Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Summary The compositions of copolymers of butadiene (B) and isoprene (I), produced by anionic copolymerization with sec-butyl lithium initiator in hexane at 20–40°C gave a good fit at low conversions to the terminal model for copolymerization. Non-linear, “best estimates” of the reactivity ratios rB and rI were 2.82 and 0.42, 1.72 and 0.36, 2.18 and 0.35 at 20, 30 and 40°C. The rates of copolymerization at conversions up to 98% of total monomer gave a smooth relationship with the instantaneous feed composition, calculated using the terminal model, at each temperature and independent of the initial feed composition. These results are in accord with the terminal model being applicable to this anionic copolymerization from low to hiqh conversions.
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