| Polycarbonate(PC)is an excellent engineering plastic,with excellent impact resistance,mechanical strength,a wide range of temperature application,low creep value and good weather resistance,excellent shape memory performance and other advantages.It has great potential to solve the shortcomings of the satellite flexible solar panel electric drive system,such as cĪ¼mbersome,heavy structure and unreliable system.In this paper,we prepared 1.75 mm diameter wires of PC/ carbon nanotubes(CNTs)/carbon fiber(CF)composites based on FDM printing technology,investigated the effects of CNTs and CF on their electrical conductivity,shape memory and other properties.First of all,starting from the FDM printing parameters,to find the appropriate printing parameters to improve the high temperature polymer PC in the printing process is easy to warpage,easy stratification,mechanical properties can not be guaranteed and other shortcomings,CNTs conductive particles were introduced to increase its mechanical and conductive properties,so as to realize the electric drive remote shape memory effect.Finally,prepared PC/CNTs/CF terpolymer by adding CF,and tested its conductive properties and shape memory properties.Verified the possibility of its application in complicated folding mechanisms by establishing a variety of bionic models.The main research content of this article is as follows:(1)Studied the optimal printing parameters of polycarbonate.Prepared the pure polycarbonate 3D printing silk.Due to the low success rate of polycarbonate printing and poor performance of the sample,Determined the thermal deformation temperature of the material by differential thermal scanning calorimeter(DSC),and established a single factor experimental table by selecting printing speed,printing layer thickness and printing temperature as variables.Studied and analyzed the influences of these variables on the bending strength,tensile strength and interlayer bonding force of the sample through the microscopic characterization,so as to select the optimal printing parameters for the successful follow-up experiments.(2)Explored the 4D printing performance of PC/CNTs.Prepared 1.75 mm printing wires of PC/CNTs composites with carbon nanotube proportions of 1%,2%,3%,5% and 7% for 4D printing performance study.Measured the effects of CNTs addition on Tg by DSC,and tested the effects of CNTs content on the mechanical properties,electrical conductivity and shape memory properties of the samples.Tested the influence of curvature radius on shape memory recovery rate and recovery time of a new U-shaped shape memory sample,and the electrical and thermal conductivity of the composite.(3)Prepared the shape memory folding model of PC/CNTs/CF ternary composite.On the basis of CNTs content of 3%,developed a set of short-cut carbon fiber dispersion process.1%-3% short-cut carbon fiber was added respectively,and the printing wire of PC/CNTs/CF ternary composite was prepared by twin-screw extrusion mechanism,and the mechanical properties,electrical properties,thermal drive and electric drive shape memory properties were carried out.By studying the folding and unfolding modes of flying animals,insects and plants,made and tested a variety of bionic folding and unfolding models,which proved the feasibility of their application in remote actuated folding and unfolding mechanisms. |
