Composite Basalt & Polyurea Fiber as A Reinforced Skeleton to Enhance the Wear-corrosion Performance of Water Epoxy Coating
As an important supporting structure in wind power equipment,the tower plays a key role in supporting the continuous work of the motor and blades.However,the security risks,maintenance and renewal costs of the tower surface can increase sharply because of corrosion and wear.Organic coatings have been regarded as the most economical and convenient means by which to protect towers from corrosion.Among various coatings,waterborne epoxy resin coating is widely used because it is inexpensive and environmentally friendly.However,micropores and microcracks are usually generated due to the solvent evaporation process,which presents both a path for corrosion medium diffusion and a source of crack initiation and propagation.To address the above issue,various fillers have been introduced into waterborne epoxy resin coating to enhance its comprehensive properties.Among fibrous materials,basalt fiber has several excellent physical and chemical properties,such as excellent chemical stability,radiation resistance,mechanical properties,and low cost.Moreover,its preparation process is less harmful to the environment,and it is a veritable green material.However,adding basalt fibers into epoxy resin coating could lead to the formation of microdefects at the interface between the fibers and the coating due to their large size.Therefore,it is necessary to regulate the surface state of basalt fiber to resolve the incompatibility between the basalt fiber and coating.Hence,in this work,composite fibers(PU@BF)were prepared via in-situ polymer growth technology on the surface of basalt fibers by utilizing the structural and property advantages of polyurea nanofibers(PU)and basalt fibers(BF).Then,PU@BF was introduced into waterborne epoxy resin coating(EP)to prepare a fiber-based composite coating,and the tribological properties and corrosion resistance performance were investigated in depth.The scanning electron microscope results indicated that basalt fibers were uniformly covered by polyurea.The storage modulus values of all composite coatings showed a decreasing trend with increasing temperature,as increasing temperature leads to the accelerated movement of chemical bond chain segments as well as polymer segments.Hence,the coating gradually transitions from a highly elastic state to a viscous state.The storage moduli of EP,PU,BF,and PU@BF at 40 ℃ were 1 445,1 460,1 688,and 1 526 MPa,respectively,indicating that the mechanical performance of the composite coating was improved via the introduction of fibers.The friction factor of PU@BF was kept between 0.1-0.2,whereas that of EP was approximately 0.8,demonstrating that the introduced composite fibers had a great antifriction effect.The wear rate of PU@BF was 1.2×10-5 mm3/(N·m),which was decreased by about 78％compared with that of EP(5.5 × 10-5 mm3/(N·m)).The Rc value of PU@BF was 2.5 MΩ·cm2,whereas that of EP was 0.08 MΩ cm2,indicating that PU@BF displayed better anticorrosion performance.Neutral salt spray test results showed that black-gray corrosive pitting was observed on the surface of an Al substrate only after 1 week of test,and the corrosion degree was increased after 3 weeks.However,the surface of an Al substrate of PU@BF was still bright and clean without corrosion,indicating that PU@BF had excellent protection performance.The enhanced antiwear/corrosion performance of PU@BF could be attributed to two reasons.First,the polyurea on the surface of the basalt fiber could reduce the microdefects between basalt fibers and epoxy resin to enhance the interfacial adhesion with epoxy molecules and thereby delay the diffusion of corrosion media during immersion.Second,the surface composite fiber layer can bear the vertical pressure and radial cutting force of the friction pair when the composite is subjected to a reciprocating force,and the inner composite fibers can reduce the deformation of the epoxy by exerting a pinning effect and thereby restricting the initiation and propagation of microcracks during friction.This research verifies the feasibility of a fiber/epoxy composite system to solve the"wear and corrosion"problem of waterborne epoxy coating.The results lay a foundation for the further optimization of the fiber/epoxy composite coating preparation process by exploring the influence law of the fiber orientation distribution on the comprehensive performance of a composite coating and its strengthening mechanism.
万方数据
维普
