Abstract: The water absorption property of bio-based resin matrix based on rosin-sourced anhydride was studied under room and 70 ℃ temperature in the environment of distilled water and nature sea water, and also the water absorption course was simulated by Fick model. The water absorption results of AGMP3600 were compared with those of epoxy resin system cured by dicyandiamide. The dynamical mechanic property and micromorphology for both resin before and after water absorption were investigated. The results show that AGMP3600 resin matrix has good water resistant, the quasi equilibrium water absorption rate at 70 ℃ in sea water is 2.01%, the diffusion coefficient is 1.77×10^-6 mm²/s. For AP2300 resin matrix , the quasi equilibrium water absorption rate at 70 ℃ in sea water is 6.60%, and the diffusion coefficient is 0.46×10^-6 mm²/s. With the soak time of casting sample lasting, the storage modulus of AGMP3600 first decreases and then increases, and the glass transition temperature corresponding to the peak value of mechanical loss decreases slightly. On the contrary, for the AP2300 resin matrix, the storage modulus and glass transition temperature are both decrease. From the micro metallographic photographs, the water absorption has little damage on the micropores of AGMP3600. But for AP2300 resin matrix, the water absorption made the number of micropore increasing and the volume enlarged.

Key words: bio-based resin, rosin-sourced anhydride, epoxy resin, water absorption and diffusion, composites