SAN copolymer by suspension polymerization. II. Bead size distribution and molecular weight

摘要

AbstractBeads of SAN copolymer produced by suspension polymerization have sizes distributed over the range of 0.2–3.0 mm; 70–80 of these are in the range of 0.4–0.8 mm diameter. Studies on molecular weight and molecular weight distribution showed that the average molecular weight of the polymer was higher with increasing sizes of beads. Fractionation of small‐, medium‐, and large‐sized beads as well as determination of molecular weight by GPC provided clear evidence that there is also an increase of polydispersity and higher molecular weight ends with increasing diameter of beads. This increase in molecular weight and polydispersity in larger beads is probably due to slow thermal polymerization in near absence of initiator toward the end of pol