It has been already pointed out that one of the best ways to increase toughness of the inherently brittle polylactide (PLA) without sacrificing strength and modulus is the use of thermoplastic elastomer toughening approach; but what happens under outdoor conditions was not explored. Therefore, the objective of this study was to explore the degree of losses especially in fracture toughness of PLA when blended with thermoplastic polyurethane (TPU) elastomer or thermoplastic polyester elastomer (TPE) after weathering. For this purpose, neat PLA, its 10 phr TPU and TPE blends were exposed to accelerated weathering conditions of both ultraviolet‐irradiation cycles and moisture cycles as described in the standard of ISO 4892‐3 for various periods. In general, due to the significant molecular weight reduction via chain scission reactions, drastic losses in the strength and toughness of the specimens were observed. On the other hand, in terms of %retention in the properties after weathering periods, it could be suggested that, rather than use of neat PLA, the use of its TPU or TPE blends would be still advantageous for both “indoor use” and also for “outdoor use.” © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47177.

Because of the biocompatible and nontoxic character of both PLA (polylactide) and POSS (Polyhedral Oligomeric Silsesquioxane) nanoparticles, recently being a significant alternative for biomedical parts; the main purpose of this study was to investigate performance of the 3D‐printed PLA/POSS nanocomposites with respect to the compression molded PLA/POSS specimens. Due to the higher uniformity and higher homogeneity in the distribution of POSS nanoparticles in each PLA matrix layer, mechanical tests (tensile, flexural, and toughness) revealed that the improvements in the strength, elastic modulus and fracture toughness values of the 3D‐printed specimens were much higher compared to their compression molded counterparts, the benefits starting from 13% increasing up to 78%. It was also observed that there was almost no deterioration in the physical structure and mechanical properties of the 3D‐printed specimens, even after keeping them 120 days at 37°C in a physiological solution prepared by using the standard PBS (phosphate buffered saline) tablet.

It is known that electrospinning is the most practical technique to obtain unique nanofibrous structures, such as neat PLA (polylactide) and PLA filled with POSS (Polyhedral Oligomeric Silsesquioxane) particles. On the other hand, due to the so many different process parameters to consider, production of these fibers are extremely difficult and time consuming. That is, use of a certain statistical optimization technique in the design of experiments would be necessary. Therefore, the main purpose of this study was to determine the optimum electrospinning parameters by applying the Taguchi technique first to neat PLA and then to reveal the applicability of these parameters for the electrospinning of PLA/POSS nanofibers. It was observed that instead of conducting 81 experiments to determine the most significant four optimum process parameters for PLA, use of Taguchi L 9 orthogonal array experiment matrix, that is, conducting only nine experiments, reduced time, labor and material consumption considerably. For the smallest electrospun PLA fiber diameter, the optimum parameters determined were; "PLA solution concentration" of 8% w/v, "solution feeding rate" of 1.8 mL/h, "needle-to-collector distance" of 18 cm, and "applied voltage" of 15 kV. Moreover, it was generally concluded that these same parameters could be also used for the electrospinning of PLA/POSS nanofibers after addition of only 3 wt% KCl salt into the polymer solution.