High performance stereolithography resin (SLR) nanocomposites with different amount of modified polyhedral oligomeric silsesquioxane (m-POSS) nanoparticles, which were synthesized through NH 2 -POSS and 2-isocyanatoethyl methacrylate, have been prepared. By copolymerization POSS nanoparticles can be grafted onto the polymer chains of the SLR matrix. The modified structure of POSS nanoparticles was characterized by Fourier transform infrared spectroscopy and 1 H NMR. The effects of m-POSS nanoparticles on morphologies, mechanical and thermal properties of SLR nanocomposites were investigated in detail. The results show that the tensile and flexible strength were improved by 36.2% and 40% respectively with the addition of 5% w/w m-POSS nanoparticles compared to pristine SLR. The nanoindentation analysis shows a significant amelioration in hardness and reduced modulus by the introduction of m-POSS nanoparticles. The results from thermal studies reveal that the incorporation of m-POSS nanoparticles can significantly enhance the glass transition temperature ( T g ), degradation temperature, char yield, and heat distortion temperature of nanocomposites. Moreover, the incorporation of m-POSS nanoparticles would not only improve the mechanical and thermal properties, but also maintain the high fabrication accuracy of the SLR for 3D stereolithography printing.
Hybrid organic/inorganic nanocomposites based on aramid nanofibers (ANFs) and different amounts of polyhedral oligomeric silsesquioxane (POSS) nanostructured chemicals were prepared via solution blending and vacuum-assisted flocculation, compared with traditional film fabrication methods, this process is time-saving by adopting ethanol as agglomerator. The mechanical properties of ANFPs membranes could be altered by changing the POSS content, in which the POSS served as a cross-linking agent between nanofibers, and ANFPs composite membrane presented the optimal tensile strength with 6 wt.% POSS NPs embedding in the nanocomposite. In addition to the satisfactory mechanical performance and vitreousness, the unique thermal assets of ANFs and POSS further enabled the membranes with high thermal stability. Based on these results, it could be concluded that the ANFPs membranes developed here might provide the alternative materials for the practical application of strong, transparent and heat-resistant membrane.
Chengxiang Zhang,Tingxi Li,Hui Song,Yongqin Han,Haibo Su,Yanmin Wang,Qing Wang
To improve the mechanical property of epoxy resin (EP) had received intensive attentions in engineering industries at present. For this reason, three kinds of epoxy resin nanocomposites were prepared by incorporating different POSS nanoparticles. This study showed the toughening effect of three kind of nanocomposites and analyzed the different toughening mechanism. The thermomechanical properties and impact strength of the samples were investigated by means of dynamic thermomechanical analysis (DMA) and XJJ-50 type tester. The thermal stability was examined by thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM) was used to characterize the morphology of fracture surfaces for composites. When introduction of Octavinyl-POSS (OV-POSS), DodecaPhenyl-POSS (DP-POSS) and Methacryl-POSS (M-POSS) was 1.0 phr, the values of impact strength reach 22.60 kJ/m2, 24.90 kJ/m2, 29.61 kJ/m2 and the values of storage modulus get to 2.88 GPa, 2.25 GPa, 2.14 GPa respectively. It can be observed that M-POSS has the most obvious effect when introduced into the same amount of POSS. Meanwhile, adding nanoparticles has no obvious impact on the excellent thermal stability of EP.
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