短切/连续碳纤维协同增强本征导热环氧树脂基复合材料研究

Study on synergistic reinforcement of intrinsically conductive epoxy resin matrix composites with short⁃cut/continuous carbon fibers

采用含有联苯介晶基元结构的3,3’,5,5’-四甲基联苯二酚二缩水甘油醚(TMBP)与含有芳香酰胺介晶基元结构的固化剂4,4-二氨基苯酰替苯胺(DABA)制备本征导热TMBP/DABA环氧树脂。结果表明,热导率高达0.33 W/(m·K),比普通双酚A缩水甘油醚(DGEBA)/4,4’-二氨基二苯甲烷(DDM)环氧树脂的热导率高约50%,相应短切碳纤维(含量为75%,质量分数,下同)增强复合材料面外和面内热导率分别高约42.7%和40.2%。采用紫外臭氧氧化方法对短切碳纤维(SCF)和连续碳纤维(M55J)进行表面改性,发现能够明显改善纤维与基体树脂之间的界面结合强度,进而提高复合材料的导热性能。进一步采用SCF和M55J为增强纤维、本征导热TMBP/DABA环氧树脂为基体树脂制备出短切/连续碳纤维协同增强本征导热环氧树脂基复合材料SCF/M55J/TMBP/BADA。SCF的加入能够同时改善M55J/TMBP/DABA单向复合材料板沿X、Y、Z轴方向的热导率,分别最高达到98.07、48.23、9.40 W/(m·K)。为改善复合材料综合导热性能提供了一种新思路。

An intrinsically conductive TMBP/DABA thermosetting epoxy resin was prepared by using 3,3’,5,5’‐tetramethylbifenol diglycyl ether(TMBP)containing diphenyl mesogenic unit as a raw material and 4,4‐diaminobenzanilide(DABA)containing aromatic amide mesogenic unit(DABA)as a curing agent.The resultant epoxy resin achieved a thermal conductivity as high as 0.33 W/(m·K).Compared to the conventional bisphenol‐A glycidyl ether(DGEBA)/4,4'‐diaminodiphenyl methane(DDM)epoxy resin,the as‐prepared epoxy resin obtained an increase in thermal conductivity by about 50%.The out‐of‐plane and in‐plane thermal conductivities of the composites reinforced with 75 wt%shortcut carbon fiber were increased by about 42.7%and 40.2%,respectively.The interface bonding strength between the TMBP/DABA matrix resin and short‐cut carbon fiber(SCF)or continuous carbon fiber M55J was significantly improved by ultraviolet ozone oxidation method at an optimum modification time of 1 h.The thermal conductivity of the composite was also improved.The SCF/M55J/TMBP/BADA composites were prepared by using intrinsically conductive TMBP/DABA epoxy resin as a matrix resin and SCF and M55J as reinforcement fibers.The addition of SCF can simultaneously improve the thermal conductivities of M55J/TMBP/DABA unidirectional composite plates along the X,Y and Z axes,reaching maximum values of 98.07,48.23 and 9.40 W/(m·K),respectively.This work provides a new strategy for improving the comprehensive thermal conductance of composite materials.