Page 21 - eBook_Proceedings of the International Conference on Digital Manufacturing V1

Degradation Analysis of 3D Printed PLA in Simulated Body

a nozzle temperature of 210°C and a heated bed temperature of
60°C. A 0.4 mm nozzle was used throughout the process. All
samples were fabricated using a Creality Ender 3 Pro FDM 3D
printer. After printing, the samples were allowed to cool at room
temperature (26℃) and then stored in a desiccator for 24 hours to
stabilise them before degradation testing.

SBF was prepared to replicate the ion concentrations found in
human blood plasma, enabling in vitro evaluation of the
degradation behaviour of PLA in a physiological environment.
The preparation followed the protocol established by Kokubo and
Takadama (Kokubo & Takadama, 2006), using analytical-grade
reagents and deionised water. The list of reagents used is shown
in Table 1 and they were added sequentially under constant
stirring at room temperature (26°C).
Tris(hydroxymethyl)aminomethane (TRIS) was used to buffer the
solution and the pH was adjusted to 7.4 ± 0.01 at 37°C using 1 M
hydrochloric acid (HCl).

The solution was prepared in a clean environment to avoid
contamination and was stored in sealed polyethylene containers at
37°C in an incubator to maintain physiological conditions
throughout the immersion period. The prepared SBF was used in
all degradation experiments, with the solution being refreshed
every seven (7) days to ensure stable ionic strength and to prevent
pH drift caused by PLA hydrolysis.

Table 1: Reagent for SBF solution (Kokubo & Takadama, 2006).

Sequence Reagent Amount
1 Sodium chloride (NaCl) 8.035g
2 Sodium hydrogen carbonate (NaHCO3) 0.355g
3 Potassium chloride (KCl) 0.225g
Di-potassium hydrogen phosphate
4 0.231g
trihydrate (K2HPO43H2O)
Magnesium chloride hexahydrate
5 0.311g
(MgCl2.6H2O)
6 Calcium chloride (CaCl2) 0.292g

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