Degree of reaction

Theories of Gelation. The classical or mean field theory of polymeri2ation (4) is useful for visuali2ing the conditions for gelation. This model yields a degree of reaction, of one-third at the time of gelation for chemical species having functionaUty equal to four. Two-thirds of the possible... 

Having two degrees of reaction available facilitates the matching of turbocompressors in nitric acid plants, especially in dual-pressure installations, because these two different degrees of reaction may be mixed within the same compressor. 

The degree of reaction in an axial-flow compressor is defined as the ratio of the change of static head in the rotor to the head generated in the stage... 

Figure 9-4. Turbine velocity triangles showing the effect of various degrees of reaction.

Figure 6-5. Velocity diagrans for various degrees of reaction in an axial-flow compressor stage. (Reprintad with permission of MaemHIan PublisMng Company from Principles ofTuttomachinery by D. G. Shepherd, Macmiiian Publishing Company, 1956)...

Any effect of Mach number is experienced by rotor and stator equally and thus neither (or both) are limiting, and this Mach number will be lower than for other degrees of reaction under the conditions stated. If equal lift and drag are assumed in both rotor and stator, then optimum efficiency is obtained with R = 0.5 and VJu = 0.5. Although the latter is not always true, it does provide a useful criterion. Furthermore, the blade angles are similar in rotor and stator, which may be an advantage in the... 

For a given degree of reaction and value of or flow rate, a choice can be made of the stagger angle or setting of the blades. From the consideration of two defining equations ... 

The weight fraction of o -mer calculated according to Eq. (36) for a trifunctional monomer is shown in Fig. 69 for several degrees of reaction. The curves resemble those for the polymers of an A—R—B2 monomer shown in Fig. 66, with the important difference that they do not vanish into the axis at a = ac. This is simply a consequence of the fact that condensation is far short of completion at the critical point. 

Hydroformyl ati on of Polybutadiene - A number of hydroformyl at ion experiments were performed using the automated batch reactor system in order to synthesize the hydroformylated polybutadiene with varying degree of reaction completion (2 to 20% of the total C=C present). The following reaction conditions were employed PBD = 1.55 x 103 mol/m3, RhH(CO) (P(C6HJ3 )3 = 0.58... 

Figure 8. Calculated PTMO volume fraction in the TEOS-PTMO gel with respect to the initial PTMO weight fraction. The degree of reaction is the percentage of TEOS which converts into Si02.

In general, the CBD process starts by a quick mixing of stable solutions and proceeds under the influence of temperature control and stirring. The reaction advances as a function of time. The degree of reaction a (the ratio between the amount of substance that has reacted and the total amount able to react) can be expressed by the following equation24 ... 

To deduce the degree of reaction, one may use equation 8.286 with different integer values of n. The value of n that yields a straight line in a (c) — c,) " versus t plot is the order of reaction. 

Discuss qualitatively the course of the radical copolymerization of each of the following comonomer pairs in terms of the degree of reaction at which gelation would be expected to occur ... 

Two different sets of concentration conditions may be given. If the initial concentrations of all four species are given, the concentrations after any degree of reaction may be expressed as... 

Mechanical synthesis by cold mastication of rubber and monomers depends on the reaction condition (monomer concentration, temperature, solvent concentration, atmosphere, presence of transfer agents, or catalyst) and on the physical and chemical properties of the rubbers, the monomers and the product interpolymers. A critical factor is the shear stress developed in the system rather than instrumentally-defined shear rates. The degree of reaction of polymer and consequently also the concentration of free macroradicals depends on stress. As a consequence, the influence of the above parameters may be connected to their influence on the viscosity of the reaction medium since an increase in viscosity causes an increase in stress at constant shear rate. 

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