Synthesis of SiOC using solvent-modified polymer precursors
Synthesis of SiOC using solvent-modified polymer precursors
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DOI：
10.1016/j.matchemphys.2019.121844
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发表时间：
2019-11-01
影响因子：
4.6
通讯作者：
Lu, Kathy
中科院分区：
文献类型：
--
作者：
Erb, Donald;Lu, Kathy
碳氧化硅陶瓷是一类重要的材料，可以在加工过程中进行改性以覆盖广泛的微观结构和成分。本研究的重点是聚硅氧烷前体的SiOC转化率交联时，在0，50，100，和200体积%的3-戊酮，正庚烷，或异丁基苯的存在下，相对于体积的聚硅氧烷。溶剂改性的样品显示出体积密度的降低和开孔率的增加。溶剂的加入促进了结晶SiC的形成，特别是对于3-戊酮。溶剂促进SiC形成的能力与溶剂分子尺寸直接相关，较小的溶剂更可能增加聚合物链缠结并在干燥后保持捕获在聚合物内，随后在热解后产生更多的C-C和Si-C键。这项工作显示了溶剂在改性SiOC的微观结构和性能方面的独特功能。
Silicon oxycarbide ceramics are an important class of materials that can be modified to cover a wide range of microstructures and compositions during processing. This study focuses on a polysiloxane precursor to SiOC conversion when crosslinked in the presence of 0, 50, 100, and 200 vol% of 3-pentanone, n-heptane, or isobutylbenzene, relative to the volume of the polysiloxane. The solvent modified samples show a decrease in bulk density and an increase in open porosity. The addition of the solvents facilitates the formation of crystalline SiC, especially for 3-pentanone. The ability of the solvents to encourage SiC formation is directly related to the solvent molecular size, with smaller solvents being more likely to increase polymer chain entanglement and remain trapped within the polymer after drying and subsequently creating more C-C and Si-C bonds after pyrolysis. This work shows the unique function of solvents in modifying the SiOC microstructures and properties.