| With the rapid development of industry and the continuous advancement of computer technology,green environmental protection has become the theme of the times.In the automotive industry,new energy technologies,green materials,and smart cars are the main directions of development.In the green material,fiber-reinforced polymer composites become a major component.The excellent biodegradability of polylactic acid(PLA)has always been the first choice for green materials,while basalt fiber(BF)is also famous for its green environmental protection.Meanwhile,graphene oxide(GO)with good strength is also frequently introduced into fiber reinforced polymer composites.In this paper,polyamic acid is used as a matrix,and basalt fiber is used as a reinforcing material to form a binary material through methods such as condensing and hot pressing,and explore the effect of fiber surface treatment on material properties.The main content of the paper is as follows:A silane coupling agent(KH550)was used as a surface treatment agent to modify the surface of the basalt fiber,and the graphene oxide(GO)obtained by the Hummers method was introduced into the modifier to further improve the surface condition of the basalt fiber.At the same time,the basalt fiber was modified by changing the concentration of KH550,and the microscopic properties of the composite material were tested.The results show that the modification effect is best when the KH550 concentration is 0.85%.In the aspect of crystallization,the addition of graphene oxide promotes the crystallization of the mater ial,and the phenomenon of ‘transcrystallization' occurs in the material,which has a positive guiding effect on the macroscopic mechanical properties of the material.Using modified basalt fiber(KBF,KBF-GO)as reinforcement,the content of basalt fiber was changed to prepare KBF/PLA and KBF-GO/PLA,then prepared as a standard sample by hot pressing to make a series of tests.The results show that the increase of fiber content can improve the mechanical propert of composites.The tensile strength of KBF20/PLA and KBFGO20/PLA materials is 28.9% and 37.2% higher than that of PLA.After the modification,the surface of the basalt fiber becomes rough and a more solid interface is established with the polylactic acid matrix,and at the same time the surface of the rough basalt fiber can adsorb more polylactic acid matrix to form crystals around the fiber,With the addition of graphene oxide(GO),the increase of nucleation sites induces the formation of crystal nucleus and promotes the growth of crystalsin,and thus the " transcrystallization " structure appears in the material to improve the overall performance of the material.A mathematical model was used to simulate the tensile properties of the composites and compared with the experimentally measured values to achieve mutual demonstration between model simulations and experimental data.The simulation results show that the Rom model simulates the tensile strength of the material well and reveals that the fibers are evenly distributed in the matrix.The Halpin-Tsai model and the Tandon-Weng model have better simulation results for the elastic modulus of the composite material.Finally,the Kelly-Tyson model was used to study the interface properties of KBF/PLA and KBF-GO/PLA.The relevant research results in this paper have a certain guiding significance for the subsequent research and development of graphene oxide-basalt fiber/polylactic acid composites. |
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