to an organic glass so far developed, and are marketed as Perspex (sheet or rod) or Dialcon (powder) in Great Britain and as Plexiglass and Luciie in the U.S.A. They are readily depolymerised to the monomers upon distillation. The constitution of methyl methacrylate polymer has been given as ... 

Place 25 g. of methyl methacrylate polymer (G.B. Diakon (powder). Perspex (sheet) U.S.A. Lucite, Plexiglass) in a 100 ml. Claisen flask, attach an efficient condenser e.g., of the double smface type) and distil with a small luminous flame move the flame to and fro around the sides of the flask. At about 300° the polymer softens and undergoes rapid depolymerisation to the monomer, methyl methacrylate, which distils over into the receiver. Continue the distillation until only a small black residue (3-4 g.) remains. Redistil the hquid it passes over at 100-110°, mainly at 100-102°. The yield of methyl methacrylate (monomer) is 20 g. If the monomer is to be kept for any period, add 0 -1 g. of hydro quinone to act as a stabiUser or inhibitor of polymerisation. 

Another type of synthetic polymer-based chiral stationary phase is formed when chiral catalyst are used to initiate the polymerisation. In the case of poly(methyl methacrylate) polymers, introduced by Okamoto, the chiraUty of the polymer arises from the heUcity of the polymer and not from any inherent chirahty of the individual monomeric subunits (109). Columns of this type (eg, Chiralpak OT) are available from Chiral Technologies, Inc., or J. T. Baker Inc. 

Optics. Good optical properties and low thermal resistance make poly(methyl methacrylate) polymers well suited for use as plastic optical fibers. The manufacturing methods and optical properties of the fibers have been reviewed (124) (see Fiber optics). Methods for the preparation of Fresnel lenses and a Fresnel lens film have been reported (125,126). Compositions and methods for the industrial production of cast plastic eyeglass lenses are available (127). 

Various methacrylate esters have been disclosed as modifiers of DADC. Thus methyl methacrylate polymer may be dissolved in DADC and the sheets cast (22). When DADC is copolymerized with methyl methacrylate, a silane derivative may be added to control the release from the mold (23). 

Methyl Methacrylate Polymers with Enhanced Impact Resistance 413... 

METHYL METHACRYLATE POLYMERS WITH ENHANCED IMPACT RESISTANCE AND SOFTENING POINT... 

Spin orbitals, 258, 277, 279 Square well potential, in calculation of thermodynamic quantities of clathrates, 33 Stability of clathrates, 18 Stark effect, 378 Stark patterns, 377 Statistical mechanics base, clathrates, 5 Statistical model of solutions, 134 Statistical theory for clathrates, 10 Steam + quartz system, 99 Stereoregular polymers, 165 Stereospecificity, 166, 169 Steric hindrance, 376, 391 Steric repulsion, 75, 389, 390 Styrene methyl methacrylate polymer, 150... 

Figure 8. Computed drift curves for instantaneous and cumulative CCs of styrene-methyl methacrylate polymers initiated with AIBN...

N Thomas, AH Windle. Transport of methanol in poly(methyl methacrylate). Polymer 19 255-265, 1978. 

ISO 1628-6 1990 Plastics - Determination of viscosity number and limiting viscosity number - Part 6 Methyl methacrylate polymers ISO 7823-1 2003 Plastics - Poly(methyl methacrylate) sheets - Types, dimensions and characteristics - Part 1 Cast sheets... 

Com starch (comi) 7 wheat flour 4 sugar, powdered 9.6 methyl methacrylate polymer 6.3 cellulose acetate >10 magnesium, milled, 7.7 and aluminum, atomized, 2.5 (Refs 6 10)... 

M. Fowler, J. Barlow, and D. Paul, Effect of copolymer composition on the miscibility of blends of styrene-acrylonitrile copolymers with poly (methyl methacrylate), Polymer, 28(7) 1177-1184, June 1987. 

Physical Measurements. Molecular Weight. Intrinsic viscosities were determined using dilute solution viscometry (Cannon-Ubbelohde viscometers). For the poly (methyl methacrylate) polymer the following empirical expressions were used to obtain molecular weights (4) ... 

Gentilhomme A, Cochez M, Ferriol M, Oget N, Mieloszynski JL. Thermal degradation of methyl methacrylate polymers functionalized by phosphorus-containing molecules. Ill Cone calorimeter experiments and investigation of residues. Polym. Degrad. Stab. 2005 88 92-97. 

He XW et al. (1989) Poly(dimethylsiloxane)/poly(methyl methacrylate) interpenetrating polymer networks 1. Efficiency of stannous octoate as catalyst in the formation of poly(dimethylsiloxane) networks in methyl methacrylate. Polymer 30(2) 364-368... 

In Fig. 13 are shown typical spectra for 15% solutions of two methyl methacrylate polymers in chloroform. The polymers were prepared with (a) benzoyl peroxide in toluene at 100° and (b) n-butyllithium at — 62°. The large peak at the left is that of the chloroform solvent. The ester methyl group appears at 6.40r in both spectra, and is not affected by the chain conformation. There are three cc-methyl peaks, at 8.78t, 8.95 t, and 9.09r, whose relative heights vary greatly with the method of polymer preparation. Polymers prepared with n-butyllithium show a very prominent peak at 8.78r, the others being much smaller. Polymers prepared with benzoyl peroxide initiator show the same three peaks, but now the peak at 9.09r is the most prominent. 

Fig. ]3. NMR spectra of methyl methacrylate polymers prepared with (a) benzoyl peroxide in toluene at 100° and (i6J w-butyllithhim in toluene at —62°. The spectra are run on 15% solutions of the polymers in chloroform with 1% tetramethylsilane reference (r)...

Fig. 14. The probabilities Pi, and of formation of isotactic, syndiotactic, and heterotactic triads, respectively, as a function, of o, the probability of isotactic placement of monomer units during chain propagation. Experimental points at the left are for methyl methacrylate polymers prepared with free radical initiators . those at the right for polymers prepared with anionic initiators ( O) t peaks ...

Bovey, F. A., and G. V. D. Tiers Polymer NMR spectroscopy. II. The high resolution spectra of methyl-methacrylate polymers prepared with free radical and anionic initiators. J. Polymer Sci. 44, 173—182 (I960). 

Fig. 10. Elution profiles of similarly sized polystyrene and poly(methyl methacrylate) polymers by Th-FFF and SEC illustrating the chemical selectivity of Th-FFF. Reproduced from [2] with kind permission of Pergamon Press...

Materials. The dispersed phase of the dispersions contained, by weight 98.07% acrylic polymer beads, 0.8% benzoyl peroxide (98% active), 1% red acetate fibers, 0.03% red pigments, and 0.1% Ti02 pigment. The acrylic polymer beads were a 50/50 wt/wt blend of two suspension polymerized poly (methyl methacrylate) polymers with solution molecular weights of 160,000 and 950,000. Additives to the dispersed phase were those described above. The polymers were each reduced 1 vol % on the total dispersion volume to compensate for the additives. 

METHYL METHACRYLATE POLYMER see PKB500 METHA L METHACRYLATE RESIN see PKB500 N-METHYLMETHANYMINE see DOQ800 N-METHAEMETHANMllNE uith BOLANE (E.l) see DOR200... 

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