Preparation And Corrosion Behavior Of Glass Fiber/Vinyl Ester Resin Composites

Limestone-wet desulfurization process is universal for most coal-fired firepower generator sets in China.However,the flue gas after desulfurization will encounter condensation during the ascending process,and the acid solution will adhere to the lining of the chimney.For a long time,the inner cylinder of the chimney is very corroded.In this paper,the following work is carried out on how to improve the corrosion resistance of the lining while reducing the cost:First,optimizing the VARTM technology.Taking the Vinyl ester resin as the substrate and VARTM technology to prepare resin matrix composites with excellent corrosion resistance.An integrated molding equipment was designed to improve the quality of the workpiece and overcome the shortcoming of low fiber volume content on the basis of the original VARTM process,meanwhile,the fiber volume content is at the rang of 52?58%.As a result,molding quality is excellent evaluated by SEM and nondestructive testing.Second,studying the performance variation rules of fiberglass vinyl ester composites in practical service environment.The composites were conducted accelerated aging experiment scoured by simulate natural rainfall in neutral salt mist aging test box,every 24 h alternant spraying salt mist and drying experiment were designed to corrode the samples.Indicating that the weight gain rate of composites increases with the increase of salt spray days,and the smaller the sample volume,the greater the rate of mass5 change.Compared the non-corrosive composites,the mechanical properties of the composites increased and then decreased after 4 days,14 days,28 days and 60 days salt mist corrosion,accompanying the tensile strength rose by 4.85%,3.18%,4.6%and 5.6%,respectively.Meanwhile,bending strength promoted by 6.57%,1.80%and dropped 4.26%,12.71%;At the same time,Interlayer shear strength went up by 1.32%and fell 5.54%,6.57%,13.61%.Microscopic morphological characterizations revealed the defects formed by diffusion of water molecules resulting collapse of mechanical properties,and causing swell and cracking in the resin matrix further.Third,excavating the corrosion and aging law of glass fiber vinyl ester composites in different acidic environments.Simulating more actual service condition,the composites were carried out accelerated aging experiment to obtain acid corrosion,immersed in 60%sulfuric acid solution,Aqua regia,normal temperature three-acid mixed solution and 60? mixed solution for 4 days,14 days,28 days,60 days,respectively,the bending strength decreased by 60%,13.58%,45.33%and 19.44%.The microscopic morphology of the sample soaked in the three acids mixed solution at 60? water bath has the most reference significance.After 60 days,a large amount of fiber resin debris appeared on the surface of the sample.The main reason for the decrease of mechanical properties is that voids and pores appear between the fiber bundles,and the stress distribution at the fiber-resin interface is uneven,which causes the matrix to crack and the mechanical properties of the composite interface to decrease,resulting in a decrease in bending strength.Through the research in this paper,more substantial lining composites of thermal power chimney and preparation technology were explored.Otherwise,providing valuable reference for practical application by simulating more actual service environment to detect the properties of fiberglass vinyl ester composites.