Copolymerization ethylene/styrene

Luo, Y. Baldamus, J. Hou, Z. Scandium half-metaUocene-catalyzed S5mdiospecific polymerization and styrene-ethylene copolymerization Unprecedented incorporation of syndiotactic styrene-styrene sequences in styrene-ethylene copolymers. J. Am. Chem. Soc. 2004,126, 13910-13911. 

Beside the homopolymerization of BD Nd-based Ziegler/Natta catalyst systems are also applied for the homopolymerization of IP, the copolymerization of the dienes BD and IP, the homopolymerization and copolymerization of substituted dienes as well as for the copolymerization of BD with alkenes such as styrene, ethylene and other ethylene derivatives. 

More industrial polyethylene copolymers were modeled using the same method of ADMET polymerization followed by hydrogenation using catalyst residue. Copolymers of ethylene-styrene, ethylene-vinyl chloride, and ethylene-acrylate were prepared to examine the effect of incorporation of available vinyl monomer feed stocks into polyethylene [81]. Previously prepared ADMET model copolymers include ethylene-co-carbon monoxide, ethylene-co-carbon dioxide, and ethylene-co-vinyl alcohol [82,83]. In most cases,these copolymers are unattainable by traditional chain polymerization chemistry, but a recent report has revealed a highly active Ni catalyst that can successfully copolymerize ethylene with some functionalized monomers [84]. Although catalyst advances are proving more and more useful in novel polymer synthesis, poor structure control and reactivity ratio considerations are still problematic in chain polymerization chemistry. 

The fact that ethylene will copolymerize at high pressures is rather fortunate from not only a commercial but also a theoretical view, since it has long been believed that monomer reactivity ratios might be better correlated according to a scheme based on ethylene rather than the currently used Q-e correlation in which styrene is taken as the reference standard. However, until recently no quantitative data on ethylene copolymerizations have been available upon which to base such a scheme. 

Some data recently obtained on high pressure ethylene copolymerizations illustrate the quantitative aspects of an ethylene-based Q-e scheme (6). In Figures 3 and 4 copolymer composition curves for the ethylene-vinyl chloride and the ethylene-vinyl acetate copolymerizations are given. The monomer reactivity ratios for these two systems are tabulated in Table III along with Q values and e values for vinyl chloride and vinyl acetate calculated using ethylene as the standard (Q = 1.0 and g = 0). These Q and e values may be compared with those obtained using styrene as the standard. 

Predict the extent of reaction at which gelation would occur in the following two vinyl-divinyl systems, both containing 1 mol% of the divinyl component (a) styrene-ethylene glycol dimethacrylate and (b) methyl methacrylate-divinyl benzene. Assume that the reaction conditions for the two systems are such as to yield the same DP. of 1000 for the uncrosslinked polymer. Take the r and T2 values from Table 7.1 for the analogous vinyl-vinyl copolymerizations. [Ans. (a) Pc = 0.015 (b) p, = 0.012.]... 

Attempted polymerization of styrene, ethylene/styrene copolymerization -... 

Daniello, C., Decandia, F., Oliva, L. and Vittoria, V. (1995) Correlation between microstructure and physical-properties in styrene ethylene copolymers. Journal of Applied Polymer Science 58, 1701-1706. Sernetz, F.G., Mulhaupt, R., Fokken, S. and Okuda, J. (1997) Copolymerization of ethene with styrene using methylaluminoxane-activated bis(phenolate) complexes. Macromolecules 30, 1562-1569. 

METALLOCENE-CATALYZED ETHYLENE COPOLYMERIZATION WITH STYRENE AND CYCLOOLEFINS... 

Caporaso, L. Izzo, L. Sisti, L Oliva, L. Stereospecific ethylene-styrene block copolymerization with a/wa-zirconocene-based catalyst. Macromolecules 2002, 35, 4866-4870. 

Dispersion (styrene aery late/aery late/ vina-ethylen-copolymere/VeoVa) Silicone (functionalized Polydimethylsiloxane)... 

This section contains experimental results relating to the structure of different copolymers of high olefins. All data are listed under the main olefins used for copolymerization ethylene, propylene, butene-1, 3-methylbutene-l, 4-methyIpentene-l, and styrene. When such a classification is used, it is inevitable that some copolymers will be mentioned twice (e.g. ethylene-styrene and styrene-ethylene copolymers). Where this occurs, the data on copolymer structures are given under the first... 

Figure 5.3 Plots of styrene (mol %) in copolymer versus [styrene]/[ethylene] molar ratio for copolymerization of ethylene with styrene (Table 5.3). Catalyst Cp TiCl2(0-2,6-Tr2C6H3) [Cp = l,2,3-Me3C5H2 (6, O), l,2,4-Me3C5H3 ( ), l,3-Me2C5H3 (7, ), ferf-Bu (8, )] [Me2Si(C5Me4)(N Bu)]TiCl2 (la, ) [13b].

Hydrocarbon resins (qv) are prepared by copolymerization of vinyltoluene, styrene, and a-methylstyrene in the presence of a Eriedel-Crafts catalyst (AlCl ). These resins are compatible with wax and ethylene—vinyl acetate copolymer (197). 

In order to increase the solubiUty parameter of CPD-based resins, vinyl aromatic compounds, as well as other polar monomers, have been copolymerized with CPD. Indene and styrene are two common aromatic streams used to modify cyclodiene-based resins. They may be used as pure monomers or contained in aromatic steam cracked petroleum fractions. Addition of indene at the expense of DCPD in a thermal polymerization has been found to lower the yield and softening point of the resin (55). CompatibiUty of a resin with ethylene—vinyl acetate (EVA) copolymers, which are used in hot melt adhesive appHcations, may be improved by the copolymerization of aromatic monomers with CPD. As with other thermally polymerized CPD-based resins, aromatic modified thermal resins may be hydrogenated. 

During this early period, a very ingenious free-radical route to polyesters was used to introduce weak linkages into the backbones of hydrocarbon polymers and render them susceptible to bio degradabihty (128—131). Copolymerization of ketene acetals with vinyl monomers incorporates an ester linkage into the polymer backbone by rearrangement of the ketene acetal radical as illustrated in equation 13. The ester is a potential site for biological attack. The chemistry has been demonstrated with ethylene (128—131), acryhc acid (132), and styrene (133). 

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