Synthesis and fabrication of biobased thermoplastic polyurethane filament for FDM 3D printing

Abstract

This study describes a soft-actuator grade thermoplastic polyurethane (TPU) with 73 $ 86 shore A, the method of its fabrication and selected properties.The TPU was produced using bio-based synthesized TPU (HP 2.5, HP 3.0, HB 2.5, and HB 3.0) pellets with bio-based polyether-biol (PO3G-1000), and dicyclohexylmethane diisocyanate (H 12 MDI) and bio-based 1,3 propanediol (PDO) and 1,4 butanediol (BDO) as a chain extender. The TPU was formed into a filament for fused deposition modeling (FDM) 3D printers during a melt-extrusion process at 180 $ 220 C. The manufactured TPU filaments were characterized by rheological, chemical, thermal, and mechanical analyses. The equivalence ratio 3.0 with a relatively large amount of HS with BDO as a chain extender, more hydrogen-bonding peaks occurred. The transition temperature and mechanical properties increased depending on the [NCO]:[OH] ratio, and for BDO as the chain extender. However, it was found that when PDO derived from natural material was used, the thermal stability was better. From these results, samples of auxetic re-entrant TPU were printed with the filaments with reference to the melt flow index. The results showed that the biosynthesized HP 3.0 with a hardness of (82 ± 1) shore A was most suitable for FDM 3D printing.

Synthesis of Novel Shape Memory Thermoplastic Polyurethanes (SMTPUs) from Bio-Based Materials for Application in 3D/4D Printing Filaments

“…After extrusion of the TPU filament, an auxetic re-entrant (RE) was printed using the Cubicreator program (Cubicon Inc., Seongnam, Republic of Korea) and a fused deposition modeling (FDM) 3D printer (Cubicon Single Plus, TPC Mechatronics Corp., Incheon, Republic of Korea). In our previous study [ 9 , 34 ], a 3D-printed sinusoidal and auxetic sinusoidal pattern was prepared. In the current study, a RE sample measuring 10 mm × 10 mm, with a repeat size of 30 mm × 30 mm, has been developed.…”

Three-dimensional printed re-entrant strain sensor using various carbon types/thermoplastic polyurethane filaments

“…In addition, during tensile testing, it was confirmed to have elasticity and tensile behavior with a high elongation rate like a typical elastomeric material. [35][36][37][38][39][40][41] In the case of GR-TPU, GR is more difficult to stretch than CB because the overlapped plate-like GR fraction appears during stretching. 52 Electrical property of the three types of carbon/TPU filaments…”

“…In previous studies, we have investigated materials for the fabrication of soft electronic meta-structure sensors via FFF 3D printing, including TPU [35][36][37][38][39] and ready-made carbon/polylactic acid (PLA) material filaments. [39][40][41] In addition, we have investigated the manufacturing of strain sensors by dip-coating castor-oil-based waterborne polyurethane (CWPU) on TPU outputs with an auxetic structure, 42,43 conductive filaments by coating GR on filaments, 44 and compression sensors by coating GR on TPU outputs.…”

“…Hence, CB-TPU exhibits the best effect on TPU. In addition, during tensile testing, it was confirmed to have elasticity and tensile behavior with a high elongation rate like a typical elastomeric material [35][36][37][38][39][40][41]. In the case of GR-TPU, GR is more difficult to stretch than CB because the…”

Study on CNT/TPU cube under the 3D printing conditions of infill patterns and density

“…CNTs composed of six hexagonal graphite sheets connected in a tubular shape exhibit excellent conductivity, mechanical properties, and electrical conductivities. Thermoplastic polyurethane (TPU) is used to impart excellent stretchability and flexibility 25 – 27 . As for the research on manufacturing sensors by synthesizing TPU and carbon nanomaterials, there have been studies on manufacturing sensors with CNT/TPU 28 – 30 , GR/TPU 31 – 34 , and CB/TPU 35 , 36 .…”