CaCO_3作造孔剂制备SiOC块体多孔陶瓷

Preparation of SiOC Bulk Porous Ceramics with CaCO_3 as Pore Forming Agent

实验以含氢聚甲基硅氧烷(PHMS)为基础原料和CaCO_3为造孔剂,以四甲基四乙烯基环四硅氧烷(D_4^(Vi))为交联剂、聚二甲基硅氧烷(PDMS)为裂纹抑制剂和Pt络合物为催化剂,通过热交联和在氮气气氛中热解工艺制备SiOC多孔陶瓷。采用XRD,SEM和BET等检测方法,研究了热解温度,造孔剂添加量等因素对SiOC陶瓷物相组成、微观形貌、比表面积和气孔率等影响规律。结果表明,在热解温度为600~1000℃范围,制备的SiOC多孔陶瓷为无定形(非晶)态,当热解温度为800℃时,未加造孔剂的SiOC陶瓷比表面积为86.45m^2/g、气孔率为9.56%、孔径100~300 nm;而添加15%造孔剂的Si OC陶瓷比表面积为121.92m^2/g、气孔率约13.15%、孔径为100~800nm。

SiOC bulk porous ceramics were prepared by pyrolysis of the thermo-crosslinking in nitrogen atmosphere using hydrogen-containing polysiloxane （PHMS） as the base material, tetramethyl-tetravinylcycletetrasiloxane （D4^Vi） as cross-linking agent, polydimethylsiloxane （PDMS） as crack inhibitor and Pt complex as catalyst, and CaCO3 as poreforming agent. Effects of pyrolysis temperature and adding content of pore-forming agent on phase composition, microstructure, specific surface area and porosity of SiOC ceramic were investigated by XRD, SEM and BET, etc. The results show that SlOG porous ceramics are amorphous at pyrolysis temperature of 600 - 1000 ℃ . When pyrolysis temperature is 800℃ , as-prepared SiOC porous ceramic without pore-forming agent has specific surface area of 86.45 m^2/g , porosity of 9.56%, and pore size distribution of 100- 300 nm. As-prepared SiOC porous ceramic with 15% pore-forming agent owns specific surface area of 121.92 m^2/g, porosity of 13.15%, and pore size distribution of 100 - 800 nm.