浸渍用有机聚锆前驱体的制备与表征

Preparation and Characterization of Zirconium-containing Ceramic Precursor Used for Impregnation

为获得成本低，毒性小的浸渍用ZrC陶瓷前驱体，以苯酚、甲醛、八水氧氯化锆、乙酰丙酮和双氧水为原料，制备了有机聚锆前驱体（PZC）．该前驱体在空气中可稳定存在，易溶于乙醇，可被稀释到任意黏度．采用XPS、XRD、NMR、FTIR、流变仪和TG—DSC对前驱体的组成与结构进行了表征，并对其动态黏度以及裂解过程进行了分析．结果表明，采用乙醇为溶剂，乙酰丙酮为配位剂，可成功的将锆引入聚合物分子链中，并以Zr-O和Zr-O—C的形式存在；反应过程中，乙酰丙酮与八水氧氯化锆所形成的络合物为主反应物，通过配位反应与羟甲基酚生成直线双链型结构的PZC；黏度分析表明，该前驱体在较宽的温度范围（40～100℃）具有较低的黏度（50～800mPa·s），适合做浸渍剂；该前驱体在1400℃下惰性气氛中裂解，残碳率为48％，可以作为优良的浸渍用陶瓷前驱体使用．

A kind of low cost and toxicity ceramic precursor with zirconium （PZC） used for impregnation was successfully synthesized with phenol, paraformaldehyde （PA） , ZrOC12 · 8H2O, acetylacetone （Hacac） and H2O2 as raw materials. The precursor was air stable and can be diluted in ethanol to any expected viscosity. The composition, structure, viscosity and pyrolysis process of the precursor were analyzed by X-ray diffractometer （XRD） , X-ray photoelectron spectroscopy （XPS） , nuclear magnetic resonance （NMR） , Fourier transform infrared spectra （FTIR） , the cone and plate rheometer and thermogravimetric analyser-differential scanning calorimetry （TG-DSC）. The results showed that incorporation of Zr-- on to the polymer backbone was successfully done, using Hacac as complexing agent and ethanol as solvent, and the obtained precursor might be Zr--O and Zr--O--C chain polymer with acetylacetone and hydroxymethyl phenol as ligands. During reaction,the coordination compound [ Zr] prepared by the coordination reaction between ZrOC12 · 8H2O and acetylacetone （Hacac） was the main reactive group. And PZC was prepared by the coordination reaction of [Zr] and the hydroxymethyl phenol which was synthesized by reaction between phenol and formaldehyde. Results indicated that the precursor showed long temperature range of 40 -80 % and low viscosity of 50 - 800 mPa · s,which was suitable for impregnation. The ceramic yield ratio of the precursor was 48% at 1400 ℃ , pyrolysis products were ZrO2 and ZrC,while initial formation temperature of ZrC was higher than 1200 ℃ , and the precursor transformed into ZrC completely at 2000 ℃. Thus,it is a kind of ceramic precursor suitable for infiltration and pyrolysis to obtain ZrC modified carb0n/carbon composites.