Ring-opening polymerization of 1,5-dioxepan-2-one initiated by a cyclic tin–alkoxide initiator in different solvents

✍ Scribed by Kajsa Stridsberg; Ann-Christine Albertsson

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 224 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990815)37:16<3407::aid-pola40>3.0.co;2-x

✦ Synopsis

Ring-opening polymerization of 1,5-dioxepan-2-one initiated by 1,1,6,6tetra-n-butyl-1,6-distanna-2,5,7,10-tetraoxacyclodecane was carried out in chloroform, dichloromethane, or 1,2-dichloroethane. Effects of reaction temperature, solvent, and monomer-to-initiator ratio were investigated. Polymerization kinetics showed a firstorder dependence on the monomer for polymerization in chloroform and dichloromethane at 40°C. The kinetic order with respect to the initiator were a first order when dichloromethane was used as the solvent, the order in initiator changed, depending on the initiator concentration when chloroform was used. A maximum in molecular weight was observed at 40°C when chloroform was used as the solvent. The change of solvent did not markedly alter the polymerization rate or the molecular weight of the polymers prepared, as expected from the coordination insertion mechanism. Depolymerization of the polymers formed was observed when the reaction was allowed to continue after complete monomer conversion in chloroform as reaction medium at 40°C.