Bio-based thermosetting bismaleimide resins using cardany linolenate and allyl cardanyl ether

Cardanyl linolenate (CDLN) and ally! cardanyl ether (ACDE) were synthesized from cardanol (CD) which is one of the inexpensive natural resources. Prepolymerized compounds of CDLN/4,4'-bismaleimidodiphenylmethane (BMI) and ACDE/BMI with the molar ratios of 1/2, 1/2.5 and 1/3 at 200 degrees C were compression-molded at 250 degrees C to produce cured CDLN/BMI and ACDE/BMI resins (cCDLN/BMI and cACDE/BMI), respectively. The.thermal and mechanical properties of cCDLN/BMI and cACDE/BMI were investigated in relation to the difference of reactivity between the linolenate group of CDLN and the allyl group of ACDE. The H-1 NMR and mass spectral analyses of the reaction product of methyl linolenate and N-phenylmaleimide (PMI) revealed that PMI-rich oligomer was produced by the addition copolymerization. FT-IR analyses of cCDIN/BMI and cACDE/BMI revealed that the terminal olefins have a higher reactivity toward the addition copolymerization or ene reaction with maleimide groups than the internal olefins. Although some components which were not incorporated into the polymer networks for cCDLN/BMIs caused a little reduction of storage modulus (E') before the glass transition starts, E's of cACDE/BMIs did not decrease until the glass transition starts at similar to 300 degrees C. The 5% weight loss temperatures (444-453 degrees C) of cACDE/BMIs were higher than those (327-426 degrees C) of cCDLN/BMIs. Also, cACDE/BMIs displayed much better flexural properties than cCDLN/BMIs. The fact that cACDE/BMIs showed better thermal and mechanical properties was attributed to a higher functionality (1.41) of terminal olefins for ACDE than that (0.41) for CDLN. (C) 2015 Elsevier B.V. All rights reserved.