Interfacial properties of polyurethane/nano-SiO2 modified carbon fiber epoxy resin composites
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摘要:
碳纤维表面光滑且官能团较少，不易与树脂浸润，导致界面结合强度较弱，从而大大降低了碳纤维(CF)/树脂(EP)复合材料的力学性能。大量实验证明，碳纤维表面接枝聚合物或纳米粒子可以明显提升CF/EP的界面性能，但纳米粒子在碳纤维表面的分散均匀性问题却鲜有报道。本文提出了一种采用聚氨酯(PU)低聚物对纳米SiO2表面改性的方法以及利用改性纳米SiO2对碳纤维（CF）表面改性的方法。采用异氰酸根(—NCO)封端的聚氨酯(PU)分子对纳米SiO2表面进行改性，同时采用KH550对碳纤维(CF)进行表面改性，利用—NH2与—NCO较高的反应活性，在CF和纳米SiO2粒子间通过PU分子链形成共价键连接，从而在碳纤维和树脂基体间形成“机械互锁+化学键合”双重机制的强界面结合。相较于传统的碳纤维表面接枝SiO2方法(CF-KH550-SiO2)，本文提出的改性方法(CF-KH550-PU-SiO2)不仅提升了纳米SiO2在碳纤维表面的接枝率、分散均匀性和表面能，也得复合材料的界面剪切强度提高17.3%，层间剪切强度提高11.2%，相比未改性碳纤维分别提高72.9%和47.9%。 碳纤维表面多层结构制备示意图 -
关键词:
- 碳纤维增强树脂复合材料 /
- 界面性能 /
- 纳米二氧化硅 /
- 聚氨酯
Abstract: The interfacial properties between polymer and fiber are particularly important for improving the mechanical properties of composites. In this paper, the surface of nano-SiO2 was modified by polyurethane (PU) capped by isocyanate (—NCO), and the surface of carbon fiber (CF) was modified by KH550. Bacause of the high reactivity of —NH2 and —NCO, the covalent bond was formed between CF and nano-SiO2 particles through PU molecular chain. The results show that the introduction of PU polar molecular chain improved the surface energy and wettability of CF. Compared with the CF directly grafted with nano particles by KH550(CF-KH550-SiO2), the surface energy of the CF with nano particles linked by PU(CF-KH550-PU-SiO2) molecules increased by 23.0%, and the grafting rate and dispersion uniformity of surface nano SiO2 particles also improved significantly. Compared with the untreaed CF/epoxy resin (EP) composites, the interfacial strength (IFSS) and the interlaminar shear strength (ILSS) of CF-KH550-PU-SiO2/EP composites increased by 72.9% and 47.9% respectively. Compared with the CF-KH550-SiO2/EP composites, the interfacial strength (IFSS) and the interlaminar shear strength (ILSS) of CF-KH550-PU-SiO2/EP composites increased by 17.3 % and 11.2% respectively.-
Key words:
- CF/EP composite /
- interface property /
- nano-SiO2 /
- polyurethane
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图 1 (a)纳米SiO2表面接枝聚氨酯(PU)反应过程(b)碳纤维(CF)表面多层结构制备示意图
Figure 1. (a) Reaction process of grafting polyurethane (PU) on nano-SiO2 Surface (b)Schematic illustration of multilayer structure grafted on carbon fiber (CF)
图 3 未改性纳米SiO2及PU-SiO2的TEM图及 (a, b)，两种粒子的DLS粒径曲线(c)未改性纳米SiO2及PU-SiO2的分散液(b, d)
Figure 3. TEM images of raw SiO2(a) and PU-SiO2(b), DLS curves of the synthesized SiO2(c), and photograph of the particle disperdion(d)
图 4 纳米SiO2改性前后的红外光谱图及局部放大图：未改性SiO2(a,a1,a2),改性后的SiO2(b,b1,b2)
Figure 4. FTIR spectra of raw-SiO2 (a,a1,a2)and PU-SiO2(b,b1,b2)
图 6 碳纤维表面形貌SEM和AFM照片：未改性CF(a1-a4), CF-KH550(b1-b4),CF-KH550-SiO2(c1-c4), CF-KH550-PU-SiO2(d1-d4)
Figure 6. SEM and AFM images of CFs surfaces: Untreated CF(a1-a4), CF-KH550(b1-b4), CF-KH550-SiO2(c1-c4), CF-KH550-PU-SiO2(d1-d4)
图 7 碳纤维TEM形貌及局部放大图
(a1-a2) CF; (b1-b2) CF-KH550; (c1-c3) CF-KH550-SiO2; (d1-d2) CF-KH550-PU-SiO2
Figure 7. TEM microstructures of different CFs surfaces：
(a1-a2) CF; (b1-b2) CF-KH550; (c1-c3) CF-KH550-SiO2; (d1-d2) CF-KH550- PU-SiO2
