Synthesis of cross‐linked polymer microspheres and pyrolysis conversion to polymer‐derived ceramics

Abstract

The cross‐linked polysilazane spherical particles were synthesized via a solvothermal process from a liquid polysilazane precursor. We found that the average size of obtained cross‐linked polymer spheres is in the range of hundreds nanometer to about 10 μm by adjusting the amount of divinylbenzene cross‐linker. Spherical ceramic particles were synthesized via the polymer‐derived ceramics (PDCs) route. The XRD and SEM analysis on ceramic particles pyrolyzed below 1400°C showed that they were amorphous and maintained a smooth spherical morphology. When the polymer spherical particles were pyrolyzed at 1500°C, SiC/Si3N4 ceramics spheres were fabricated.

Microstructure and phase evolution of polymer‐derived SiHfOC ceramic microspheres

“…Ceramic microspheres have attracted considerable attention in recent years due to their excellent thermal and chemical stabilities, high specific surface areas, as well as multifunctionality, which make them much more advantageous as a filler or reinforcer in many potential fields, including high‐temperature structural components, high‐temperature reaction catalyst supports, electromagnetic microwave absorbing devices, and so forth 1–7 . Common methods for preparing microspheres include sol–gel, 8 emulsion, 4,9 microemulsion flame spraying, 10 and precipitation polymerization 5 .…”

Porous SiC and SiC/Cf Ceramic Microspheres Derived from Polyhydromethylsiloxane by Carbothermal Reduction

“…Spherical particles confined in dimensions within the micrometer range exhibit superior properties to their bulk counterparts. They provide good flowability, high packing density and easy access to particle surfaces [ 7 , 8 , 9 , 10 ]. In addition, hierarchical porosity gives the materials a high surface area and facile infiltration of liquids to their pores [ 7 ].…”

“…Polymer-derived SiC ceramics and their composites are obtained from various precursors, such as polycarbosilanes [ 7 , 24 , 25 ], polysilazanes [ 8 , 9 , 10 , 26 ], polysiloxanes and silicone resins [ 27 , 28 , 29 , 30 , 31 , 32 ]. Polysiloxanes are commercially accessible and less expensive than other SiC precursors.…”

Preparation of rosin-based polymer microspheres as a stationary phase in high-performance liquid chromatography to separate polycyclic aromatic hydrocarbons and alkaloids

“…Polymer microspheres are polymeric materials or polymer composites with sizes ranging from nanometer to micrometer scale and spherical geometrical shapes (1)(2)(3). Polymer microspheres have wide applications in stationary phases, biological medicine and many other fields (4-7).…”