Polyurethanes based on isophorone diisocyanate trimer and polypropylene glycol crosslinked by thermal reversible diels alder reactions

Abstract

Crosslinked self-healing polyurethanes based on Diels-Alder (DA) reaction were synthesized from a trifunctionalized isophorone diisocyanate (IPDI) and polypropyleneglycol prepolymer with furfuryl alcohol and a commercial bismaleimide. The DA reaction was followed by FTIR spectroscopy at different temperatures. From the infrared results the kinetic rate constants as well as the DA reaction reversibility were established. The retro DA reaction (rDA) and its reversibility was monitored by DSC according to the enthalpy involved in the process. The obtained polymers exhibited thermosetting properties at room temperature, although they showed thermoplastic behavior at high temperatures.

Self‐healing semi‐IPN materials from epoxy resin by solvent‐free furan–maleimide Diels–Alder polymerization

“…Thermal reversibility in DA reaction takes places by rDA reaction which occurs at various temperatures and depends on the structure of diene/dienophile couples . DA reaction has been used in many polymers such as epoxies, polyacrylates, polyamides, and polyurethanes which rDA dissociation triggered by heat as external stimuli in high temperature (>100 °C) and the structure rebuild in low temperature (<100 °C) . In the rDA temperature range, most polymers are thermally stable and there is no degradation in the polymer structure and polymerization/depolymerization could repeatedly occur with negligible degradation …”

Glass‐transition temperature governs the thermal decrosslinking behavior of Diels–Alder crosslinked polymethacrylate networks

“…As with the signal maxima, no clear trend exists across the series, suggesting further that the polymer T g is not significantly affecting the thermochemistry of the rDA reaction, and that the different decrosslinking temperatures observed by DMA are arising from network effects rather than different rDA onsets. While a few similar DSC treatments of DA networks exist, enthalpies naturally vary widely due to differences in polymer morphologies, density of DA functionalities, and DA electronics.…”

Recyclable Telechelic Cross-Linked Polybutadiene Based on Reversible Diels–Alder Chemistry

“…To further confirm the furan moieties degradation, curves of 9 000 g.mol -1 intermediate series were compared and the weight loss only appeared for Fur2-9k-PB-Fur2 and Net1-9k-PB with an equivalent weight loss (Figure 4e). [37][38][39] DMA analysis was further performed in tensile mode in order to evaluate the properties of the that shorter is the chain length of the precursor, higher is the value of the rubbery plateau (Figure 5a). For instance, the modulus at 25 °C increased from 1.4 MPa to 11.4 MPa for Net1-of the network formed by the shortest chains.…”