图 8 (a)碳纤维表面的静态接触角(b)碳纤维表面动态接触角 (c)碳纤维表面能
Figure 8. (a)Static contact angle of CF (b)Dynamic contact angle of CF (c)Surface energy of CF
图 9 (a)碳纤维复合材料界面剪切强度; (b)碳纤维复合材料层间剪切强度
Figure 9. (a)IFSS of composites; (b)ILSS of composites
图 10 复合材料ILSS断口形貌: (a)CF/EP; (b)CF-KH550/EP, (c)CF-KH550-SiO2/EP;(d)CF-KH550-PU-SiO2/EP
Figure 10. Cross-section morphology of composite: (a)CF/EP; (b)CF-KH550/EP, (c)CF-KH550-SiO2/EP; (d)CF-KH550-PU-SiO2/EP
图 11 复合材料ILSS断面形貌及局部放大图：
(a1-a2)CF/EP；(b1-b2)CF-KH550-SiO2/EP；(c1-c2)CF-KH550-PU-SiO2/EP
Figure 11. Cross-section of morphology of CF/EP composite:
(a1-a2)CF/EP；(b1-b2)CF-KH550-SiO2/EP；(c1-c2)CF-KH550-PU-SiO2/EP
图 12 拔脱前的CF/EP微滴及放大图(a)(b)拔脱后的CF/EP(c)及CF-KH550-PU-SiO2/EP(d)SEM图
Figure 12. SEM images of before(a) and partial enlarged view (b) removal of desized CF/EP composite, CF/EP(c) and CF-KH550-PU-SiO2/EP(d) composite after removal
图 13 不同碳纤维的界面增强机制示意图
Figure 13. Schematic diagram of the interface enhancement mechanism of different CFs
表 1 测试液的极性分量
$ {\gamma }_{l}^{p} $ 、色散分量$ {\gamma }_{l}^{d} $ 及表面能$ {\gamma }_{l} $ 单位：(mJ·m−2)Table 1. The polar component
$ {\gamma }_{l}^{p} $ , the dispersive component$ {\gamma }_{l}^{d} $ and the surface free energy$ {\gamma }_{l} $ of the testing liquids uni: (mJ·m−2)Testing liquids $ {\gamma }_{l}^{p} $ $ {\gamma }_{l}^{d} $ $ {\gamma }_{l} $ water 51 21.8 72.8 CH₂I₂ 0 50.8 50.8 
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表 2 碳纤维表面元素含量变化
Table 2. The relative elemental composition of different CFs
Samples Element/% C1 s O1 s N1 s Si2 p CF 81.33 16.01 2.33 0.33 CF-KH550 70.53 22.64 4.74 2.09 CF-KH550-SiO2 51.36 30.42 3.48 15.74 CF-KH550-PU-SiO2 29.09 42.80 6.43 21.68
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[1] 郑安呐, 胡福增. 树脂基复合材料界面结合的研究I: 界面分析及界面剪切强度的研究方法[J]. 玻璃钢/复合材料, 2004(5):12-23. doi: 10.3969/j.issn.1003-0999.2004.05.004ZHEN Anna, HU Fuzeng. Study on interfacial bonding of resin matrix composites I: Research methods of interface analysis and interface shear strength[J]. FRP/composite,2004(5):12-23(in Chinese). doi: 10.3969/j.issn.1003-0999.2004.05.004 [2] 胡福增. 材料表面与界面[J]. 上海:华东理工大学出版社, 2007:13-26.HU Fuzeng. Material surface and interface[J]. Shanghai:East China University of Science and Technology Press,2007:13-26(in Chinese). [3] 罗冬梅, 谢永东, 朱文亮. 含脱粘界面纤维增强复合材料应力传递的理论分析[J]. 纤维复合材料, 2010(4):12-16. doi: 10.3969/j.issn.1003-6423.2010.04.003LUO Dongmei, XIE Yongdong, ZHU Wenling. The Theoretical Analysis on the Stress Transfer for Fiber Teinforced Composites with Debonding Interface[J]. Ffibrous Composite,2010(4):12-16(in Chinese). doi: 10.3969/j.issn.1003-6423.2010.04.003 [4] ZhANG T, XU Y, LI H, et al. Interfacial adhesion between carbon fibers and nylon 6: Effect of fiber surface chemistry and grafting of nano-SiO2[J]. Composites Part A:Applied Science and Manufacturing,2019,121:157-168. doi: 10.1016/j.compositesa.2019.03.029 [5] WU Q, WAN Q, LIU Q, et al. Synergistic Strengthening and Toughening the Interphase of Composites by Constructing Alternating "Rigid-and-Soft" Structure on Carbon Fiber Surface[J]. Advanced Materials Interfaces,2019,6(21):132-141. [6] 陆瑶, 赵玉芬, 田荟霞. 