Preceramic polymer

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The term preceramic polymer refers to one of various polymeric compounds, which through pyrolysis under appropriate conditions (generally in the absence of oxygen) are converted to ceramic compounds, having high thermal and chemical stability. Ceramics resulting from the pyrolysis of preceramic polymers are known as polymer derived ceramics, or PDCs. Polymer derived ceramics are most often silicon based and include silicon carbide, silicon oxycarbide, silicon nitride and silicon oxynitride. Such PDCs are most commonly amorphous, lacking long-range crystalline order. [1]

The field of preceramic polymers and polymer derived ceramics in general emerged from the requirements in aerospace industries for heat shield materials such as fiber reinforced ceramic / ceramic composite materials. [2] The use of preceramic polymers allows for diverse processing techniques relative to conventional ceramic processing. For example, the spinning of fibres, casting of thin films and the molding of complex shapes. Commonly used preceramic polymers include polycarbosilanes and polysiloxanes, which transform through pyrolysis to SiC and SiOC type ceramics respectively. [3]

A low-cost method of creating complex 3D shapes of ceramics components is to use additive manufacturing (AM) in a use a two-step process of first printing the artifact in polymer and then converting it to ceramic using pyrolysis to form polymer derived ceramics (PDCs). [4] This process works with fused filament fabrication (FFF)-based 3-D printing to make fully dense cellular structures, [5] which can be used for scaffolds for bone regeneration that need to be mechanically stable and have a 3D architecture with interconnected pores. [6] Various other 3D printing techniques (e.g., stereolithography, digital light processing, and two-photon polymerization) that are compatible with this strategy have so far been widely investigated. [7] For example, through photopolymerization methods, preceramic polymers can be used in stereolithography approaches, enabling the additive manufacturing of complex shaped ceramic objects. In such methods, by means of irradiation-driven cross-linking, liquid preceramic polymers transform into rigid thermoset polymers that preserve their shape through the following polymer-to-ceramic transformation that takes place in pyrolysis. In this transformation, polymers transform into glassy ceramic products. [1]

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<span class="mw-page-title-main">Silicone</span> Class of polymers or oligomers of siloxanes

A silicone or polysiloxane is a polymer made up of siloxane (−R2Si−O−SiR2−, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking utensils, thermal insulation, and electrical insulation. Some common forms include silicone oil, silicone grease, silicone rubber, silicone resin, and silicone caulk.

<span class="mw-page-title-main">Silicon carbide</span> Extremely hard semiconductor containing silicon and carbon

Silicon carbide (SiC), also known as carborundum, is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite.

<span class="mw-page-title-main">Stereolithography</span> 3D printing technique

Stereolithography is a form of 3D printing technology used for creating models, prototypes, patterns, and production parts in a layer by layer fashion using photochemical processes by which light causes chemical monomers and oligomers to cross-link together to form polymers. Those polymers then make up the body of a three-dimensional solid. Research in the area had been conducted during the 1970s, but the term was coined by Chuck Hull in 1984 when he applied for a patent on the process, which was granted in 1986. Stereolithography can be used to create prototypes for products in development, medical models, and computer hardware, as well as in many other applications. While stereolithography is fast and can produce almost any design, it can be expensive.

<span class="mw-page-title-main">3D printing</span> Additive process used to make a three-dimensional object

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<span class="mw-page-title-main">Photopolymer</span>

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<span class="mw-page-title-main">Sirris</span>

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Silicon oxynitride is a ceramic material with the chemical formula SiOxNy. While in amorphous forms its composition can continuously vary between SiO2 (silica) and Si3N4 (silicon nitride), the only known intermediate crystalline phase is Si2N2O. It is found in nature as the rare mineral sinoite in some meteorites and can be synthesized in the laboratory.

