Page 22 - eBook_Proceedings of the International Conference on Digital Manufacturing V1

Proceedings of the International Conference on Digital Manufacturing –
Volume 1

Sequence Reagent Amount
7 Sodium sulphate (Na2SO4) 0.072g
Tris(hydroxymethyl)aminomethane
8 6.118g
(TRIS)
9 Hydrochloric acid (HCl) 0-5.000g

Degradation Assessment

The degradation behaviour of the 3D-printed PLA samples was
assessed by monitoring changes in mass over a 28-day immersion
period in SBF. Prior to immersion, all samples were individually
weighed using an analytical balance with a precision of 0.1 mg to
obtain their initial dry weight (W0). Each sample was then fully
immersed in SBF with a concentration of 10 mg/mL in sealed
containers and placed in an incubator maintained at 37°C to
simulate physiological conditions.

At predetermined time intervals (7, 14, 21 and 28 days),
samples were carefully removed from the SBF, gently dried to
eliminate surface moisture and reweighed to obtain the final dry
weight (Wt). The percentage of weight loss (ΔW%) was calculated
using Equation (1):

−
∆ %= × 100 (1)

This gravimetric method allows for quantitative evaluation of
the material's degradation behaviour over time. All measurements
were performed in triplicate to ensure reproducibility and
statistical reliability.

pH Measurement

The pH value of the SBF solution was monitored throughout the
28-day degradation period to evaluate the influence of PLA
degradation on the surrounding environment. pH measurements
were conducted at each predetermined time point (day 7, 14, 21
and 28) using a calibrated digital pH meter with an accuracy of
±0.01. Prior to each measurement, the pH meter was calibrated

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