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Polymers of Carbonic Acid, 30 Ring‐Expansion Polymerization of Trimethylene Carbonate (TMC, 1,3‐Dioxanone‐2) with Dibutyltin Succinate or Adipate
Author(s) -
Kricheldorf Hans R.,
Stricker Andrea,
Gomurashvili Zaza
Publication year - 2001
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20010201)202:3<413::aid-macp413>3.0.co;2-r
Subject(s) - adipate , polymer chemistry , chemistry , polymerization , monomer , trimer , dicarboxylic acid , molecular mass , dimer , polymer , succinic acid , organic chemistry , enzyme
Macrocyclic crystalline dibutyltin succinate (Bu 2 SnSuc) and adipate (Bu 2 SnAd) were prepared in high yields from Bu 2 SnO and dicarboxylic acid. According to vapor pressure osmometry and MALDI‐TOF mass spectrometry, Bu 2 SnSuc is a cyclic trimer and Bu 2 SnAd a cyclic dimer. These macrocycles initiate a faster polymerization of TMC at 80°C than Sn(II) octanoate or Bu 2 Sn octanoate. The resulting polyTMC does not contain succinate or adipate groups, and the molecular weight ( M w ) is independent of the monomer to initiator ratio (M/I). Above 120°C a complete esterification and incorporation of the dicarboxylic acids takes place, and the identification of CH 2 OH end groups suggests that a ring‐expansion polymerization via insertion of TMC into Sn—O—CH 2 bonds proceeds. The number‐average molecular weights increase with the M/I ratio, but do not exactly parallel it. At longer reaction times the molecular weights are affected by “back‐biting” degradation.