Alpha-methylstyrene

Alpha-Methylstyrene Alpha-Methylstyrene Monoammonium Ammonium Phosphate... 

A typical phenol plant based on the cumene hydroperoxide process can be divided into two principal areas. In the reaction area, cumene, formed by alkylation of benzene and propylene, is oxidized to form cumene hydroperoxide (CHP). The cumene hydroperoxide is concentrated and cleaved to produce phenol and acetone. By-products of the oxidation reaction are acetophenone and dimethyl benzyl alcohol (DMBA). DMBA is dehydrated in the cleavage reaction to produce alpha-methylstyrene (AMS). 

The recovery area of the plant employs fractionation to recover and purify the phenol and acetone products. Also in this section the alpha-methylstyrene is recovered and may be hydrogenated back to cumene or recovered as AMS product. The hydrogenated AMS is recycled as feedstock to the reaction area. The overall yield for the cumene process is 96 mol %. Figure 1 is a simplified process diagram. 

The neutralized cleavage product, consisting of acetone, phenol, water, hydrocarbons, and trace organic impurities, is separated in a series of distillation columns. Also in this section alpha-methylstyrene is either recovered as a product or hydrogenated to cumene. 

Isocyanates can be added to solvent-borne CR adhesive solutions as a two-part adhesive system. This two-part adhesive system is less effective with rubber substrates containing high styrene resin and for butadiene-styrene block (thermoplastic rubber) copolymers. To improve the specific adhesion to those materials, addition of a poly-alpha-methylstyrene resin to solvent-borne CR adhesives is quite effective [76]. An alternative technique is to graft a methacrylate monomer into the polychloroprene [2]. 

K. M. Zheng, S. C. Greer. Living poly(alpha-methylstyrene) near the poly-... 

S. S. Das, A. Pophs-Andrews, S. C. Greer. Living poly(alpha-methylstyrene) near the polymerization line. 4. Extent of polymerization as a function of temperature. J Chem Phys 702 2951-2959, 1995. 

Song, J., Bodis, J., and Fhiskas, J.E. Direct functionalization of poly isobutylene by living initiation with alpha-methylstyrene epoxide, J. Polym. Set, Polym. Chem., 40, 1005, 2002. 

Poly(alpha-methylstyrene) Poly(propylene sulfide) Triblock... 

Polystyrene and poly(alpha-methylstyrene) Polystyrene and poly(alpha-methylstyrene) Polystyrene and poly(alpha-methylstyrene) Poly(methyl methacrylate)... 

Polyesters, polyurethanes Polyesters, nylons, polyurethanes Polypropylene, LDPE, PMMA, poly(alpha-methylstyrene) Polybutadienes, polyisoprene... 

Polymers of alpha methylstyrene are usually low-molecular-weight and have the following repeating unit ... 

These polymers, which are commercially available, are not thermally stable and decompose to produce the monomer when heated. Copolymers of alpha methylstyrene with methyl methacrylate or styrene are transparent plastics with heat deflection temperatures greater than that of PS. 

There is some reason to expect that conversion of the anhydride to a half-ester might reduce the sensitivity of the copolymers. Hiraoka (10) determined the relative sensitivities of PMMA, PMA (polymethacrylic acid) and PMA AN (polymethacrylic anhydride) by measuring the gaseous products (CO, C02, and H2) given off when these polymers were exposed to electron beam radiation of 2.5 keV at 297 °K. He found that the G values (number of chemical events produced per 100 eV of absorbed radiation) for the removal of side groups are 2.0, 7.4 and 16 for PMMA, PMA and PMA AN, respectively. Anderson (11) found a similar relative order of sensitivity. For copolymers of methylmethacryate with 25% dimethylitaconate, 25% monomethyl itaconate or 25% itaconic acid (or anhydride) the G(s) values were 1, 2, 3, respectively. For the copolymer of alpha-methylstyrene and monomethyl maleate, on the other hand, we find an increase in sensitivity by a factor of 2.5 over the corresponding anhydride as described below. 

Gaur, U. and Wunderlich, B. Study of microphase separation in block copolymers of styrene and alpha-methylstyrene in the glass transition region using quantitative thermal analysis. Macromolecules 13, 1618 (1980)... 

Functionalized ethylene oligomer ligated rhodium(I) complexes were prepared and the hydrogenation of various alkenes including 1-octene, delta-2-cholestene, cyclooctene, cyclododecene, styrene, alpha-methylstyrene was studied 94). 

Aromatic hydrocarbons Benzene, toluene, ethylbenzene, propylbenzene, 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, 1,2,3-trimethylbenzene, tert-butylbenzene, o,m,p-xylene, p-cymene, styrene, alpha-methylstyrene, naphthalene, methylnaphthalene... 

Tada, M., Sasaki, T. and Iwasawa, Y. Design of a novel molecular-imprinted Rh-amine complex on Si02 and its shape-selective catalysis for alpha-methylstyrene hydrogenation, J. Phys. Chem. B, 2004, 108, 2918-2930. 

Standard Preparation Place 25 mL of carbon disulfide in a 100-mL volumetric flask, cap with a serum stopper, and tare the flask to the nearest 0.1 mg. Using 50- xg syringes, inject 15 pL each of styrene and of alpha-methylstyrene (AMS), reweighing after each addition to obtain the weight of each solution injected. Record the weight, in milligrams, of styrene as wq and that of AMS as w2. Dilute to volume with carbon disulfide, and mix. Pipet 2 mL of this solution into a second 100-mL volumetric flask, dilute to volume with carbon disulfide, and mix. Finally, pipet 25 mL of the diluted solution into a third 100-mL volumetric flask, dilute to volume with carbon disulfide, and mix. 

Application A high-yield process to produce high-purity phenol and acetone from cumene with optional byproduct recovery of alpha methylstyrene (AMS) and acetophenone (AP). 

PIACA S) PAMS P(AMS AN) P(AN BR) PAN poly(acrylamide-co-styrene) poly(alpha-methylstyrene) poly(alpha-methylstyrene-co-acrylonitrile) poly(acrylonitrile-co-butadiene) polyacrylonitrile... 

Cowie, JMG, Elexpuru EM and McEwen IJ (1992) Observation of restricted miscibility in binary blends of poly(styrene-.v a/-acrylonitrile) and poly(alpha-methylstyrene-.v/az-acrylonitrile). Polymer 33 1993-5. 

Calculate the composition (mole fractions) of the initial terpolymer which would be formed from the radical polymerization of a feed containing 0.414 mol fraction methacrylonitrile (MAN), 0.424 mol fraction styrene (S), and 0.162 mol fraction alpha-methylstyrene (AMS). Reactivity ratios are ... 

A polymer with an active carbanionic end will initiate the polymerization of a different monomer if the initial macroion is more nucleophilic than the anion formed from the second monomer in the particular solvent/counterion environment. Thus alpha-methylstyryl anion (9-1) will initiate the polymerization of methyl methacrylate (Fig. 1-4) but the poly(methyl methacrylate) carbanion will not initiate polymerization of alpha-methylstyrene. 

---