Journal of Polymer Science Part A: Polymer Chemistry, Vol.57, No.9, 952-960, 2019
Cyclic poly(lactide)s via the ROPPOC method catalyzed by alkyl- or aryltin chlorides
A comparison of tributyltin chloride, dibutyltin dichloride, and butyltin trichloride as catalysts of ring-opening polymerizations (ROPs) of l-lactides at 160 degrees C in bulk reveals increasing reactivity in the above order, but only the least reactive catalysts, Bu3SnCl, yield a uniform reaction product, namely cyclic poly(L-lactide)s with weight average molecular weights (M-w's) in the range of 40,000-80,000. A comparison of dimethyltin , dibutyltin , and diphenyltin dichlorides resulted in the following order of reactivity: Me2SnCl2 < Bu2SnCl2 <