3D printing via fused deposition modeling (FDM) has developed to the probably most common rapid prototyping technology due to its easy of use and broad range of available materials. Nowadays, FDM printed parts are on the way to be used in various applications ranging from all-day use to more technical purposes. As a matter of fact, the mechanical strength is one of the main parameters to be optimized by the choice of the material and the 3D-printing settings, such as layer height, nozzle temperature and printing speed. Here, we report on the improvement of the mechanical properties of printed parts by use of an inert gas atmosphere during the print. A typical FDM printer has been inserted into the nitrogen atmosphere of a glove box and used without modifications to print parts made of acrylonitrile butadiene styrene and polyamide as printing materials with a high mechanical load tolerance. Probably partly due to the prevention of oxidation processes, a significant increase in elongation at break and tensile strength was observed. This may be explained by a reduced degradation of the polymer surface at the comparatively high printing temperature. 3D printing under the exclusion of oxygen may be realized comparatively easy by flooding the printing chamber with nitrogen in future applications for the production of FDM-printed parts with improved mechanical properties.

One aim of this work was the chemical modification of surfaces of Scots pine (Pinus sylvestris L.) sapwood veneer chips by covalently bonded substances for improved hydrophobicity. The durable attachment of organosilyl moieties to the surface was in focus. Several benzotriazolyl-activated p-silylated benzoic acid derivatives were applied to the esterification of OH groups at different temperatures and reaction times. The reactions resulted in weight percent gains from 8% to 43% and corresponding quantities of covalently bonded organomaterials of 0.3-2.1 mmol g -1 wood. The hydrophobicity was significantly increased as indicated by contact angles from 121° to 142°. All modified wood samples were analyzed by attenuated total reflection-infrared, contact angle measurements, and X-ray photoelectron spectroscopy.Keywords: attenuated total reflection-IR (ATR-IR), contact angle (CA), covalent fixation, esterification, hydrophobization of wood surface, quantity of covalently bonded organomaterials (QCO), silicon, X-ray photoelectron spectroscopy (XPS)

For a durable improvement of the hydrophobization properties of wood Scots pine (Pinus sylvestris L.) sapwood veneer chips were covalently modified with surfactant-like p-alkylated benzoates and a corresponding 4-cyanophenyl derivative. These esterification reactions of wood hydroxyl groups at varied temperatures and different reaction times afforded weight percent gains (WPG) ranging from 8 to 44% and quantities of covalently bonded organomaterials (QCO) of 0.3–2.6 mmol per gram, respectively. The successful covalent attachment of the functional precursors was proven by attenuated total reflection-infrared spectroscopy (ATR-IR), while the improvement of hydrophobicity was demonstrated by resulting contact angles (CAs) in a range from 113 to 150°.

A set of push–pull substituted arylnaphthylalkynes has been synthesized under inert gas conditions in 3D-printed cuvettes out of NMR-transparent polyamide and their optical properties were investigated.

3D‐Printing with the well‐established ‘Fused Deposition Modeling’ technology was used to print totally gas‐tight reaction vessels, combined with printed cuvettes, inside the inert‐gas atmosphere of a glovebox. During pauses of the print, the reaction flasks out of acrylonitrile butadiene styrene were filled with various reactants. After the basic test reactions to proof the oxygen tightness and investigations of the influence of printing within an inert‐gas atmosphere, scope and limitations of the method are presented by syntheses of new compounds with highly reactive reagents, such as trimethylaluminium, and reaction monitoring via UV/VIS, IR, and NMR spectroscopy. The applicable temperature range, the choice of solvents, the reaction times, and the analytical methods have been investigated in detail. A set of reaction flasks is presented, which allow routine inert‐gas syntheses and combined spectroscopy without modifications of the glovebox, the 3D‐printer, or the spectrometers. Overall, this demonstrates the potential of 3D‐printed reaction cuvettes to become a complementary standard method in inert‐gas chemistry.