4D打印磁响应形状记忆环氧树脂基复合材料制备与性能

Preparation and properties of 4D printed magneto responsive shape memory epoxy resin-based composites

以环氧树脂(EP51)为基体,乙炔炭黑(ACB)和镍粉(Ni)为填料,聚醚多元醇(PPG)为增韧剂共混制成打印墨水,利用直写3D打印机制备ACB-Ni/EP51复合材料。通过流变仪、直写3D打印机对墨水的流变性能和可打印性进行表征;通过拉力实验机(UTM)、扫描电镜(SEM)、动态热机械分析仪(DMA)、差示扫描量热仪(DSC)对材料力学性能、微观形貌、动态力学性能、差热性能和形状记忆效应进行表征,探究了填料含量对墨水和材料性能的影响。结果表明:ACB含量达到12wt%时,墨水具有良好的可打印性;当Ni粉含量达到16wt%时,打印针头堵塞造成打印不连续、不均匀。固化后生成的“海岛”增韧结构使材料拉伸强度明显提高(60 MPa以上)。随着Ni粉含量增加,对拉伸强度的影响由促进变为削弱。当Ni粉含量从6wt%增加至14wt%,形状固定率(R_(f))从99.4%降至94.2%。在300 kHz交变磁场作用下,形状发生回复,Ni粉含量增加使形状回复率(R_(r))和回复速率升高,Rr从94.8%提升至99.1%,回复时间从39 s缩短至17 s。Ni-ACB/EP51复合材料具有较好的形状记忆性能,在空间可展开结构、驱动器及4D打印等方面有一定的应用前景。

ACB-Ni/EP51 composites were prepared by using direct-write 3D printer with ink that was blended from epoxy resin(EP51) as the matrix,acetylene black(ACB) and nickel powder(Ni) as fillers,and polyether polyol(PPG)as toughening agent.Rheological properties and printability of ink were characterized by rheometer and directwrite 3D printer,mechanical properties,microscopic morphology,thermal properties,and shape memory properties of the material were characterized by universal tensile testing machine(UTM),scanning electron microscope(SEM),dynamic thermomechanical analyzer(DMA),and differential scanning calorimeter(DSC).The effects of fillers on properties of the ink and material were investigated.The results show that the ink can be printed well when the ACB content reaches 12wt%.Clogging of the printer nozzle causes discontinuous and uneven printing when Ni content reaches 16wt%.The toughened structure of the "island" formed after solidification significantly improves the tensile strength of the material(above 60 MPa).As Ni content increases,the effect of Ni on tensile strength changes from promoting to weakening.The shape fixation rate(R_(f)) decreases from 99.4% to 94.2% when Ni content increases 6wt% increases to 14wt%.Under the action of a 300 kHz alternating magnetic field,the shape recovery occurs,and an increase in Ni content results in higher shape recovery rate(R_(r)) and recovery rate,Rr increases from 94.8% to 99.1%,and the recovery time shortens from 39 s to 17 s.The ACB-Ni/EP51 composites exhibits excellent shape memory performance and has promising application prospects in areas such as deployable structures in space,actuators,and 4D printing.