林业工程学报2025，Vol.10Issue(3)：114-121,8.DOI:10.13360/j.issn.2096-1359.202405009
腰果酚基苯并噁嗪改性环氧树脂及其防腐性能
Preparation of cardanol-based benzoxazine-modified epoxy resin and its anti-corrosion performance
摘要
Abstract
The development of epoxy resin for long-term anti-corrosion coatings is limited due to its low water resistance,poor toughness,and reduced adhesion after long-term service.The hydroxyl group of benzoxazine resin after polymerization can undergo polymerization reaction with epoxy groups,making benzoxazine resin a curing agent for epoxy resin to improve its chemical properties.Anti-corrosion coatings are mainly prepared relying on non-renewable petrochemical resources.With the depletion and increasing consumption of petrochemical resources,the development of sustainable anti-corrosion coatings by replacing or partially substituting petrochemical materials with biomass resources has become a growing trend.Cardanol,a byproduct derived from cashew shell liquid,is an ideal feed stock for preparing epoxy resin and benzoxazine due to its double bonds and phenolic hydroxyl structure.In this work,cardanol-based epoxy resin(CEP)and cardanol-based benzoxazine resin(CBOZ)were synthesized using cardanol as the raw material.CBOZ was prepared by Mannich reaction with paraformaldehyde and aminopropyltriethoxysilane.CEP was synthesized by the esterification of cardanol and butanedionyl chloride with the subsequent oxidation of double bonds by hydrogen peroxide.The anti-corrosion coatings were fabricated by mixing the CBOZ and CEP resins in proportion.The effects of the molar ratio of the epoxy groups to the oxazine ring on the properties of the coatings,such as the thermal performance,the cross-linking density,the film properties,and the wettability,were investigated.The results indicated that the thermal stability and the wettability of CEPBOZ coating increased with the increase of CBOZ content.The coating(CEPBOZ-3)had the best comprehensive performance when the molar ratio of the epoxy groups to the oxazine ring was 1∶1.The CEPBOZ-3 coating had a gel content of 92.49%,a pencil hardness of 5H,an adhesion level of 3,a flexibility of 2 mm,and a water contact angle(WCA)of(107.4±1.3)°.In addition,the coating also exhibited excellent thermal stability with the maximum thermal decomposition temperature(Tp)higher than 470℃and great solvent resistance by resisting wiping with ethanol,toluene,acetone,tetrahydrofuran,and ethyl acetate at least 200 times without any surface changes.Electrochemical impedance spectroscopy tests were conducted on the CEPBOZ-3 coating to evaluate its performance.The developed coating showed good anti-corrosion performance,with an impedance modulus(l Zl0.01Hz)of 1.1×108 Ω·cm2 at low frequencies and 1.0×106 Ω·cm2 at l Zl0.01Hz after 336 h of immersion,indicating that the coating has a long-term anti-corrosion property.This work provides a facile fabrication approach of bio-based composite coatings with durable anti-corrosion performance,demonstrating potential for industrial applications.关键词
腰果酚/环氧树脂/苯并噁嗪/疏水性/防腐涂层Key words
cardanol/epoxy resin/benzoxazine/hydrophobicity/anti-corrosion coating分类
化学化工引用本文复制引用
于金尼,尚倩倩,张猛,周永红..腰果酚基苯并噁嗪改性环氧树脂及其防腐性能[J].林业工程学报,2025,10(3):114-121,8.基金项目
中央级公益性科研院所基本科研业务费专项资金(CAFYBB2022XB001) （CAFYBB2022XB001）
江苏省生物质能源与材料重点实验室(JSBEM-S-202301). （JSBEM-S-202301）
