DABCO- and DBU-intercalated α-zirconium phosphate as latent thermal catalysts in the copolymerization of glycidyl phenyl ether (GPE) and hexahydro-4-methylphthalic anhydride (MHHPA)

•The latent catalytic abilities of DABCO- and DBU-intercalated α-ZrP were estimated.•Both intercalation compounds performed well as latent thermal catalysts.•In the case of α-ZrP·DBU the resulting products existed between the interlayers.

The latent catalytic abilities of tertiary amines-intercalated α-zirconium phosphate [(α-ZrP·amine): 1,4-diazabicyclo[2,2,2]octane (α-ZrP·DABCO) and 1,8-diazabicyclo[5,4,0]undec-7-ene (α-ZrP·DBU)] were examined by copolymerization of glycidyl phenyl ether (GPE) and hexahydro-4-methylphthalic anhydride (MHHPA) at varying temperatures for 1 h periods. Polymerization was not observed until the reactants were heated to 100 °C or above. Upon increasing the temperature, the conversion factors of GPE increased such that, at 140 °C, both conversions were over 90% for α-ZrP·DABCO and α-ZrP·DBU. The thermal stabilities of GPE and MHHPA with the catalysts at 40 °C for 144 h were tested: GPE with α-ZrP·DBU achieved conversions of 9%. The reaction in the presence of α-ZrP·DABCO did not proceed at 40 °C for 144 h.

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