Living polymerization of [o-(trifluoromethyl)phenyl]acetylene by a new catalyst system, MoOCl4-Et3Al-EtOH (1 : 1 : 4)

A new MoOCl4-based living polymerization catalyst, MoOCl4-Et3Al-EtOH (mole ratio 1 : 1 : 4)/anisole, has been developed. Polymerization of [o-(trifluo romethyl)phenyl]acetylene by this catalyst in anisole at 30 degrees C yield ed a polymer having very narrow molecular weight distribution ((M) over bar (w)/(M) over bar(n) = 1,02), a four-fold excess of ethanol over MoOCl4 was necessary to attain narrow molecular weight distributions. Multistage polym erization experiments clearly showed the living nature of the polymerizatio n, which was maintained in the temperature range of 0 to 30 degrees C. The absolute number-average molecular weight of the polymer measured by vapor p ressure osmometry could be correlated with the number-average molecular wei ght measured by gel permeation chromatography as follows: (M) over bar(n)(V PO) = 1,48 (M) over bar(n)(GPC). The propagation rate constant (k(p)) at 30 degrees C is 1,5 mol . L-1. s(-1).