生物基环氧/多巴胺改性黏土复合涂层的制备及性能研究

Preparation and Properties of Bio-based Epoxy/Dopamine-modified Clay Composite Coatings

通过盐酸多巴胺和黏土层间的离子交换反应制备了具有反应活性的多巴胺改性黏土(D-黏土),进而采用“淤浆复合法”,将D-黏土以无规剥离形式分散于环氧树脂基体中,与固化剂反应得到腰果酚环氧树脂/D-黏土纳米复合涂层。通过X射线光电子能谱仪(XPS)、傅立叶变换红外光谱仪(FT-IR)和X射线衍射仪(XRD)测试验证了盐酸多巴胺成功嵌入在黏土片层中;研究分析了复合涂层的结构和性能。结果表明:采用盐酸多巴胺成功修饰得到了D-黏土,黏土片层间距由12.5?扩大至74.8?;由于盐酸多巴胺中的酚羟基能在黏土片层与环氧树脂基体间形成氢键,因而能构建较强的有机无机界面作用力,从而有效提升复合涂层的耐热性和力学性能;当D-黏土的含量为2%时,复合涂层的拉伸强度由0.60 MPa增加至1.49 MPa,断裂伸长率由41.79%提升到92.57%,杨氏模量由13.76 MPa提升至70.50 MPa,力学性能最佳。

The reactive dopamine-modified clay(D-clay) was prepared by the ion exchange reaction between dopamine hydrochloride and the clay layer,the D-clay was dispersed in the cardanol-based matrix with the form of random exfoliation,and reacted with curing agent to obtain the cardanol-based epoxy/D-clay nanocomposite coating through "slurry composite method". The successful intercalation of dopamine hydrochloride in the clay platelets was verified by X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FT-IR)and X-ray diffractometer(XRD)tests. The structure and properties of the composite coating were also analyzed. The results showed that the clay was successfully modified by dopamine hydrochloride to obtain D-clay,and the interlamellar spacing was enlarged from 12. 5 ? to 74. 8 ?. Since the phenolic hydroxyl groups in dopamine hydrochloride could form hydrogen bonds between the clay sheet and the epoxy matrix,it can build a strong organic-inorganic interface force,thereby the heat resistance and mechanical properties of the composite coating were effectively improved. When the content of D-clay was2%,the tensile strength of the composite coating increased from 0. 60 MPa to 1. 49 MPa,the elongation at break increased from 41. 79% to 92. 57%,and the Young’s modulus increased from 13. 76 MPa to 70. 50 MPa,the composite coating indicated excellent physical properties.