聚丙烯腈纳米纤维膜对聚对苯撑苯并双恶唑织物增强复合材料层间剪切性能的影响[J]. 复合材料学报, 2022, 39(12):1-8.LU Yao, ZHAO Yufen, TIAN Huixia. Effect of polyacrylonitrile nanofiber membrane on interlaminar shear properties of poly-p-phenylene benzobisoxazole fabric reinforced composites[J]. Acta Materiae Compositae Sinica,2022,39(12):1-8(in Chinese). [7] HE Y X, LI Q, KUILA T, et al. Micro-crack behavior of carbon fiber reinforced thermoplastic modified epoxy composites for cryogenic applications[J]. Compos. Part B,2013,44(1):533-539. doi: 10.1016/j.compositesb.2012.03.014 [8] 胡丹. 碳纤维增强复合材料界面裂纹扩展及损伤研究 [D]. 北京: 北京化工大学, 2016.HU Dan. STUDY ON THE INTERFACIAL CRACKING AND DAMAGE OF THE CARBON REINFORCED COMPOSITE MATERIAL [D]. Beijing: Beijing University of Chemical Technology, 2016(in Chinese). [9] 黄云刚, 黄维龙, 洪浩群. 界面改性对聚丙烯-玻璃纤维复合材料力学性能影响[J]. 复合材料学报, 2022, 39(7):3157-3166.HUAN Yungang, HUANG Weilong, HONG Haoqun. Effect of interface modification on mechanical properties ofpolypropylene-glass fiber composites[J]. Acta Materiae Compositae Sinica,2022,39(7):3157-3166(in Chinese). [10] 许培俊, 吴帆, 朱真. 基于聚醚砜/氰酸酯半互穿树脂体系的碳纤维复合材料性能研究[J]. 复合材料学报, 2022, 39(6):1-10.XU Peijun, WU Fan, ZHU Zhen. Research on properties of composites based on (polyether sulfone)/cyanate ester semi-interpenetrating resin system[J]. Acta Materiae Compositae Sinica,2022,39(6):1-10(in Chinese). [11] 苏峰. 碳纤维环氧树脂界面性能研究苏峰 [D]. 哈尔滨: 哈尔滨工业大学, 2013.SU Feng. Study on the interface properties between carbon fibers and epoxy resin [D]. Harbin: Harbin Institute of Technology, 2013(in Chinese). [12] DRESCHER P, THOMAS M, BORRIS J, et al. Strengthening fibre/matrix interphase by fibre surface modification and nanoparticle incorporation into the matrix[J]. Composites Science and Technology,2013,74:60-66. doi: 10.1016/j.compscitech.2012.10.004 [13] ZHANG J, DU Z, ZOU W, et al. Zhang. MgO nanoparticles-decorated carbon fibers hybrid for improving thermal conductive and electrical insulating properties of Nylon 6 composite[J]. Composites Science and Technology,2017,148:1-8. doi: 10.1016/j.compscitech.2017.05.008 [14] MA Y, YAN C, XU H, et al. Enhanced interfacial properties of carbon fiber reinforced polyamide 6 composites by grafting graphene oxide onto fiber surface[J]. Applied Surface Science,2018,452:286-298. doi: 10.1016/j.apsusc.2018.04.274 [15] ZHANG T, SONG Y, ZHAO Y, et al. Effect of hybrid sizing with nano-SiO2 on the interfacial adhesion of carbon fibers/nylon 6 composites[J]. Colloids and Surfaces A:Physicochemical and Engineering Aspects,2018,553:125-133. [16] 李娜, 李晓屿, 刘丽. 电泳沉积氧化石墨烯的碳纤维表面改性及其增强环氧树脂复合材料界面性能[J]. 复合材料学报, 2020, 37(7):1572-1579. doi: 10.13801/j.cnki.fhclxb.20191120.001LI Na, LI Xiaoyu, LIU Li. Surface modification of carbon fiber(CF) deposited graphene oxide(GO) by electrophoresticdeposition and interfacial properties of GO-CF/epoxy composites[J]. Acta Materiae Compositae Sinica,2020,37(7):1572-1579(in Chinese). doi: 10.13801/j.cnki.fhclxb.20191120.001 [17] SHI L, SONG G, LI P, et al. Enhancing interfacial performance of epoxy resin composites via in-situ nucleophilic addition polymerization modification of carbon fibers with hyperbranched