Effect of catalyst concentration

The relative effectiveness of nucleating agents in a polymer can be determined by measuring recrystallization exotherms of samples molded at different temperatures (105). The effect of catalyst concentration and filler content has been determined on unsaturated polyesters by using dynamic thermal techniques (124). Effects of formulation change on the heat of mbber vulcanization can be determined by dsc pressurized cells may be needed to reduce volatilization during the cure process (125). 

Saturation of the oil with hydrogen is maintained by agitation. The rate of reaction depends on agitation and catalyst concentration. Beyond a certain agitation rate, resistance to mass transfer is eliminated and the rate oecomes independent of pressure. The effect of catalyst concentration also reaches hmiting values. The effects of pressure and temperature on the rate are indicated by Fig. 23-34 and of catalyst concentration by Fig. 23-35. Reaction time is related to temperature, catalyst concentration, and IV in Table 23-13. 

FIG. 23-35 Effect of catalyst concentration and stirring rate on hydrogenation of soybean oil. (Swern, ed., Baileys Industrial Fat and Oil Products, vol. 2, Wiley, 1979.)... 

The Effect of Catalyst Concentration, Temperature, and Residence Time on the Chemical Structure of Coal Hydropyrolysis Oils... 

The Effect of Catalyst Concentration The first parameter that was studied was the effect of the catalyst concentration. Samples impregnated with 1, 5, 10 and 15% tin as stannous chloride and a sample with no catalyst were hydrogenated at 450°C to investigate the effect that increasing catalyst concentration has on the composition of the oil (hexane soluble portion) formed. 

Conflicting results have been reported for the effects of catalyst concentration in the cobalt-catalyzed reaction. In early work, Hughes and Kirshenbaum (31) reported that these parameters were very influential in determining product composition high temperatures and high catalyst concentrations resulted in products containing decreased amounts of the... 

Effect of Catalyst Concentration on Product Composition in the Hydroformylation of Propylene Conducted in the Presence of Ethyl Orthoformate (32)... 

Fig. 19. Effect of catalyst concentration on rates to methanol and ethylene glycol by an iodide-promoted ruthenium catalyst (191). Reaction conditions 75 ml of N-methylpyrrolidone ( ) or sulfolane ( ) solvent, [KI] = 6[Ru], 850 atm, 230"C, H2/CO = 1.

We also studied the effect of catalyst concentration on the reaction and determined that the reaction could take place without catalysis, but that its speed was highly dependent upon the concentration of catalyst, both in the case of 72% perchloric acid and in the case of the boron trifluoride etherate. A workable level for the perchloric acid catalyst was found to be in the order of 3-4 grams per mole of the acid-ester charge. A catalyst level for the boron trifluoride etherate of 40 grams per mole of the acid component charge was satisfactory. 

Typical hydrogenation run. 3.Effect of catalyst concentration on reaction rate... 

Subsequently, several nonkinetic approaches (32) were directed toward determining the structure of the live chain ends (e.g., H-NMR and 13C-NMR). For example, Bywater and co-workers (58) studied the addition of r-butyllithium to 1,3-butadiene and obtained a complex PMR spectrum for the addition product. They examined the effect of catalyst concentration on the microstructure of the polybutadiene and found that at high catalyst levels, the vinyl content increased as shown in Table II. 

Effect of Catalyst Concentration. Since the effectiveness of AFR polymerization should depend on the number of active ends of the anionic polymer chain, it is of interest to study the effect of the change of anionic catalyst concentration on AFR polymer formation. At high catalyst levels the effect of catalyst concentration is difficult to demonstrate, but at low catalyst levels monomer conversion is directly related to the amount of TiCl3 used (Table XII). 

Table XII. Effect of Catalyst Concentrations on Conversion of Acrylates to Block Polymers0...

TABLE 3.7 Effect of Catalyst Concentration on Rate in the Hydrogenation of a Glyceride Oil over Pd-C ... 

With Tetramethylammonium Siloxanolate, The second system studied was the tetramethylammonium-siloxanolate-catalyzed equilibration process. The reaction temperature was held at 80 °C to avoid decomposition of the siloxanolate end groups. The effect of catalyst concentration on the disappearance of D4 is shown in Figure 3. The reaction of D4 proceeded fairly... 

As a result of the method of catalyst addition and because of its fairly viscous nature even as an —35 wt % solution in toluene, the same catalyst concentration could not be reproduced exactly from one catalyst system to another for comparison. The rate differences were sufficient, however, to compare the effects of catalyst concentrations and to examine the efficiency of the different catalysts. 

The Effect of Catalyst Concentration on Melt-polvmerization and Solid-state Heat-treatment. In the preparation of polyester-carbonates of different... 

Fig.3 Effect of catalyst concentration on the rate of hydroformylation of 1-octene using ethanol as a co-solvent [14],...

The same effect of catalyst concentration (catalyst NaOH) on the distribution of EO sequences/hydroxyl groups was observed in the synthesis of nonionic surfactants of polyethoxylated fatty alcohol types. Thus, by the transformation of 60-100% of the... 

Figure 4.25 The effect of catalyst concentration on the primary hydroxyl content MW = 4700-5000 daltons Ethoxylation temperature 130 °C...

Several different runs will be done with different acid concentrations to determine the effect of catalyst concentration on the rate of reaction. 

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