碳纤维表面上浆处理

• Chemical structure
• Surface enegy and wettability
• Thermal stability and IFSS
Results
A number of longitudinal streaks dispers on the C-1-sized carbon fibers surface, The longitudinal streaks in the C-2 and C-3-sized carbon fibers almost disappeared .A few granular substances appeared on C-3-sized carbon fibers .there was no bundle between C-2-sized carbon fibers, and the fiber bundle had uniform dispersibility. However, some C-3-sized carbon fibers adhered together which did not satisfactory processability and other workability for further application. As a result, we chose C-2 with the concentration of 0.5 wt % as the sizing agent for the following investigation. The results of this study revealed that sizing agent with thermoplastic PPEK resin improved carbon fibers surface and interfacial properties of carbon fiber composites. XPS results confirmed that the main component of sizing agent on T700M CF was PPEK resin. T700M CF performed better thermal stability than that of T700 CF. Because of more functional groups on surface, T700M CF showed higher polar component and surface energy than T700 and T700T carbon fibers. Surface energy of T700M CF was 49.96 mJ m-2, improving 59.26% compared to T700T CF. The wetting performance of T700M was best with the contact angle of 57.01°, and the values were 73.11° and 97.05° for T700 and T700T carbon fibers, respectively. IFSS of T700M CF/PPEK composite was 51.49 MPa and improved 30.32% compared to 700T CF/PPEK composite. Carbon fiber sizing with PPEK can distinctly improve their thermal stability, surface energy, wetting performance, and IFSS.
碳纤维表面上浆处理
PropePoly(phthalazinone ether ketone) Resin
• 碳纤维是脆性材料，在生产及加工过程中，经机械摩擦容易起毛，或 出现单丝断裂等现象，使纤维强度降低。而且，由于毛丝的存在，树 脂基体不能充分浸湿碳纤维，在复合材料制备中容易产生空隙，从而 影响复合材料的力学性能。另外，毛丝的存在还会对工作环境产生影 响，可能造成电气设备、仪表等短路事故，严重影响到生产和安全。 上浆处理是解决上述问题的主要方法。 • 上浆就是经表面处理的碳纤维表面涂一层保护层大约几十nm厚，通常 为有机物。主要作用就是减少起毛断丝现象，使碳纤维集束，改善加 工性能并起保护作用。 • 上浆剂主要与基体树脂相匹配。对于一定的基体树脂，必须选用合适 的上浆剂。目前主要用环氧树脂 ，酚醛树脂等热固性树脂，而对热 塑性上浆剂的研究较少。 • 本次主要介绍热塑性的PPEK(聚苯醚酮树脂）作为碳纤维的上浆剂， 用TGA分析碳纤维热性能，扫描电子显微镜和原子力显微镜观察表面 形态，XPS研究上浆与未上浆碳纤维的表面化学成分，接触角测试分 析碳纤维与PPEK的浸润性和碳纤维的表面能，微脱粘法分析纤维与 PPEK复合材料的层间剪切强度。
Preparation
To campare the PPEK-sizing agent and the sizing agent on T700(with the composition unknown)and get better sizing effect ,the sizing agent coated on T700 CFsurface was removed first.T700 CF was refluxed by boiling acetone for 48h in a Soxhlet apparatus,then washed repeatedly with deionized water,and dried under vacuum at 110℃ for 3h(labeling as T700T,with the diameter of 7.05 um). • Three concentrations of sizing agent, 0.1, 0.5, and 1 wt %, were used and labeled as C-1, C-2, and C-3, respectively. The PPEKresin was dissolved in NMP by constant stirring until the resin was homogeneously dispersed under 80℃. Then the surfactant EL was added to the solution with the concentration of 0.5 wt% of the solution to improve the wettability between unsized carbon fiber and the sizing agent solution. The T700T CF was immersed in the solutions for 10 s by use of a dip tank in conjunction with automatic processing equipment for continuous running of the CF through tank. The solvent was removed, and the fiber (labeling as T700M, with the diameter of 7.15 um, measured by SEM images) was dried under 110℃。
Materials
• PPEK：
聚苯醚酮，由苯醚键和酮键组成的主链芳香族聚合物。 • EL：Polyoxyethylene cater oil（表面活性剂） • NMP：diiodomethane （溶剂） • T700SC canbon fibre 12K 7.15um • acetone(丙酮）