Hydrogenated butadiene

Another method to hydrogenate butadiene occurs during an oxidation—reduction reaction in which an alcohol is oxidi2ed and butadiene is reduced. Thus copper—chromia or copper—2inc oxide cataly2es the transfer of hydrogen from 2-butanol or 2-propanol to butadiene at 90—130°C (87,88). 

Flammable gases and vapors include acetylene, hydrogen, butadiene, ethylene oxide, propylene oxide, acrolein, ethyl ether, ethylene, acetone, ammonia, benzene, butane, cyclopropane, ethanol, gasoline, hexane, methanol, methane, natural gas, naphtha, and propane. 

Group B Hydrogen and fuel gases containing >30% hydrogen, butadiene, ethylene oxide, proplyene oxide, and acrolein... 

Figure 1. Ultimate tensile strength (

Reduction of a cobalt(II) halide in presence of 2,2 -bipyridyl with zinc in THF-ethanol leads to cobalt(I)-bipyridyl complexes which hydrogenate butadiene to cis-2-butene at 25 °C and normal pressure of hydrogen. For different halides the rate decreases in the order I>Br>Cl. 1,10-Phenanthroline complexes were also active.64 Here again, the catalyst does not tolerate an excess of diene. The proposed mechanism for the hydrogenation is given in Scheme 4. 

TRI-BLOCK COPOLYMER OF STYRENE-HYDROGENATED BUTADIENE-STYRENE [S-BH-S] [6]... 

TEM images of blends of S-B(h)-S with S/DPE(15) and S/DPE(30) are shown in Figure 25.16. The largest particles are about 1 p.m, which seems promising for toughening. Within the particles the typical lamellar structure of block copolymers can be seen. The white lines are the unstained hydrogenated butadiene and the dark regions the stained polystyrene phases. 

The resulting TPE can either be used alone or blended with aliphatic oil and polypropylene. In the former case a higher tensile strength and elongation at break are obtained in comparison with the commercially available styrene-hydrogenated butadiene-styrene block copolymers, especially at high temperatures. 

Not only metals but some oxide catalysts are active in diene hydrogenation ZnO modified by Sn(CH3)4 afforded 1-butene in hydrogenation of butadiene at room temperature. Reduced and sulfided moUbdena on alumina catalyst hydrogenated butadiene and cyclohexadiene selectively5 . When the transition metal complex Mo(CO)6 was encapsulated in NaY zeolite cages, it converted //wnv-l, 3-pcnladicnc to cA-2-pentene and 1,4-pentadiene to c -l,3-pentadiene at 150°C °. Cr(CO)3 encaged in LiX or NaX zeolite was efficient and selective in butadiene hydrogenation to cw-2-butene . ... 

Star-branched lonomers composed of short sulfonated polystyrene outer blocks and hydrogenated butadiene or isoprene inner blocks, with narrow molecular weight distributions have been synthesized by living... 

The selectivity of metal catalysts improves in some reactions with alloying for example the alumina-supported Pd-Cu catalyst hydrogenates butadiene to 1-butene with 99% selectivity, i.e. the isomerization is less than 1%. The explanation is that hydrogen adsorption decreased on the Cu-containing catalysts" . Similarly, better selectivities were observed with a polymer anchored Pd, or a Pd-Co catalyst in the gas-phase hydrogenation of butadiene and cyclopentadiene in a hollow-fiber reactor" and in the liquid-phase hydrogenation of 1,5-hexadiene with Pd-Ag catalyst". ... 

Shell Oil Co. (1977) Lubricating Composition Containing Hydrogenated Butadiene-... 

Linear low-density polyethylene (LLDPE) and PS resins were the same as described previously (Chapter 21). The various block copolymers that were used as compatibilizers have also been described (I). A series of crystalline copolymers (Q series) was prepared by hydrogenation of diblock and triblock copolymers of styrene and butadiene [styrene-hydrogenated butadiene (SEB) and styrene-hydrogenated butadiene—styrene (SEBS)J (1). Triblock copolymers of styrene and butadiene [styrene-butadiene-styrene (SBS)] and a noncrystalline hydrogenated block copolymer (SEBS) (Kraton) were supplied by Shell Chemical Co. Diblock copolymers of styrene and butadiene [styrene-butadiene (SB) (Vector)] were obtained from Dexco Polymers. The characteristics of the resins are given in Table I. 

Figure 3. Selectivities of hydrogen, butadiene, benzene, and polycyclics in the thermal reaction of ethylene...

Since the dimensions to be probed are of the order of few nanometers, the most useful microscopic method would be that of the transmission electron microscopy (TEM). Using this technique Fayt et al. [1986] observed location of P(S-b-HB) compatibilizer in a PE/PS blends. The authors inserted a short sequence of isoprene between the styrenic and hydrogenated butadiene blocks. After staining the isoprene double bonds with OsO, the authors were able to observe presence of the copolymer at the interface between the matrix and dispersed phase. Thickness of the interphase could then be measured. The experiments also demonstrated presence of the added compatibilizer as dispersed micelles inside the PE phase. This technique is applicable, however, only when selective staining affects only the compatibilizer. 

LDPE/PS LLDPE/PS HDPE/PS hydrogenated butadiene-b-styrene diblock copolymer (HPB-b-PS) Eayt et al., 1981, 1982, 1986... 

Heterogeneous Pt catalysts were prepared by controlled thermolysis of salts of [Pt3(CO)6ls, which had been deposited in the hexagonal channel of the mesoporous zeolite FSM-16. The catalysts were active for hydrogenation of ethylene at 300 K. With a partially decarbonylated catalyst, 1,3-butadiene was selectively hydrogenated to 1-butene complete decarbonylation above 463 K gave a Pt catalyst which completely hydrogenated butadiene to butane. ... 

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