不同增强粒子对PLA/TPU复合线材力学性能的影响

Effect of Different Reinforcing Particles on the Mechanical Properties of PLA/TPU Composite Filaments

聚乳酸(PLA)因具有优异的生物相容性而备受关注,但其制品脆性大、韧性不佳,应用范围受限.本文分别以还原氧化石墨烯(rGO)、纳米SiO_(2)和rGO-SiO_(2)作为增强粒子制备了rGO/TPU/PLA、SiO_(2)/TPU/PLA、rGO-SiO_(2)/TPU/PLA等3种复合线材,研究FDM成型件力学性能变化规律,探究不同粒子的增强增韧机理.研究结果表明:当rGO的加入质量分数控制在3%以下时,拉伸强度会有所增加,当超过3%时,因石墨烯局部团聚导致其韧性明显下降;纳米SiO_(2)的加入改善了PLA与TPU界面结合性,使得韧性大幅度增加,而拉伸强度略有增加;与单一增强粒子相比,SiO_(2)和rGO结合在一起改善了其在基体中的分散效果,rGO-SiO_(2)杂化粒子的增强增韧效果更佳,FDM成型件的抗拉强度、韧性均得到了明显提升.

Polylactic acid(PLA)has attracted much attention because of its excellent biocompatibility,however,its products are brittle and poor in toughness,which limits its application range.In this paper,three composite filaments of rGO/TPU/PLA,SiO_(2)/TPU/PLA,and rGO-SiO_(2)/TPU/PLA are prepared by using reduced graphene oxide(rGO),nano-SiO_(2) and rGO-SiO_(2) as reinforcing particles.Meanwhile,the changes in the mechanical properties of fused deposition molding(FDM)formed samples are studied,and the mechanism of strengthening and toughening of different particles is explored.The results show that the tensile strength of the composite sample increases as the amount of rGO added is controlled below 3%.Moreover,the toughness of the composite sample decreases significantly due to the local agglomeration of graphene;The addition of nano-SiO_(2) improves the bonding performance of PLA and TPU interface,which greatly increases the toughness of the sample.However the increase in tensile strength is not obvious.The combination of SiO_(2) and rGO improves the dispersion effect of the filler in the matrix compared with a single reinforcing particle.The rGO-SiO_(2) hybrid particle has a better reinforcing and toughening effect,and the tensile strength and toughness of FDM molded parts are significantly improved.