刚性短切碳纤维预制体和酚醛浸渍碳烧蚀体的制备及性能杨

以短切碳纤维、热固性酚醛树脂为原料,经真空成型得到短切碳纤维预制体(Fiberform),再以Fi鄄

berform 为骨架、酚醛树脂溶液为浸渍液,经反应干燥得到酚醛浸渍碳烧蚀体( PICA)。结果表明:Fiberform 具

有明显的各向异性,当Fiberform 的密度由0. 13 g/ cm3增大到0. 18 g/ m3 时,其纵向压缩强度由0. 10 MPa 增大

到0. 39 MPa,横向压缩强度由0. 33 MPa 增大到0. 79 MPa。PICA 具有酚醛气凝胶/ 碳纤维复合型结构,其密度

可以通过控制酚醛树脂溶液浓度来调节。当PICA 的密度由0. 27 g/ cm3增大到0. 43 g/ cm3,其纵向压缩强度由

0. 45 MPa 增大到2. 42 MPa,横向压缩强度由1. 36 MPa 增大到3. 12 MPa。PICA 的隔热性能与Fiberform 相近,

其纵向和横向热导率分别为0. 08 和0. 11 W/ (m·K)。

Preparation and Properties of Rigid Carbon Fiber Preform andResulting Phenolic Impregnated Carbon Ablator

The rigid carbon fiber preform (Fiberform) was prepared by vacuum molding using chopped carbon

fibers as the raw material and thermal setting phenolic resin powder as the cross linking agent. The resulting Fiberform

was further impregnated with phenolic resin solution through reaction and drying process, to obtain phenolic impregna 

ted carbon ablator (PICA). Fiberform consists of interconnected chopped carbon fiber oriented preferentially in the

horizontal direction, making it a transverse isotropic material with different material properties. The longitudinal com 

pressive strength and transverse compressive strength were varied from 0. 10 to 0. 39 MPa and 0. 33 to 0. 79 MPa, re

spectively, depending on the density of Fiberform. PICA had an aerogel like composite structure consisting of phenolic

nanoparticles and carbon fiber network. The density of PICA could be controlled from 0. 27 to 0. 43 g/ cm3 by chan 

ging the concentration of phenolic resin solution. The longitudinal and transverse compressive strengths of PICA were

therefore adjusted from 0. 45 to 2. 42 MPa and from 1. 36 to 2. 27 MPa, respectively. The PICA had the similar ther 

mal insulation with the Fiberform, 0. 08 W/ ( m·K) in through the thickness and 0. 11 W/ ( m·K) in plane direc 

tions.