Influence of the processing parameters and composition on the thermal stability of PLA/nanoclay bio‐nanocomposites

Abstract

Poly(lactic acid) (PLA) is one the most promising bio-based and biodegradable polymer. However, its low thermal stability limits the range of applications and complicates its transformation via the most industrial common processes. The novelty of this work is studying the thermal stability of PLA and PLA/clay nanocomposites during use, as a function of the composition and using a wide range of extrusion and injection moulding processing parameters. To improve the thermal stability of the PLA, laminar silicates containing different organomodifications have been added (Cloisite 20A and Cloisite 30B). The results show that the processing conditions and composition define the morphology of the bio-nanocomposites, which plays key role in defining final thermal properties of the material. In general, clays improve the thermal stability of the processed material, increasing the degradation temperature and decreasing the degradation rate under a wide range of processing conditions. V C 2014 Wiley Periodicals, Inc. J.Appl. Polym. Sci. 2014, 131, 40747.

Quantitative electron tomography of PLA/clay nanocomposites to understand the effect of the clays in the thermal stability

“…Considering the nanoflake morphology of the particles, it is clear that the obtained d cp values (measured as the minimum Feret diameter) cannot be correct. In fact, those values are much higher than the ones measured using X‐ray . Still, the tomography‐based thickness values can be used to compare both nanocomposites.…”

“…The results obtained from this analysis are shown in Table . As a reference, the results for processed PLA (same conditions as the nanocomposites) are included …”

“…Before processing, the PLA was dried for 4 h at 80 °C and the clay for 12 h at 80 °C. The samples were also pre‐dried for a injection moulding for 4 h at 80 °C, and A type specimens were injection moulded according to ISO 527 in a Sandretto OTTO 150 Tn injection moulding machine …”

“…T onset is defined as the temperature at which 10% of the mass has been lost and Δ T d is the temperature interval between T onset and the temperature at which 90% of the mass has been lost. These parameters are considered to be suitable to describe the degradation related to the nanocomposite …”

Study on Thermal Performance of Composites Prepared Using Poly(L-Lactic Acid) and Melamine

“…For examples, clay is often used to improve the performance of PLLA. Maider et al reported the use of clay could increase the thermal stability of PLLA/nanoclay nanocomposites, and decreased the degradation rate during processing [4]. Cele et al [5] also used clay to investigate the effect of nanoclay on optical properties of PLLA/clay films.…”