Effect of Intermittent Coating on Property of Carbon/Epoxy Composite

• Main Authors: Hu, Shin Jen, 胡士仁
• Other Authors: Wu, Ching Shiun
• Format: Others
• Language: zh-TW
• Published: 1993
• Online Access: http://ndltd.ncl.edu.tw/handle/31341741950466774268

碩士 === 逢甲大學 === 紡織工程研究所 === 81 === The primary concern of this thesis is the modification of carbon fiber／epoxy composite interfaces with intermittent or continuous polymeric interlayer to improve the impact strength and interlaminar shear strength (ILSS) of composites. Uniform interlayers of acrylonitrile and glycidyl acrylate were applied onto the surface of commerical carbon fibers by an electrochemical polymerization technique. Thickness of the interlayer is controlled by the applied current density and time. Pullout technique has been applied to meassure the interfacial shear strength, τ , between the single carbon fiber and the droplet of epoxy resin. In order to make the pull- out meassurement property, the length of embedded fiber must be less 60 μm or the fiber will rupture before pull-out. τ of the glycidyl acrylate and acrylonitrile coated fibers have a little improvement compared to control.All of the coated systems showed simultaneous improvement in impact and interlaminar shear strength. The interlaminar shear strength increases with increasing intermittent length (i.e. coating coefficient, C ) of the acrylonitrile coating, while decreases with increasing intermittent length of the glycidyl acrylate coating. Both coated materials give similar impact strength that decrease with increasing C. Both ILSS and impact strength results show that intermittent coating can improve the impact strength of composites and maintain the ILSS of composites when the interlayer is ductile (in nature such as GA coating series). The optimum coating coefficient of interlayers are different with different chemical and physical properties. For example, the 75 % AN coated composite was able to increase impact and interlaminar shear strength simultaneously by 20.5 and 50.3 %, while the 25 % GA coated composite could increase impact and interlaminar shear strength by 19.7 and 45.6 %, respectively. The result shows that the 75 % AN and 25 % GA coating may be the optimum condition of this study.