Fused deposition modeling (FDM) is a rapidly growing 3D printing technology. However, printing materials are restricted to acrylonitrile butadiene styrene (ABS) or poly (lactic acid) (PLA) in most Fused deposition modeling (FDM) equipment. Here, we report on a new high-performance printing material, polyether-ether-ketone (PEEK), which could surmount these shortcomings. This paper is devoted to studying the influence of layer thickness and raster angle on the mechanical properties of 3D-printed PEEK. Samples with three different layer thicknesses (200, 300 and 400 μm) and raster angles (0°, 30° and 45°) were built using a polyether-ether-ketone (PEEK) 3D printing system and their tensile, compressive and bending strengths were tested. The optimal mechanical properties of polyether-ether-ketone (PEEK) samples were found at a layer thickness of 300 μm and a raster angle of 0°. To evaluate the printing performance of polyether-ether-ketone (PEEK) samples, a comparison was made between the mechanical properties of 3D-printed polyether-ether-ketone (PEEK) and acrylonitrile butadiene styrene (ABS) parts. The results suggest that the average tensile strengths of polyether-ether-ketone (PEEK) parts were 108% higher than those for acrylonitrile butadiene styrene (ABS), and compressive strengths were 114% and bending strengths were 115%. However, the modulus of elasticity for both materials was similar. These results indicate that the mechanical properties of 3D-printed polyether-ether-ketone (PEEK) are superior to 3D-printed ABS.

(X. Liang).Statistics. Data are presented as mean ± SEM, and a 2-tailed t test was used for 2-group comparisons. Differences were considered statistically significant at a value of P < 0.05.Study approval. All the experiments involving mice were carried out in accordance with protocols approved by the Institutional Animal Care and Use Committee of USCD (A3033-01) and by the Animal Committee of Tongji University School of Medicine (TJmed-010-10).

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Selective hydrogenation of cinnamaldehyde (CAL) is an important reaction because the main products, cinnamic alcohol (COL) and hydrocinnamaldehyde (HCAL), are used in various fields, such as production of pharmaceutical intermediates, chemicals, perfumes, and fragrances. In recent years, numerous metal-based catalysts and significant study achievements have been reported. Thus, this Review focuses on selective hydrogenation of CAL to target products in terms of metal-based catalysts and summarizes recent developments in this reaction with different catalysts, including Pt-, Pd-, Ru-, Ni-, Co-, and Cu-based catalysts.In addition, the reaction mechanisms of different catalysts, the effects of catalyst substrates, the different catalyst structures, and the synergistic effects in bimetallic catalysts are discussed. Lastly, the limitations and barriers encountered for noble metal and non-noble metal catalysts in the current study as well as potential research trends are discussed.

The success of the 3D-printing process depends upon the proper selection of process parameters. However, the majority of current related studies focus on the influence of process parameters on the mechanical properties of the parts. The influence of process parameters on the shape-memory effect has been little studied. This study used the orthogonal experimental design method to evaluate the influence of the layer thickness H, raster angle θ, deformation temperature Td and recovery temperature Tr on the shape-recovery ratio Rr and maximum shape-recovery rate Vm of 3D-printed polylactic acid (PLA). The order and contribution of every experimental factor on the target index were determined by range analysis and ANOVA, respectively. The experimental results indicated that the recovery temperature exerted the greatest effect with a variance ratio of 416.10, whereas the layer thickness exerted the smallest effect on the shape-recovery ratio with a variance ratio of 4.902. The recovery temperature exerted the most significant effect on the maximum shape-recovery rate with the highest variance ratio of 1049.50, whereas the raster angle exerted the minimum effect with a variance ratio of 27.163. The results showed that the shape-memory effect of 3D-printed PLA parts depended strongly on recovery temperature, and depended more weakly on the deformation temperature and 3D-printing parameters.