Potassium triphenylmethoxide

Table IV gives an example of our own work on the polymerization of a number of higher aldehydes. Potassium triphenylmethoxide—a soluble initiator—polymerized a number of higher aldehydes to crystalline isotactic poly aldehydes. Table V lists a number of alkali alkoxides and other related compounds used as initiators for the n-butyraldehyde polymerization. Neither the type of the alkoxide nor the cation is of any great importance for the polymerization rate, the polymer yield, and stereoregularity of the resulting polyaldehyde as long as the initiator is adequately soluble in the reaction mixture.

Initial reaction temperature, -75° C., initiator, potassium triphenylmethoxide solvent, propylene solvent monomer ratio, 4 1... 

Figure 2. Influence of the dielectric constant e of various solvents upon the polymerization of n-butyraldehyde. Initial reaction temperature, -75° C. time, one-half hour initiator, potassium triphenylmethoxide (0.13 mole %) solvent, n-butyraldehyde (ratio, 4 1)...

Polymerization of aldehydes can be accomplished only at low temperatures. The influence of temperature on aldehyde polymerization initiated by potassium triphenylmethoxide is shown in Figure 3 with n-butyraldehyde as the example. At -78° C. the polymerization goes to high conversions (95%) the conversion decreases substantially with increasing temperature. No polymerization is observed above -15° C. 

Figure 3. Conversion in n-butyraldehyde polymerizations potassium triphenylmethoxide (0.2 mole %) as initiator in 25% pentane solutions A = by gas chromatography, 0 = isolated and weighed. A = time dependence of conversion at -75° C. B = temperature dependence of conversion after 10 minutes reaction time...

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See also in sourсe #XX -- [ ]

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