Temperature dependence tetraline

Degradation in the presence of solvents has also been applied to the conversion of other styrenic polymers, such as poly(p-methylstyrene) and poly(styrene-allyl alcohol).64,65 Figure 4.11 shows the temperature dependence of the conversion of poly(p-methylstyrene) when using phenol, 1-methyl-naphthalene and tetralin as solvents. In this case, tetralin leads to the greatest degradation below 370 °C, whereas the order is reversed above that temperature. These results indicate that the effect of the solvent in the degradation of styrenic polymers is strongly influenced by the temperature. 

Overall reaction rates for the naphthalene and tetralin were based on generalised Langmuir-Hinshelwood kinetics [14] according to equations 7 and 8. Temperature dependency of rate constants ko, k and kr was described by Arrhenius law and adsorption equilibrium constants by the van t Hoff equation. 

Above 100°C, most polyolefins dissolve in various aHphatic and aromatic hydrocarbons and their halogenated derivatives. For example, polybutene dissolves in benzene, toluene, decalin, tetralin, chloroform, and chlorobenzenes. As with other polyolefins, solubiHty of PB depends on temperature, molecular weight, and crystallinity. 

Previously we have shown that phenolic compounds have a remarkable positive effect (4) on the coal liquefaction in the presence of Tetralin, depending strongly on the character of coal as well as on the concentration of phenols. The effect of phenols on the decomposition of diaryl ethers will give a good explanation for the previous results, because aliphatic ether structures of some young coals will be decomposed rapidly at relatively low temperatures and so the rate of coal dissolution will not be affected by the addition of phenols, on the other hand, the polycondensed aromatic ether structures will be decomposed effectively by the addition of phenols in the course of coal liquefaction. 

The most surprising observation from low temperature reactions was the formation of adducts between good donor solvents (Tetralin, octahydrophenanthrene, tetrahydroquinoline) and acceptor radicals. The resulting adducts were not of a single predominant structure. In particular, several isomers of toluene-Tetralin were formed as well as di-Tetralin. Several of these reactions were done with D -Tetralin which permitted the firm identification of the Tetralin moiety in the adducts. GLC-MS studies indicated that the Tetralin may be bonded to phenyl, benzyl, benzyloxy- or phenoxy-groups, depending on the acceptor used. 

The enantioselective benzylic hydroxylation of indan and tetralin can be achieved with M. isabellina, affording 78 % conversion to 1-indanol (64 % yield, 86 % (11 )- ee) in a 2-day incubation and 52 % conversion to 1-tetralol (38 % yield, 92 % (11 )- ee) in a 4-day incubation. The good yields and ee allow their use in future scahng-up processes however, to avoid the lack of efficiency, careful control of the temperature, pH and medium is necessary, since the reactions are strongly dependent on the incubation and reaction conditions. Tables 12.2 and 12.3 give details of some of the different incubation condi-tions/results and time-course analysis found in the benzyhc hydroxylation of indan and tetrahn mediated by M. isabellina CCT3498. 

Polyethylene is, depending on the molecular weight, a waxy or solid, crystalline substance. Following the above-mentioned procedure, a high molecular crystalline product with a melting range around 130 C is obtained. At room temperature it is insoluble in all solvents. At higher temperatures (100-150 °C) it can be dissolved in aliphatic and aromatic hydrocarbons.Viscosity measurements can be performed in xylene,tetralin or... 

A " -octalin was detected in measurable amount almost immediately after tetralin was observed, whereas no more than traces of A -octalin were detected, and in only a few experiments. Octalin formation was highly dependent on tetralin A " -octalin formation was favoured with the high concentration and conversion of tetralin that typically occurred at high temperature with high initial naphthalene concentration. 

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