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以聚硅碳硅烷(PSCS)与乙酰丙酮铝(Al(AcAc)3)为原料,在常压高温条件下反应制备出聚铝碳硅烷(PACS),经过熔融纺丝制备了PACS纤维.应用GPC、IR、XPS、29Si-NMR、27Al-NMR、TG、SEM、元素分析和增重等一系列分析,分别对PACS纤维的微观组成、结构以及性能进行了分析.研究结果表明,以原料质量配比为6∶100(Al(AcAc)3∶PSCS)合成的PACS化学式为SiC2.0H7.5O0.13Al0.018,数均分子量为1700左右,最适宜制备PACS纤维;PACS纤维中主要存在SiC4、SiC3H等结构,同时存在Si—O—Al键;在氮气气氛中,PACS纤维的陶瓷产率达到52%左右;预氧化处理,PACS纤维中Si—H键与空气中的氧反应形成Si—O—Si交联结构,较聚碳硅烷(PCS)纤维易于氧化,经过预氧化的PACS纤维陶瓷产率达到80%左右,是制备耐超高温SiC(Al)陶瓷纤维的合适纤维;用预氧化PACS纤维制备的SiC(OAl)纤维和SiC(Al)纤维抗拉强度高,耐高温性能好.
Polyacetal carbosilane (PACS) was prepared by the reaction of PSCS and Al (AcAc) 3 under normal pressure and high temperature, and PACS fibers were prepared by melt spinning. The microstructure, structure and properties of PACS fibers were analyzed by IR, XPS, 29Si-NMR, 27Al-NMR, TG, SEM, elemental analysis and weight gain, respectively. PACS chemical formula is SiC2.0H7.5O0.13Al0.018, the number average molecular weight of about 1700, the most suitable preparation PACS fiber; PACS fiber mainly exist SiC4, SiC3H Si-H bond in the PACS fiber reacts with the oxygen in the air to form Si-O-Al bond; under the nitrogen atmosphere, the ceramic yield of the PACS fiber reaches about 52%; preoxidation treatment, Si crosslinked structure is easier to oxidize than polycarbosilane (PCS) fiber. The yield of pre-oxidized PACS fiber ceramic reaches about 80%, which is a suitable fiber for preparing ultra-high temperature SiC (Al) ceramic fiber. Pre-oxidized PACS fiber The prepared SiC (OAl) fiber and SiC (Al) fiber have high tensile strength and high temperature resistance.