Polymerization of 2,2‐dimethyltrimethylene carbonate with tri‐ sec ‐butoxyaluminium; a kinetic study

The polymerization of 2,2‐dimethyltrimethylene carbonate (DTC, 1 ) with tri‐ sec ‐butoxyaluminium (Al(O‐ sec ‐Bu) 3 ) proceeds with suppression of macrocyclics formation. The propagation of the polymerization proceeds pseudoanionically via insertion. Within the scope of a kinetic treatment, the time‐conversion relationship was determined for the polymerization of DTC with Al(O‐ sec ‐Bu) 3 as initiator and toluene as solvent. For a polymerization temperature between 15°C and 74°C, the apparent rate constant was found to be between 0,1 and 1,0 L · mol −1 · s −1 . Using the Arrhenius plot the experimental temperature coefficient (20,6 kJ · mol −1 ) as well as the frequency factor of the polymerization (1,3 · 10 3 L · mol −1 · s −1 ) were determined. Investigation of the dependence of the rate of polymerization on the initiator concentration revealed a degree of aggregation of 2 for the active species.