Additive effects on curing ester-based degradable polyurethane adhesives

This is the abstract of an oral presentation in EBC-VIII, given on June 14, 2022

Faster degradation rates of adhesives under environmental conditions could significantly accelerate
bioremediation processes of glued items. Ester-based polyurethanes (PUR) are more submissive to
hydrolysis and enzymatic degradation than traditionally used polyether PUR. However, adhesives from
ester-based PUR are not widely used, partly due to kinetic uncertainties during their polymerization. In
this investigation, caprolactone and adipate macrodiols were reacted with difunctional and trifunctional
isocyanates, monitoring their polymerization rates by titration, FTIR and viscometry. Temperatures and
molar ratios were also varied, leading to unexpected changes in the course of the polymerization.
Inclusion of caprolactam, acetate and several other additives affected the curing rates significantly. Better
understanding of polymerization kinetics could accelerate the replacement of polyether PUR adhesives
with the ester-based ones, which would improve bioremediation efforts of glued waste items.