Structure-properties relationship of biosourced stereocontrolled polytriazoles from click chemistry step growth polymerization of diazide and dialkyne dianhydrohexitols.

The design of dialkyne and diazide functionalized dianhydrohexitol stereoisomers (1-6) afforded a new family of starch-based polytriazoles (7-15) with defined stereochemistry through A(2) + B(2) CuAAC step growth polymerization. The present strategy gave rise to polytriazoles having a high biosourced weight fraction (superior to 60% wt) and exhibiting relatively high molar masses (M(n) = 8-17 kg/mol) that could be easily dissolved in DMF or DMSO. The obtained materials were amorphous and displayed high transition temperatures (T(g) = 125-166 °C) as well as good resistance to thermal degradation (T(d10) = 325-347 °C). Monomer stereochemistry proved to be a crucial parameter aiming at generating polymers with high T(g). Thus, optimal thermal properties were obtained with monomers having RR absolute configuration of the C-2 and C-5 carbon atoms (isomannide configuration).