Hydrocarbonate oligomer

Prans, J.K. Vietzke, J.-P. Strassner, M. Rapp, C. Hintze, U. Konig, W.A. Characterization of Low Molecular Weight Hydrocarbon Oligomers by Laser Desorp-tion/Ionization-TOF-MS Using a Solvent-Free Sample Preparation Method. Rapid... 

More recent work on hydrocarbon oligomers by T. Suzuki established the biodegradation of oligomers of cis-1,4-polyisoprene,(23) polybutadiene,(24) polyethylene,(25) and polystyrene(26). 

Property PU-I pu-n Hydrocarbonate oligomer Thiokol Silicone organic oligomer... 

TEOA, as electron donor yields upon illumination in the presence of C02 and the Ru-colloid, methane as major photoproduct, cp = 4 x 10 4, and ethylene and ethane at lower yields, cp = 7.5x 10 5 and cp = 4x 10 5 respectively. In this photosystem, reductive ET quenching of excited Ru(bpz) + yields the reduced photoproduct Ru(bpz)j (E° = —0.86 V vs. SCE) that mediates the reduction of COz to methane and hydrocarbon oligomers (Fig. 30a). Interestingly, the reduced photoproduct Ru(bpz)J although thermodynamically capable, does not effect H2-evolution from the system. On the other hand, a series of photosystems composed of Ru(bpy) + as photosensitizer, TEOA as sacrificial electron donor and different bipyridinium electron acceptors (23)-(26) exhibit non-specificity, and... 

Figure 5 Yield of DEE ( O = 363 K and = 378 K), and yield of hydrocarbons (oligomers of isobutene excluded, = 363 K and = 378 K), versus contact time.

All of the hydrocarbon oligomers whose structures have been drawn above are olefinic with one double bond per molecule. Hydrogenation to... 

In hydrodynamic lubrication considerable emphasis is placed on the temperature coefficient of viscosity. Figure 17-1 illustrates the extent of the control that can be exercised over this important parameter in the synthesis of hydrocarbon oligomers. Viscosity data are plotted on the... 

The term hydrocarbon resins refers to hydrocarbon oligomers derived from coke-oven gas, coal-tar fractions, cracked and deeply cracked petroleum stocks, essentially pure hydrocarbon feeds, and turpentines. Typical hydrocarbon resins (HRs) include coumarone—indene resins (ClRs), petroleum resins (PRs), styrene polymers (SPs), cyclopentadiene resins (CPRs), and terpene resins (TRs). 

McClain et al. used poly(FOA) as the C02-philic segment of a nonionic surfactant, where poly(FOA) was copolymerized with a C02-insoluble polystyrene (PS) segment to form a block copolymer (Fig. 5) (32). Because of the solubility differences of the two segments, block copolymer molecules assemble into a miceiie, where the C02-phobic PS segments are found in the micelle core, and are surrounded by the C02-philic poly(FOA) segments. These micelles were used to solubilize C02-phobic hydrocarbon oligomers, where 99% of the hydrocarbon oligomers localized in the core of the micelle. 

Decafluorobiphenyl [434-90-2] C F C F (mol wt, 334.1 mp, 68°C bp, 206°C), can be prepared by I Jllmann coupling of bromo- [344-04-7] chloro- [344-07-0] or iodopentafluorobenzene [827-15-6] with copper. This product shows good thermal stabiHty decafluorobiphenyl was recovered unchanged after 1 h below 575°C (270). Decafluorobiphenyl-based derivatives exhibit greater oxidative stabiHty than similar hydrocarbon compounds (271). Therm ally stable poly(fluorinated aryl ether) oligomers prepared from decafluorobiphenyl and bisphenols show low dielectric constant and moisture absorption which are attractive for electronic appHcations (272). 

Hydrocarbons. Synthesized hydrocarbons are the most popular of the synthetic base stocks. These are pure hydrocarbons (qv) and are manufactured from raw materials derived from cmde oil. Three types are used olefin oligomers, alkylated aromatics, and polybutenes. Other types, such as cycloahphatics, are also used in small volumes in specialized apphcations. 

Other high molecular weight hydrocarbon polymers are not biodegradable, but oligomers of <7j -l,4-isoprene (83), butadiene (84), and styrene (85), are degradable. And there has been further confirmation of biodegradation of oligomeric ethylene (86). 

Figure 13.22 shows the resolution of the surfactants Tween 80 and SPAN. The high resolution obtained will even allow the individual unreacted ethylene oxide oligomers to be monitored. Figure 13.23 details the resolution of many species in both new and aged cooking oil. Perhaps the most unique high resolution low molecular weight SEC separation we have been able to obtain is shown in Fig. 13.24. Using 1,2,4-trichlorobenzene as the mobile phase at 145°C with a six column 500-A set in series, we were able to resolve Cg, C, Cy, Cg, C9, Cio, and so on hydrocarbons, a separation by size of only a methylene group. Individual ethylene groups were at least partially resolved out to Cjg. This type of separation should be ideal for complex wax analysis.

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