(118f) Structural Control of Polybenzoxazine/Epoxy Composites with Dual Crosslinking Network for Corrosion Protection

With the advent of corrosion protection technology, composite coatings have aroused much more attention among the area due to the apparent enhancement on their performance after combing with different components. Polybenzoxazine/epoxy composites were developed recently as a novel coating material for corrosion protection. The reaction between the phenolic –OH groups of the ring-opened benzoxazine and epoxide groups in epoxy can effectively increase the cross-link density of the composite matrix and improve coatings’ corrosion resistance by strengthening their barrier ability against corrosive medium, which has been confirmed by our previous work¹. The polybenzoxazine/Epoxy composite coating with dual crosslinking network exhibit a good corrosion protection improvement, a reduction of one decade on corrosion rate was observed by the incorporation of Epoxy into polybenzoxazine matrix, as well as a good hydrophobic ability with a water contact angle of 100° even after the corrosion test, which could be a fascinating characteristic for the anticorrosion application. The dual crosslinking network structure is believed to be a vital part of the coatings’ performance.

Therefore, mono-, bi-, and trifunctional benzoxazine monomers are designed and synthesized in this work. Composite coatings based on these benzoxazines are prepared by combining with epoxy in order to fabricate coatings with controllable cross-link density. Thus, the relationship between coatings’ crosslinking structure and performance for corrosion protection could be investigated thoroughly. The reaction between two components was characterized by Fourier transform infrared spectroscopy. The effects of composites’ structure on the corrosion resistance of coated aluminum were investigated by open circuit potential and electrochemical impedance spectroscopy, respectively. Molecule stimulation was performed to calculate the cross-link density of different samples. The results of this work could provide guidance for the design of high-performance polybenzoxazine-based coatings used for corrosion protection.

Changlu Zhou, E-mail: changluzhou@ecust.edu.cn

*Correspondence Zhong Xin, Professor, Tel.: +86 21 64240862; Fax: +86 21 64251772, E-mail: xzh@ecust.edu.cn

1. Zhou C, Lin J, Lu X, et al. Enhanced corrosion resistance of polybenzoxazine coatings by epoxy incorporation.RSC Advances. 2016, 6(34): 28428-28434