Structure-properties relationships in isosorbide-based polyacetals: Influence of linear or cyclic architecture on polymer physicochemical properties

A linear biobased polyacetal was prepared from the reaction between isosorbide and methylene chloride according a one step procedure. Cyclic polyacetal was obtained using the previous linear polymer as precursor. The respective architectures of both polymers and their chemical compositions were carefully established using H-1 NMR and MALDI-TOF spectroscopies. Their molecular weight characteristics were defined using a triple detection size exclusion chromatography while their thermal characteristics were investigated by the conduction of calorimetric and thermogravimetric experiments. The registering of the thermomechanical properties of each kind of isosorbide-based polyacetal showed that the cyclic polymer was the only one able to show a rubbery plateau. This peculiarity was justified by calculation of the threshold value above which entanglements were possible.