Molecular weight distribution control in a semibatch living‐anionic polymerization. II. Experimental study

摘要

AbstractThis work constitutes an indirect verification of a theoretical method that allows the production of polymers with prespecified molecular weight distributions (MWDs), through semibatch living‐anionic homopolymerizations. The chemical system consisted of styrene with sec‐butyllithium, in a solvent mixture of cyclohexane and tetrahydrofurane (THF). The necessary flow profiles were applied by a pair of computer‐controlled pumps, and the produced MWDs were measured by size exclusion chromatography, with correction for nonuniform instrumental spreading. The main difficulty was the estimation of the initial moles of initiator and of the concentration of impurities in the monomer solution. For such estimation, a precalibration experiment was implem