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Ring‐expansion polycondensation of 2‐stanna‐1,3‐dioxepane (or 1,3‐dioxepene) with dicarboxylic acid chlorides
Author(s) -
Kricheldorf Hans R.,
Chatti Saber,
Schwarz Gert
Publication year - 2004
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200450611
Subject(s) - chemistry , polyester , chloride , condensation polymer , diol , polymer chemistry , dicarboxylic acid , heptane , organic chemistry , polymer
2,2‐Dibutyl‐2‐stanna‐1,3‐dioxepane 1 (or 1,3‐dioxepene 2) were prepared from 1,4‐butane (or 1,4‐butene) diol and dibutyltin dimethoxide. They were polycondensed at 80°C in n ‐heptane with adipoyl‐, suberoyl, sabacoyl chloride and with decane‐1,10‐dicarbonyl chloride. In the case of suberoyl chloride and 2,2‐dibutyl‐2‐stanna‐1,3‐dioxepane reaction time, temperature and stoichiometry were varied to optimize both the molecular weight and the fraction of cyclic polyesters. With a slight excess of the dicarboxylic acid chlorides, only macrocyclic polyesters were obtained in all cases. The resulting cyclic polyesters were characterized by viscosity measurements, by 1 H and 13 C NMR and by MALDI‐TOF mass spectrometry.