Copolymerization of Styrene and Ethylene

Inoue and Shiomura [33] examined zirconium complexes for the ethylene-styrene copolymerization. They found alternating copolymer and homopolymer. The stereoregularity of the polymers was atactic. 

Suzuki and co-workers copolymerized styrene and ethylene by ansa-zircono-cene compounds [34]. The polymer produced was isotactic polystyrene with ethylene. They found that the phenyl group of the monomer coordinates to the active site and decreases the catalytic activity. 

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Polyoltfin Polyester Polyether/ amide block copolymers Block copolymers of styrene and butadiene or styrene and ieoprene Block copolymere of styrene and ethylene and/or butylene Siliecne-based, pseudo-interpenetrating networks ... 

Longo, R Grassi, A. Oliva, L. Copolymerization of styrene and ethylene in the presence of different syndiospecific catalysts. Makromol. Chem. 1990,191, 2387-2396. 

Aral, T. Ohtsu, T. Suzuki, S. Stereoregular and Bemoullian copolymerization of styrene and ethylene by bridged metallocene catalysts. Macromol. Chem. Phys. 1998,19, 327—331. 

Solution Polymerization These processes may retain the polymer in solution or precipitate it. Polyethylene is made in a tubular flow reactor at supercritical conditions so the polymer stays in solution. In the Phillips process, however, after about 22 percent conversion when the desirable properties have been attained, the polymer is recovered and the monomer is flashed off and recyled (Fig. 23-23 ). In another process, a solution of ethylene in a saturated hydrocarbon is passed over a chromia-alumina catalyst, then the solvent is separated and recyled. Another example of precipitation polymerization is the copolymerization of styrene and acrylonitrile in methanol. Also, an aqueous solution of acrylonitrile makes a precipitate of polyacrylonitrile on heating to 80°C (176°F). 

Polystyrene-g-poly(ethylene oxide) was synthesized by the copolymerization of styrene and styrenic PEO with CpTiCb/MAO catalyst [190]. In this case the macromonomer was prepared by first reacting the sodium salt of PEO-OH with NaH and then with a 5-fold amount of p-chloromethyl styrene. 

A few attempts have been made to copolymerize vinylcyclohexane with other monomers using coordination-type polymerization catalysts. The successful copolymerization of styrene and vinylcyclohexane [50] with a Zeigler-type catalyst has been reported. The copolymerization of the closely related monomer 4-vinylcyclohexene with ethylene using a Zr-based metallocene and methy-lalumoxane activator has been described [51]. 

Flydroxyl-capped poly (ethylene-co-butylene), a so-called Kraton, was converted into a macroinitiator via esterification with 2-bromopropionyl chloride, and then employed for the block copolymerizations of styrene and />acetoxystyrene (B-116 and B-117).403 A similar method is utilized for B-l 18 to B-121 where the esterification is with 2-bromoisobutyroyl bromide.341 A commercially available polybutadiene is also employed for B-122 via a similar transformation into the chloroacetyl group.404... 

Reactor designs are characterized as either homogeneous or heterogeneous. Typically, homogeneous reactors are well mixed stirred tanks (either batch or continuous), but can also be tubular reactors. They are widely used in the chemical industry from pilot plant to full-scale production. Examples include decomposition of azomethane, production of ethylene glycol, and the copolymerization of styrene and butadiene. 

Langer (13) has also disclosed the use of alkyllithium and dialkyl-magnesium tertiary diamine complexes as catalysts for copolymerization of ethylene and other monomers such as butadiene, styrene, and acrylonitrile to form block polymers. Examples are given in which polybuta-dienyllithium initiates a polyethylene block, as well as vice-versa. Random copolymers of these two were also prepared, and other investigators have used not only tertiary diamines but hexamethylphosphoramide (14) and tetramethylurea (15) as nitrogenous base cocatalysts in such polymerizations. Antkowiak and co-workers (11) showed the similarity of action of diglyme and TMEDA in copolymerizations of styrene and... 

Figure 1. GPC curves of graft copolymer, styrene homopolymer, a mixture of graft copolymer and homopolymer, and trunk polymer(EVNB) in the graft copolymerization of styrene onto ethylene-vinyl p-nitrobenzoate copolymer.

No.4, 2000, p. 1257-67 EMULSION COPOLYMERIZATION OF STYRENE AND POLY(ETHYLENE GLYCOL) ETHYL ETHER METHACRYLATE... 

Ribeiro, M. R. Portela, M. F. Deffienx, A. CramaU, H. Rocha, M. F. Isospecific homo- and copolymerization of styrene with ethylene in the presence of VCI3, AICI3 as catalyst. Macromol. Rapid Commuti. 1996,17, 461-469. 

The copolymerization of carbonyl monomes with alkenes has been even less studied than that between different carbonhyl monomers. The radiation-initiated copolymerization of styrene with formaldehyde proceeds by a cationic mechanism with a trend toward ideal behavior, r = 52 and r2 = 0 at —78°C [Castille and Stannett, 1966]. Hexafluoroacetone undergoes radiation-initiated copolymerization with ethylene, propene, and other a-olefins [Watanabe et al., 1979]. Anionic copolymerizations of aldehydes with isocyanates have also been reported [Odian and Hiraoka, 1972]. 

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