Preparation and Properties of 3-Methylcatechol/Furfurylamine Based Polybenzoxazine

3-Methylcatechol/furfurylamine benzoxazine(M-f) containing phenolic hydroxyl group was synthesized to develop a benzoxazine that could be cured at relatively low temperature. The peak exothermic temperature(T-p) of M-f measured by differential scanning calorimetry(DSC) is 172 degrees C, while the T-p of meta-cresol/furfurylamine benzoxazine(MC-f) is 244 degrees C, indicating that the introduction of phenolic hydroxyl groups is beneficial to reduce the ring-opening curing temperature of benzoxazine. The curing kinetics of the two benzoxazine monomers were studied by non-isothermal DSC methods. The calculation results of Kissinger method and Ozawa method both indicated that the apparent activation energy of M-f was lower than that of MC-f. In addition, the adhesion performance of polybenzoxazine to metal substrate was explored by lap shear strength testing. The testing results demonstrated that the lap shear strengths of the M-f polymer to the aluminum and mild steel substrates reached 2.53 MPa and 3.09 MPa, respectively, which were higher than those of the MC-f polymer.

Automated summary

The study showed that the benzoxazine M-f containing phenolic hydroxyl groups has lower curing activation energy and lower ring-opening temperature, leading to better adhesion performance to metal substrates.