Influence of UV Ageing on Properties of Printed PLA Containing Graphene Nanopowder

Abstract

The present paper analyses the properties of printed polylactic acid (PLA) samples with admixtures of graphene nanopowder (GNP) at wt. 1%, 2% and 4%. The pure polylactide and admixed polylactide printed samples were examined to determine their chemical-physical properties, stiffness, and strength parameters. The tests of tensile, dynamic mechanical analysis (DMA), difference thermogravimetric (TG), and differential scanning calorimetry (DSC) were executed before and after UV (ultraviolet) treatment. The first part of the paper shows the process of manufacturing granulates and filaments mixed with graphene. The second part of the paper concerns the results of the tests made on printed samples. The analysed samples were printed using a Prusa i3 MK3 printer. It transpired that the content of graphene at 1% improved the mechanical parameters of the printed composite by organising its structure. Increasing the amount of graphene caused the values of the measured parameters to drop. This research indicates how important it is to determine the optimal values of nanoadditives in biopolymers.

Aging Process of Biocomposites with the PLA Matrix Modified with Different Types of Cellulose

“…Samples were placed in a special chamber constructed by our team with an Hg UV-C 11 V lamp, horizontally at 90° to the UV radiation. Samples were placed on a very thin support made from aluminum; additionally, the chamber walls and bottom were lined with an aluminum mirror in such a way that the UV radiation had access to the samples from all sides and from the bottom [ 16 ]. Air circulation was forced to prevent the formation of ozone, which can accelerate the degradation of PLA, from oxygen by UV irradiation.…”

“…PLA, like most polymers, is sensitive to UV irradiation, which decreases its lifespan [ 16 ]. PLA degrades due to the intervention of weathering factors (water, UV irradiation) [ 6 , 17 ], and the degradation time depends on the degree of crystallinity [ 11 ].…”

Recent advancements in biomedical application of polylactic acid/graphene nanocomposites: An overview

“…The inclusion of graphene can affect the biodegradability of PLA. The production methods and chemicals used to prepare graphene and PLA/graphene composites may have adverse environmental effects that need to be considered [55] …”

“…The production methods and chemicals used to prepare graphene and PLA/graphene composites may have adverse environmental effects that need to be considered. [55] Further research is required to fully understand the toxicity, long-term effects, and environmental risks associated with PLA/graphene nanocomposites. However, current studies indicate the need for safety measures when handling these composites, considering the potential health risks from inhalation or long-term exposure, and exploring more sustainable alternatives.…”

Biocompatible Composite Filaments Printable by Fused Deposition Modelling Technique: Selection of Tuning Parameters by Influence of Biogenic Hydroxyapatite and Graphene Nanoplatelets Ratios

“…While some studies have shown that graphene-reinforced PLA poses poor mechanical properties, others have reported that by changing the raster orientation or using larger nanoplatelets, its capabilities may be improved [ 2 ]. Similarly, researchers have investigated the benefits of integrating essential oils or chemically prepared agents for enhancing the dispersion degree for both PLA/GNP [ 12 , 44 ] and PLA/GNP/HA mixtures [ 34 ]. These studies reported that even though the proportion of GNP was reduced to 1–4 wt.% for PLA/GNP and to 0.01–0.1 wt.% for the PLA/GNP/HA samples, the improvements in the mechanical behaviour were signalled only at the lowest amounts of GNP, in opposition to what was expected.…”