T-Butylstyrene

Test of time-temperature superposabillty for the dielectric P data of low-M and middle-M poly-isoprene/poly(p-feri butyl styrene) (PI/PtBS) miscible blends as indicated. In panels (a)-(d), the sample code numbers of the blends denote Kh M of the components. The reference temperature is T, = 90°C for aU blends. The solid curves indicate the e" data of bulk PI corrected for the PI volume fraction in the blends. These curves are shifted along the axis to match their peak frequency with that of the blends. (Etata taken, with permission, from Chen, Q., Y. Matsumiya, Y. Masubuchi, H. Watanabe, and T. Inoue. 2008. Component dynamics in polyisoprene/ poly(4-tert-butylstyrene) miscible blends. MacrvmoJeades 41 8694-8711 Chen, Q., Y. Matsumiya, Y. Masubuchi, H. Watanabe, and T. Inoue. 2011. Dynamics of polyisoprene-poly(p-tert-butylstyrene) diblock copolymer in disordered state. Macnmiolecules 44 1585-1602 Chen, Q., Y. Matsumiya, K. Hiramoto, and H. Watanabe. 2012. Dynamics in miscible blends of polyisoprene and poly(p-terf-butyl styrene) Thermo-rheological behavior of components. Polymer ]. 44102-114.)... 

Chen, Q., Y. Matsumiya, Y. Masubuchi, H. Watanabe, and T. Inoue. 2008. Component dynamics in polyisoprene/poly(4-tert-butylstyrene) miscible blends. Macromolecules 41 8694 711. 

Figure 3.4. Illustration of phase inversion during polymerization (Molau, 1965). Electron micrographs (transmission) of thin sections of a graft copolymer of p-t-butylstyrene with polystyrene (90/10). (a) Polymerized to 5.3 % conversion before the inversion point. The poly(p-t-butylstyrene) phase is white, and the polystyrene phase is black, (b) Polymerized to 7.8% conversion phase inversion is just beginning to occur, (c) The same system polymerized to 13.3% conversion after the phase inversion point.

A significant variation in the stereochemistry is observed when the double bond is conjugated with a group that can stabilize a carbocation intermediate. Most of the examples involve an aryl substituent. Examples of alkenes that give primarily syn addition are cis- and tran -l-phenylpropene, cis- and tran5-)8-t-butylstyrene, 1-phenyl-4-t-butylcyclohexene/ and indene. The mechanism proposed for these additions features an ion pair as the key intermediate. Because of the greater stability of the carbocations in these systems, concerted attack by halide ion is not required for carbon-hydrogen bond formation. If the ion pair formed by alkene protonation collapses to product faster than rotation takes place, the result will be syn addition, since the proton and halide ion are initially on the same side of the molecule. 

In addition to a-olefins, p-t-butylstyrene can be used as a comonomer for the isotactic specific copolymerization with carbon monoxide with chiral induction [32]. Whereas bipyridyl as ligand gives a syndiotactic polymer, the Pd-catalyzed polymerization with ligand 11 leads to a polymer with isotacticity of over 98% and high optical activity ([4>]jj -536° (in CH2CI2)) [33, 34]. The BINAPHOS catalyst described above is also effective in this type of copolymerization [25]. 

Miscellaneous Extractions. Additional extractive separations using sulfolane involve (/) mercaptans and sulfides from sour petroleum (45) (2) /-butylstyrene from t-butylethylbenzene (46) (3) mixtures of dose boiling chlorosilanes (47) and (4) aromatics from kerosene (48—50), naphtha (49,51—53), and aviation turbine fuel (54). 

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