The use of biobased plastics is of great importance for many applications. Blending thermoplastic polylactide (PLA) with polyhydroxyalkanoate (PHA) enables the formulation of a more mechanically powerful material and this enables tailored biodegradation properties. In this study we demonstrate the 3D printing of a PLA/PHA blend as a potential candidate for biocompatible material applications. The filament for 3D printing consisted of PHA, which contains predominantly 3-hydroxybutyrate units and a small amount of 3

Degradation of poly[(1,4-butylene terephthalate)-co-(1,4-butylene adipate)] (Ecoflex, BTA) monofilaments (rods) in standardized sandy soil was investigated. Changes in the microstructure and chemical composition distribution of the degraded BTA samples were evaluated and changes in the pH and salinity of postdegradation soil, as well as the soil phytotoxicity impact of the degradation products, are reported. A macroscopic and microscopic evaluation of the surface of BTA rod samples after specified periods of incubation in standardized soil indicated erosion of the surface of BTA rods starting from the fourth month of their incubation, with almost total disintegration of the incubated BTA material observed after 22 months. However, the weight loss after this period of time was about 50% and only a minor change in the M(w) of the investigated BTA samples was observed, along with a slight increase in the dispersity (from an initial 2.75 up to 4.00 after 22 months of sample incubation). The multidetector SEC and ESI-MS analysis indicated retention of aromatic chain fragments in the low molar mass fraction of the incubated sample. Phytotoxicity studies revealed no visible damage, such as necrosis and chlorosis, or other inhibitory effects, in the following plants: radish, cres, and monocotyledonous oat, indicating that the degradation products of the investigated BTA copolyester are harmless to the tested plants.

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This paper presents the course of synthesis and the properties of biodegradable terpolymers obtained by ROP of L-lactide with glycolide, catalysed with zirconium(IV) acetylacetonate and conducted in the presence of a macroinitiatortrimethylene carbonate oligomers terminated with hydroxyl groups. The oligomers were also prepared by ROP reaction of TMC catalysed by zinc(II) acetylacetonate monohydrate in the presence of polyols as initiators. Depending on the type of initiator used, the oligomers had a linear or branched structure of the chain with different hydroxyl end-groups. Some of the obtained oligomers formed a network. The effect of the terpolymer chain structure on mechanical and thermomechanical properties as well as shape-memory behaviour was shown. The ability to control the speed of return from a temporary to a permanent shape, the value of stress of return triggered by this phenomenon, and the magnitude of the temperature range in which the phenomenon took place through appropriate selection of conditions for programming the temporary shape or/and terpolymer chain microstructure has been shown. The possibility of adjusting these parameters as presented in this paper is vital in the process of designing a bioresorbable material, which can be used for forming selfexpanding stents or self-clamping surgical staples.

This paper presents ex-ante examination of advanced polymer materials to detect defects and define and minimize the potential failure of novel polymer products before they arise. The effect of build directions on the properties of dumbbell-shaped specimens obtained by three-dimensional printing from polylactide and polylactide/polyhydroxyalkanoate commercial filaments was investigated, as well as the hydrolytic degradation of these specimens at 50 ºC and 70 ºC. Taking into account previous studies, we have found further dependences of the properties of 3D printed species before and during abiotic degradation from the orientation of printing. The initial assumption that only the contact time with the 3D printer platform leads to an increase in the crystalline phase during printing turned out to be insufficient. Further investigations of individual parts of the dumbbell-shaped specimens showed that the size of the specimens' surface in contact with the platform also affected the structural ordering of the material.

The degradation of the advanced polymeric materials: blends of polylactide with poly[(R,S)-3-hydroxybutyrate] was studied in paraffin (an ingredient used in cosmetics) and compared with the degradation of pure poly[(R,S)-3-hydroxybutyrate]. The interaction between the polymeric materials studied and the paraffin was monitored during the degradation experiments, and the effects of this interaction were reported. Gel permeation chromatography, atomic force microscopy, electrospray mass spectrometry, nuclear magnetic resonance, differential scanning calorimetry and thermal gravimetric analysis revealed that degradation of the investigated materials occurs in the presence of paraffin. In the blends, poly[(R,S)-3-hydroxybutyrate] content was found to extend the disintegration time, and for the blends with good miscibility, reduced the degradation rate in the first step of degradation.