Preceramic Polymers: Past, Present and Future

Seyferth, Dietmar

doi:10.21236/ada258327

Cited by 3 publications

(5 citation statements)

References 13 publications

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“…2(a). The absorbance peaks were respectively centred at 3380/1176 cm −1 (N-H), 2959/2900 cm −1 (C-H 3 ), 2128 cm −1 (Si-H), 1255 cm −1 (Si-CH 3 ) and 930 cm −1 (Si-N-Si) [9]. Under the pyrolysis condition for preparing 3D-SFSN composites, PHMS-derived product (i.e., the matrix for the composites) showed a near ceramic state with disappeared or extremely weak absorption peaks of N-H, C-H 3 , Si-H and Si-CH 3 , but strong peaks in the vicinity of 930cm −1 assigned to asymmetric Si-N-Si vibration in the infrared spectrum (see Fig.…”

Section: Resultsmentioning

confidence: 99%

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PIP Preparation of Silica Fibre Fabric Reinforced Silicon Nitride-Based Composites using Polyhydridomethylsilazane

Zhang

et al. 2005

Advanced Composites Letters

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A new type of composites, three-dimensional silica fibre fabric reinforced silicon nitride-based composites, were prepared by PIP method through repeated infiltration of polyhydridomethylsilazane and pyrolysis at 773-873K in ammonia atmosphere. The density of the composites reached 1.66g/cm 3 after four PIP cycles, and the flexural strength was 56.3 MPa. The composites showed a near-brittle fracture mode without long fibre pull-out in the fracture surface. It was the relatively strong fibre/matrix interface bonding that led to the moderate mechanical property.

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Section: Resultsmentioning

confidence: 99%

“…1) with the fibre volume fraction about 44% by Nanjing Fibreglass Research and Design Institute, China. The starting preceramic precursor, a low viscosity (30 MPa s, 298K) transparent liquid that could be cured into polyhydridomethylsilazane (PUMS), was synthesized by the ammonolysis of CH 3 SiHCl 2 [8–9].…”

Section: Methodsmentioning

confidence: 99%

PIP Preparation of Silica Fibre Fabric Reinforced Silicon Nitride-Based Composites using Polyhydridomethylsilazane

Zhang

et al. 2005

Advanced Composites Letters

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“…The following chemicals were used without further purification. Polysilazane preceramic polymers , of molecular weight ≈1300 (NCP-200) and ≈6500 (NCP-100) were obtained as powders from Nichimen Corp., Los Angeles, CA, manufactured by Chisso Corp., Japan. These precursors were synthesized by reaction of NH 3 with mixtures of methyldichlorosilane and dimethyldichlorosilane, followed by condensation reactions, involving KH, to increase the molecular weight and form oligomers based on a repeat unit represented in the approximate formula, T−[Si 8 N 8 R 12 H 5 ] n −T, where R = CH 3 , and T = a terminating group such as H or OH.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…In the three decades since the proposal of the concept of converting ceramic precursors in the form of preceramic polymers to covalently bonded ceramics, an ever-growing body of research has been conducted to explore the development of processes for the synthesis of preceramic polymers and their controlled decomposition into nonoxide ceramics − such as Si 3 N 4 , SiC, AlN, and BN. Target applications of extensive interest include ceramic fibers, − ceramic fiber composites, monolithic ceramics, − powders, and coatings. − …”

Section: Introductionmentioning

confidence: 99%

Chemical Synthesis of Microporous Nonoxide Ceramics from Polysilazanes

et al. 1997

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In a search for a generic synthesis methodology to produce microporous, nonoxide ceramics, pyrolysis of silicon-based preceramic polymers has been studied in inert (He or Ar) and reactive (NH 3 ) atmospheres over the temperature range 25-1300 °C. Pyrolysis of polysilazanes in an inert atmosphere in the absence of additives produced only low-density, nonmicroporous solids. However, four successful approaches to induce microporosity were developed, involving controlled reaction of selected low molecular weight polysilazane preceramic polymers. The first method employs the formation of colloidal polysilazane mixtures with micron-size particles of ceramics such as Si 3 N 4 , SiC, and AlN, followed by their pyrolysis in He or NH 3 to form a ceramic-ceramic composite. The second method involves the synthesis of a nanoscale, polysilazane-stabilized metal colloid of a noble or transition metal and its conversion to a metal-or cermet-ceramic composite by pyrolysis in He or NH 3 . In the third method, a polysilazane is pyrolyzed in NH 3 at low heating rates, to form an amorphous, covalent ceramic. The fourth method involves the pyrolysis of polysilazane/metal-organic mixtures in He or NH 3 . The microporous solids formed by these techniques have surface areas up to >500 m 2 /g and micropore volumes up to >0.20 cm 3 /g as determined by nitrogen adsorption measurements. Hexane adsorption measurements indicate that the micropore space is accessible to hydrocarbons.

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“…Since the density values for the polymer (1-1.2 g/cm 3 ) and ceramic phases (2-3.2 g/cm 3 ) vary significantly, the resulting ceramic residue after pyrolysis may experience shrinkage of up to 70% in volume that leads to the development of considerable porosity or cracks. Therefore, achieving a ceramic yield above 60% is expected after pyrolysis [28]. Higher ceramic yield is more desirable for a preceramic polymer, resulting in less shrinkage and, subsequently, being less prone to defects, such as cracks and bubbles [29].…”

Section: Properties Of Si-based Polymersmentioning

confidence: 99%

Preceramic Polymers for Additive Manufacturing of Silicate Ceramics

Sarraf,

Churakov,

Clemens

2023

Polymers

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The utilization of preceramic polymers (PCPs) to produce both oxide and non-oxide ceramics has caught significant interest, owing to their exceptional characteristics. Diverse types of polymer-derived ceramics (PDCs) synthesized by using various PCPs have demonstrated remarkable characteristics such as exceptional thermal stability, resistance to corrosion and oxidation at elevated temperatures, biocompatibility, and notable dielectric properties, among others. The application of additive manufacturing techniques to produce PDCs opens up new opportunities for manufacturing complex and unconventional ceramic structures with complex designs that might be challenging or impossible to achieve using traditional manufacturing methods. This is particularly advantageous in industries like aerospace, automotive, and electronics. In this review, various categories of preceramic polymers employed in the synthesis of polymer-derived ceramics are discussed, with a particular focus on the utilization of polysiloxane and polysilsesquioxanes to generate silicate ceramics. Further, diverse additive manufacturing techniques adopted for the fabrication of polymer-derived silicate ceramics are described.

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Preceramic Polymers: Past, Present and Future

Cited by 3 publications

References 13 publications

PIP Preparation of Silica Fibre Fabric Reinforced Silicon Nitride-Based Composites using Polyhydridomethylsilazane

PIP Preparation of Silica Fibre Fabric Reinforced Silicon Nitride-Based Composites using Polyhydridomethylsilazane

Chemical Synthesis of Microporous Nonoxide Ceramics from Polysilazanes

Preceramic Polymers for Additive Manufacturing of Silicate Ceramics

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