3D-Printed Polyester-Based Prototypes for Cosmetic Applications—Future Directions at the Forensic Engineering of Advanced Polymeric Materials

Abstract

Knowledge of degradation and impairment phenomena of (bio)degradable polymeric materials under operating conditions, and thus the selection of test procedures and prediction of their behavior designates the scope and capabilities as well as possible limitations of both: the preparation of the final product and its durability. The main novelty and objective of this research was to determine the degradation pathways during testing of polylactide and polylactide/polyhydroxyalkanoate materials made with three-dimensional printing and the development of a new strategy for the comprehensive characterization of such complex systems including behavior during waste disposal. Prototype objects were subjected to tests for damage evolution performed under simulating operating conditions. The reference samples and the tested items were characterized by gel permeation chromatography and differential scanning calorimetry to determine changes in material properties. The studies showed that: polyhydroxyalkanoate component during accelerated aging and degradation in environments rich in microorganisms accelerated the degradation of the material; paraffin accelerates polylactide degradation and slows degradation of polyhydroxyalkanoate-based material; under the influence of an environment rich in enzymes, paraffin contamination accelerates biodegradation; under the influence of natural conditions, paraffin contamination slowed degradation; the processing conditions, in particular the printing orientation of individual parts of the container, influenced the material properties in its various regions, affecting the rate of degradation of individual parts.

Three-Dimensional Printed PLA and PLA/PHA Dumbbell-Shaped Specimens: Material Defects and Their Impact on Degradation Behavior

“…Then, on the DSC curve of PLA/PHA dumbbell-shaped specimens before degradation, a cold crystallization (Tcc) with a lower temperature for horizontal processing build direction was observed (Table 2, Figure 4), confirming the earlier findings regarding the impact of the printing direction on the crystallization [4,24] and a melting endotherm with maximum temperature around 153 ± 1 °C for PLA and 172 ± 1 °C for PHA component of the blend. Since PHA similarly promotes crystallization as the nucleating agent [4,24], for PLA/PHA dumbbell-shaped specimens, enthalpy of cold crystallization (ΔHcc) was visible. During the second heating run, the PLA dumbbell-shaped specimens (previously melted and then cooled) did not exhibit a melting effect.…”

“…Enthalpic relaxation is a parameter that characterizes the phenomenon of physical aging, during which the movements of some fragments/groups of molecules in the examined material vanish [20][21][22][23]. Then, on the DSC curve of PLA/PHA dumbbell-shaped specimens before degradation, a cold crystallization (Tcc) with a lower temperature for horizontal processing build direction was observed (Table 2, Figure 4), confirming the earlier findings regarding the impact of the printing direction on the crystallization [4,24] and a melting endotherm with maximum temperature around 153 ± 1 °C for PLA and 172 ± 1 °C for PHA component of the blend. Since PHA similarly promotes crystallization as the nucleating agent [4,24], for PLA/PHA dumbbell-shaped specimens, enthalpy of cold crystallization (ΔHcc) was visible.…”

“…It was originally found that the processing conditions, in particular, the contact time of the polymer material with the printer working platform, lead to an increase in the crystalline phase of the polymer during printing [4,15,24]. The current publication describes unexpected shrinkage phenomena after post-processing heat treatment observed during a standard degradation study of PLA and PLA/PHA dumbbell-shaped specimens in the degradation series after a period of 70 days, which represents about 50% of the length of the specimens.…”

Industrial composting as a waste management method of polyester materials obtained from renewable sources

“…Podobną metodologię badawczą zastosowano w wypadku badania procesu kompostowania prototypowych opakowań wytworzonych metodą termoformowania (tacki do żywności) oraz druku 3D (słoiki z przeznaczeniem na opakowania kosmetyków) [22,23].…”

“…Podobne wnioski sformułowano na podstawie wyników badań biodegradacji kształtek wykonanych z kilkakrotnie przetworzonego PLA [11,14]. Kolejny obiekt badań stanowiły prototypowe pojemniki z przeznaczeniem na opakowania kosmetyków [23]. Badano prototypowe opakowania wykonane techniką druku 3D z komercyjnego filamentu PLA i PLA/PHA (12% w PHA).…”