Highly Tunable Thermal Properties of Multifunctional Thiol‐Ene Networks Derived From Sugar‐Based Monomers

ABSTRACT Multifunctional sugar monomers offer a variety of structural scaffolds for the formation of thiol‐ene networks. Eleven allylated sugars, each having a nominal number of functionalities ranging from 4 to 11, were combined with seven dithiols that were structurally different to produce 77 thiol‐ene networks. Network formation was assessed by ATR‐FTIR, gel‐fraction, and swelling measurements, whereas the thermal and dynamic mechanical analyses indicated that the glass‐transition temperatures T g were in the range from −45°C to 53°C, the midpoint degradation temperatures were between 277°C and 378°C, and the rubbery storage moduli at 100°C were between 3 and 155 MPa. The sugar scaffolds with higher‐functionality generally increased the ranges of the rubbery modulus, the DMA‐derived apparent elastic‐strand density, T g , and relaxation breadth, although the extent of these effects depended strongly on the structure of the dithiol. Analysis based on composition demonstrated that the T g ‐ v c ,app relationship differed in the various dithiol series rather than following a general high‐density plateau. Examination of E ′, E ″, and tan delta showed that there were composition‐dependent differences in relaxation breadth. The sugar and the dithiol structure provide complementary structural parameters for adjusting the thermal and thermomechanical response of multifunctional sugar‐derived thiol‐ene networks.