Figure 3.
The progress of the polymerization was monitored by observing the decrease in the IR absorbance of the monomer β-lactam carbonyl stretch (1784 cm−1, red) and the increase in the polymer amide carbonyl stretch (1693 cm−1, blue). Reaction conditions: THF, rt, [1] = 0.15 M, 2 mol% of 4-tert-butylbenzoyl chloride, and 5 mol% LiHMDS. Data recording began 30 sec after addition of the base.