Structure property correlations of bioactive composite structures manufactured by injection molding and fused filament fabrication

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Journal Title
Journal ISSN
Volume Title
Kemian tekniikan korkeakoulu | Master's thesis
Date
2020-05-19
Department
Major/Subject
Polymer technology / Biomaterials Science
Mcode
N5T
Degree programme
Nordic Master in Polymer Technology (N5PolTech)
Language
en
Pages
49+11
Series
Abstract
Since 1980s tissue engineering and additive manufacturing have evolved and eventually started to be combined to overcome medical challenges. Alone in the USA there are 7 million orthopedics related surgeries performed yearly. The aim of this project was to investigate two copolymer composites and obtain information about the mechanical properties of the composites when they are printed with FFF technology. Poly(L-lactide-co- D,L-lactide) (PLDLLA) in a 70:30 ratio was combined with 10, 20 and 30 wt% β-tricalcium phosphate (β-TCP). Poly(lactide-co-caprolactone) (PLCL) with a ratio of 70:30 was combined with β-TCP in the same ratios as the PLDLLA. From the injection molded samples the neat PLDLLA had the highest Young’s Modulus of 3.13 MPa and from the 3D printed samples the 20% β -TCP PLDLLA of 3.34 MPa. . It was seen that with increased β- TCP the Young’s Modulus, the elongation break, the stress at break and the toughness decreased for the injection molded specimen. The same decreasing trend was seen for the 3D printed samples, except the Young’s Modulus which increased with more β-TCP. No FFF printing was performed with the PLCL and PLCL-β-TCP composites due to soft filaments that were unable to be fed into the printer. However, the injection molded PLCL composite tensile testing results showed a clear reinforcing effect through addition of β- TCP to the soft and flexible PLCL polymer. Rheological measurements showed similar complex viscosity of around 50 Pa * s at printing temperature for the laboratory made copolymer composites compared to commercial Poly light PLA filament. With β-TCP content increase the complex viscosity for the composite decreased at the desired printing temperature.
Description
Supervisor
Seppälä, Jukka
Thesis advisor
von Bochove, Bas
Dienel, Kasper
Keywords
PLDLLA, PLCL, 3D printing, injection molding, tensile testing, rheology
Other note
Citation