Session: PMSE/POLY Poster Session:

With the ever-increasing problem of plastic waste pollution, efforts have been focused on incorporating dynamic covalent chemistries into thermosets to design reprocessable polyurethanes. Bulky-amide linkages formed through the condensation of sterically hindered secondary amines with isocyanates provide a thermally labile bond. In this work, diamine azole-based blocking agents (DABs) were synthesized with imidazole and triazole diamines. Dynamic networks were prepared by combining azole DAB, Desmodur N3300, and nonanol as a plasticizing chain end. Dynamic network properties and network reprocessing capabilities were characterized using thermal gravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. Thermo-mechanical analyses afforded measurements of T_d, T_g, E, T_v, and M_c. Overall, the re-processable urethanes presented here demonstrated thermal sensitivity relative to azole structure (imidazole > triazole).

Kimberly Pham

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