<span class="mw-page-title-main">Polysilane</span>

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<span class="mw-page-title-main">Fused filament fabrication</span> 3D printing process

Fused filament fabrication (FFF), also known as fused deposition modeling, or filament freeform fabrication, is a 3D printing process that uses a continuous filament of a thermoplastic material. Filament is fed from a large spool through a moving, heated printer extruder head, and is deposited on the growing work. The print head is moved under computer control to define the printed shape. Usually the head moves in two dimensions to deposit one horizontal plane, or layer, at a time; the work or the print head is then moved vertically by a small amount to begin a new layer. The speed of the extruder head may also be controlled to stop and start deposition and form an interrupted plane without stringing or dribbling between sections. "Fused filament fabrication" was coined by the members of the RepRap project to give an acronym (FFF) that would be legally unconstrained in its use.

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Oxycarbide glass, also referred to as silicon oxycarbide, is a type of glass that contains oxygen and carbon in addition to silicon dioxide. It is created by substituting some oxygen atoms with carbon atoms. This glass may contain particles of amorphous carbon, and silicon carbide. SiOC materials of varying stoichiometery are attractive owing to their generally high density, hardness and high service temperatures. Through diverse forming techniques high performance parts in complex shapes can be achieved. Unlike pure SiC, the versatile stoichiometry of SiOC offers further avenues to tune physical properties through appropriate selection of processing parameters.

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High-area rapid printing (HARP) is a stereolithography (SLA) method that permits the continuous, high-throughput printing of large objects at rapid speeds. This method was introduced in 2019 by the Mirkin Research Group at Northwestern University in order to address drawbacks associated with traditional SLA manufacturing processes. Since the polymerization reactions involved in SLA are highly exothermic processes, the production of objects at high-throughputs is associated with high temperatures that can result in structural defects. HARP addresses this problem by utilizing a solid-liquid slip boundary that cools the resin by withdrawing heat from the system. This allows for large structures to be fabricated quickly without the temperature-associated defects inherent to other SLA processes.

References

  1. 1 2 Kizhakke Veettil et al. A versatile stereolithographic approach assisted by thiol-ene click chemistry, Additive Manufacturing 2019, volume 27 pages 80-90
  2. Preceramic Polymers: Past Present and Future, Office of Naval Research
  3. "Ceramic Forming Polymers". Starfire Systems. Retrieved 2021-08-18.
  4. Kulkarni, Apoorv; Sorarù, Gian Domenico; Pearce, Joshua M. (2020-03-01). "Polymer-derived SiOC replica of material extrusion-based 3-D printed plastics". Additive Manufacturing. 32: 100988. arXiv: 1909.02442 . doi:10.1016/j.addma.2019.100988. ISSN   2214-8604. S2CID   202537657.
  5. Kulkarni, Apoorv; Pearce, Joshua; Yang, Yuejiao; Motta, Antonella; Sorarù, Gian Domenico (2021). "SiOC(N) Cellular Structures with Dense Struts by Integrating Fused Filament Fabrication 3D Printing with Polymer‐Derived Ceramics". Advanced Engineering Materials. 23 (12): 2100535. doi: 10.1002/adem.202100535 . ISSN   1438-1656. S2CID   237749100.
  6. Yang, Yuejiao; Kulkarni, Apoorv; Soraru, Gian Domenico; Pearce, Joshua M.; Motta, Antonella (2021). "3D Printed SiOC(N) Ceramic Scaffolds for Bone Tissue Regeneration: Improved Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells". International Journal of Molecular Sciences. 22 (24): 13676. doi: 10.3390/ijms222413676 . ISSN   1422-0067. PMC   8706922 . PMID   34948473.
  7. Rasaki, Sefiu Abolaji; Xiong, Dingyu; Xiong, Shufeng; Su, Fang; Idrees, Muhammad; Chen, Zhangwei (2021-06-01). "Photopolymerization-based additive manufacturing of ceramics: A systematic review". Journal of Advanced Ceramics. 10 (3): 442–471. doi: 10.1007/s40145-021-0468-z . ISSN   2227-8508. S2CID   232371172.