On the Thermomechanical Behavior of 3D-Printed Specimens of Shape Memory R-PETG
From commercial pellets of recycled polyethylene terephthalate glycol (R-PETG), 1.75 mm diameter filaments for 3D printing were produced. By varying the filament’s deposition direction between 10° and 40° to the transversal axis, parallelepiped specimens were fabricated by additive manufacturing. Wh...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-05-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/15/10/2378 |
| _version_ | 1797598515216515072 |
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| author | Ștefan-Dumitru Sava Nicoleta-Monica Lohan Bogdan Pricop Mihai Popa Nicanor Cimpoeșu Radu-Ioachim Comăneci Leandru-Gheorghe Bujoreanu |
| author_facet | Ștefan-Dumitru Sava Nicoleta-Monica Lohan Bogdan Pricop Mihai Popa Nicanor Cimpoeșu Radu-Ioachim Comăneci Leandru-Gheorghe Bujoreanu |
| author_sort | Ștefan-Dumitru Sava |
| collection | DOAJ |
| description | From commercial pellets of recycled polyethylene terephthalate glycol (R-PETG), 1.75 mm diameter filaments for 3D printing were produced. By varying the filament’s deposition direction between 10° and 40° to the transversal axis, parallelepiped specimens were fabricated by additive manufacturing. When bent at room temperature (RT), both the filaments and the 3D-printed specimens recovered their shape during heating, either without any constraint or while lifting a load over a certain distance. In this way, free-recovery and work-generating shape memory effects (SMEs) were developed. The former could be repeated without any visible fatigue marks for as much as 20 heating (to 90 °C)-RT cooling–bending cycles, while the latter enabled the lifting of loads over 50 times heavier than the active specimens. Tensile static failure tests revealed the superiority of the specimens printed at larger angles over those printed at 10°, since the specimens printed at 40° had tensile failure stresses and strains over 35 MPa and 8.5%, respectively. Scanning electron microscopy (SEM) fractographs displayed the structure of the successively deposited layers and a shredding tendency enhanced by the increase in the deposition angle. Differential scanning calorimetry (DSC) analysis enabled the identification of the glass transition between 67.5 and 77.3 °C, which might explain the occurrence of SMEs in both the filament and 3D-printed specimens. Dynamic mechanical analysis (DMA) emphasized a local increase in storage modulus of 0.87–1.66 GPa that occurred during heating, which might explain the development of work-generating SME in both filament and 3D-printed specimens. These properties recommend 3D-printed parts made of R-PETG as active elements in low-price lightweight actuators operating between RT and 63 °C. |
| first_indexed | 2024-03-11T03:22:12Z |
| format | Article |
| id | doaj.art-3628bccc477f47a3b5fddc4c3a52a68e |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-11T03:22:12Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-3628bccc477f47a3b5fddc4c3a52a68e2023-11-18T02:59:14ZengMDPI AGPolymers2073-43602023-05-011510237810.3390/polym15102378On the Thermomechanical Behavior of 3D-Printed Specimens of Shape Memory R-PETGȘtefan-Dumitru Sava0Nicoleta-Monica Lohan1Bogdan Pricop2Mihai Popa3Nicanor Cimpoeșu4Radu-Ioachim Comăneci5Leandru-Gheorghe Bujoreanu6Faculty of Materials Science, “Gheorghe Asachi” Technical University of Iași, Blvd. Dimitrie Mangeron 71A, 700050 Iasi, RomaniaFaculty of Materials Science, “Gheorghe Asachi” Technical University of Iași, Blvd. Dimitrie Mangeron 71A, 700050 Iasi, RomaniaFaculty of Materials Science, “Gheorghe Asachi” Technical University of Iași, Blvd. Dimitrie Mangeron 71A, 700050 Iasi, RomaniaFaculty of Materials Science, “Gheorghe Asachi” Technical University of Iași, Blvd. Dimitrie Mangeron 71A, 700050 Iasi, RomaniaFaculty of Materials Science, “Gheorghe Asachi” Technical University of Iași, Blvd. Dimitrie Mangeron 71A, 700050 Iasi, RomaniaFaculty of Materials Science, “Gheorghe Asachi” Technical University of Iași, Blvd. Dimitrie Mangeron 71A, 700050 Iasi, RomaniaFaculty of Materials Science, “Gheorghe Asachi” Technical University of Iași, Blvd. Dimitrie Mangeron 71A, 700050 Iasi, RomaniaFrom commercial pellets of recycled polyethylene terephthalate glycol (R-PETG), 1.75 mm diameter filaments for 3D printing were produced. By varying the filament’s deposition direction between 10° and 40° to the transversal axis, parallelepiped specimens were fabricated by additive manufacturing. When bent at room temperature (RT), both the filaments and the 3D-printed specimens recovered their shape during heating, either without any constraint or while lifting a load over a certain distance. In this way, free-recovery and work-generating shape memory effects (SMEs) were developed. The former could be repeated without any visible fatigue marks for as much as 20 heating (to 90 °C)-RT cooling–bending cycles, while the latter enabled the lifting of loads over 50 times heavier than the active specimens. Tensile static failure tests revealed the superiority of the specimens printed at larger angles over those printed at 10°, since the specimens printed at 40° had tensile failure stresses and strains over 35 MPa and 8.5%, respectively. Scanning electron microscopy (SEM) fractographs displayed the structure of the successively deposited layers and a shredding tendency enhanced by the increase in the deposition angle. Differential scanning calorimetry (DSC) analysis enabled the identification of the glass transition between 67.5 and 77.3 °C, which might explain the occurrence of SMEs in both the filament and 3D-printed specimens. Dynamic mechanical analysis (DMA) emphasized a local increase in storage modulus of 0.87–1.66 GPa that occurred during heating, which might explain the development of work-generating SME in both filament and 3D-printed specimens. These properties recommend 3D-printed parts made of R-PETG as active elements in low-price lightweight actuators operating between RT and 63 °C.https://www.mdpi.com/2073-4360/15/10/2378recycled PETG3D printingshape memory effectstorage moduluswork generationfractographs |
| spellingShingle | Ștefan-Dumitru Sava Nicoleta-Monica Lohan Bogdan Pricop Mihai Popa Nicanor Cimpoeșu Radu-Ioachim Comăneci Leandru-Gheorghe Bujoreanu On the Thermomechanical Behavior of 3D-Printed Specimens of Shape Memory R-PETG Polymers recycled PETG 3D printing shape memory effect storage modulus work generation fractographs |
| title | On the Thermomechanical Behavior of 3D-Printed Specimens of Shape Memory R-PETG |
| title_full | On the Thermomechanical Behavior of 3D-Printed Specimens of Shape Memory R-PETG |
| title_fullStr | On the Thermomechanical Behavior of 3D-Printed Specimens of Shape Memory R-PETG |
| title_full_unstemmed | On the Thermomechanical Behavior of 3D-Printed Specimens of Shape Memory R-PETG |
| title_short | On the Thermomechanical Behavior of 3D-Printed Specimens of Shape Memory R-PETG |
| title_sort | on the thermomechanical behavior of 3d printed specimens of shape memory r petg |
| topic | recycled PETG 3D printing shape memory effect storage modulus work generation fractographs |
| url | https://www.mdpi.com/2073-4360/15/10/2378 |
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