| 摘要 |
The present invention refers to a process for producing a polycarbonate diol, triol or polyol with increased molecular weight. The process comprises transesterification between a diol, triol or polyol and a carbon dioxide source in the presence of a transesterification catalyst, evaporation of formed alcohol by for instance distillation, polymerisation and further polymerisation by addition of an oligocarbonate diol, triol or polyol, whereby a polycarbonate diol, triol or polyol with an average molecular weight of at least 1000 g/mol is obtained, hi a further aspect, the use of a polycarbonate diol, triol or polyol obtained by the process as a building block in thermoplastic polyesters and polyurethanes is disclosed. |
