泡沫炭的成核机理及其复合增强机制

Preparation of reinforced carbon foams with different fillers

以中间相炭微球（MCMB）、聚丙烯腈基炭纤维（PAN-CF）和纳米氧化锆（Zr O2）为增强体,采用自发泡法制备出泡沫炭复合材料,并研究不同增强材料对中间相沥青基泡沫炭的发泡行为和压缩强度的影响。结果表明,中间相沥青在发泡过程中遵循热点成核机制;较PAN-CF、MCMB而言,Zr O2纳米颗粒（～100 nm）对泡沫炭具有更佳的增强效果。当在中间相沥青原料中添加30%的纳米Zr O2后,泡沫炭的压缩强度可由7.57 MPa提高到31.4 MPa。

Carbon foam composites were prepared by a self- foaming method from mesophase pitch using mesocarbon microbeads（ MCMBs）,PAN based carbon fibers（ PAN-CFs） and Zr O2 nanoparticles were used as the fillers for reinforcement. The effects of the fillers on the foaming behavior and the compressive strength were investigated. Results showthat Zr O2 nanoparticles produce a larger increase in the compressive strength of the carbon foam than do MCMBs and PAN-CFs. The compressive strength of the carbon foam increases from 7. 57 to 31. 4 MPa when 30% of the Zr O2 nanoparticles is added to the mesophase pitch. The foam formation obeys the hot-point nucleation mechanism,in which gaseous products released from light hydrocarbons are heated to generate nuclei by localized condensation reaction heat.