The rheological behavior of a novel, binary organic-inorganic hybrid consisting of an ultra-low Tg tin fluorophosphate glass (Pglass) and polycarbonate (PC) was investigated using oscillatory rheometry. It was found that the complex viscosity of the hybrid showed Pglass content dependence. Under low Pglass content (10-30%), the complex viscosity of the hybrid was lower than that of pure PC. While the complex viscosity was dramatically increased and higher than that of pure PC with the content of Pglass above 30%. This phenomenon was particularly remarkable at low frequencies. Besides, with the addition of Pglass the hybrid material exhibited shear-thinning behavior and the shear-thinning characteristics became more obvious with the enhancement of the Pglass content, indicating the presence of nonlinear chemical and physical interactions between the hybrid components. Differential scanning calorimetry (DSC) measurements revealed that increasing the content of Pglass caused a decrease of the glass transition temperature (Tg) of the hybrids, suggesting that Pglass was acting as a macromolecular plasticizer for the PC. The microstructure of the Pglass in the hybrid material was characterized by scanning electron microscopy (SEM). The results showed that the Pglass were dispersed as micro- and nano-bead in the continuous phase of PC and the Pglass appeared aggregation partly with the increase of the Pglass content. This contribution was anticipated to be a guideline for the processing of this promising new class of hybrid materials.
Silicon nitride (Si 3 N 4 ) ceramic has been widely applied in various engineering fields. The emergence of additive manufacturing (AM) technologies provides an innovative approach for the fabrication of complex-shaped Si 3 N 4 ceramic components. This article systematically reviews the advances of the AM of Si 3 N 4 ceramic in recent years and forecasts the potential perspectives in this field. This review aims to motivate future research and development for the AM of Si 3 N 4 ceramic.
Gas pressure sintering is applied to prepare arbitrary porous silicon nitride (Si3N4) ceramics using yttria (Y2O3) as the sintering additive and naphthalene powder as the pore‐forming agent. The results obtained show that the porosity of the sintered porous Si3N4 ceramics is 40%–54% when the Y2O3 content is from 3 to 15 wt% and the sintering temperature is from 1700° to 1850°C. The bending strength is in the range of 60–226 MPa. The porosity of the porous Si3N4 ceramics with Y2O3 content of 9 wt%, sintered at 1800°C, is increased to 51%–66% when the naphthalene powder content is 5–30 wt%. Finally, large and arbitrary porous Si3N4 ceramics with a porosity of ∼60% can be successfully fabricated by this method.
The dynamic mechanical properties, crystallization behavior and morphology of nanoscale Tg tin fluorophosphate glass (TFP glass)/polyamide 66 (PA66) hybrid materials were investigated by XRD, DSC and SEM. The experimental results showed that the Tg of TFP/PA66 hybrid decreased and the third relaxation in the highly filled hybrid appeared due to the interaction between the TFP glass and amide groups of PA66. The storage modulus of the hybrid materials increased with increase in the content of TFP at low temperatures but had little effect at high temperatures. This result was attributed to the stiffness depression of the TFP glass when the temperature rose above its Tg and the similar elasticity of the two phases because of the interaction between the components. The degree of crystallinity and a, y crystal content of PA66 both decreased due to the interaction between the two phases. In addition, the phase defect, the size distribution and the compatibility of TFP in the PA66 matrix were discussed by SEM, the results showed that the TFP appeared aggregation partly, but had the favorable compatibility in the PA66 matrix.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.