polyimidazole[J]. Composites Science and Technology,2021,201:108522. doi: 10.1016/j.compscitech.2020.108522 [18] LI N, CHENG S, WANG B, et al. Chemical grafting of graphene onto carbon fiber to produce composites with improved interfacial properties via sizing process: A step closer to industrial production[J]. Composites Science and Technology,2023,231:109822. doi: 10.1016/j.compscitech.2022.109822 [19] YU J, MENG L, FAN D, et al. The oxidation of carbon fibers through K2S2O8/AgNO3 system that preserves fiber tensile strength[J]. Composites Part B Engineering,2014,60:261-267. doi: 10.1016/j.compositesb.2013.12.037 [20] QIAN H, BISMARCK A, KALINKA G, et al. Hierarchical Composites reinforced with carbon nanotube grafted fibers: the potential assessed at the single fiber level[J]. Chemistry of Materials,2008,20(5):1862-1869. doi: 10.1021/cm702782j [21] WANG Y, MENG L, FAN L, et al. Carboxyl functionalization of carbon fibers via aryl diazonium reaction in molten urea to enhance interfacial shear strength[J]. Applied Surface Science,2016,362:341-347. doi: 10.1016/j.apsusc.2015.11.232 [22] JIANG D, XING L, LIU L, et al. Enhanced mechanical properties and anti-hydrothermal ageing behaviors of unsaturated polyester composites by carbon fibers interfaced with POSS[J]. Composites Science and Technology,2015,117:168-175. doi: 10.1016/j.compscitech.2015.05.011 [23] MA L, LI N, WU G, et al. Interfacial enhancement of carbon fiber composites by growing TiO2 nanowires onto amine-based functionalized carbon fiber surface in supercritical water[J]. Applied Surface Science,2018,433:560-567. doi: 10.1016/j.apsusc.2017.10.036 [24] 中国国家标准化管理委员会. 单向纤维增强塑料层间剪切强度试验方法: GB/T 3357[S]. 北京: 中国标准出版社, 1982.The China National Standardization Administration. Test method for interlaminar shear strength of unidirectional fiber reinforced plastics: GB/T 3357[S]. Beijing: China Stand-ards Press, 1982(in Chinese). [25] 赵立强, 南泉, 金花子. 单分散纳米二氧化硅的可控制备以及高浓度正硅酸乙酯条件下的反应机制[J]. 化学工程师, 2016(7):1-5.ZHAO Liqiang, NAN Quan, JIN Huazi. Controllable preparation of monodisperse silica and the formation mechanism under the condition of high concentration of tetra-ethyl-orthosilicate[J]. Chemical Engineer,2016(7):1-5(in Chinese). [26] 胡泊昭, 袁玉环, 马继文, 等. 改性纳米SiO2/环氧树脂热膨胀系数及冲击强度表征[J]. 航空制造技术, 2020, 63(18):75-81.HU Bozhao, YUAN Yuhuan, MA Jiwen, et al. Characterizations of coefficient of thermal expansion and impact strength of modified nano-SiO2/epoxy resin[J]. Aviation Manufacturing Technology,2020,63(18):75-81(in Chinese). [27] LIU L, YAN F, LI M, et al. A novel thermoplastic sizing containing graphene oxide functionalized with structural analogs of matrix for improving interfacial adhesion of CF/PES composites[J]. Composites Part A:Applied Science and Manufacturing,2018,114:418-428. doi: 10.1016/j.compositesa.2018.09.004 [28] JIANG D, XING L, LIU L, et al. Interfacially reinforced unsaturated polyester composites by chemically grafting different functional POSS onto carbon fibers[J]. Journal Material Chemaical A,2014,2(43):18293-18303. doi: 10.1039/C4TA04055D [29] 舒鹏. CF/改性环氧复合材料低温界面性能及液氧相容性研究 [D]. 哈尔滨: 哈尔滨工业大学, 2013.SHU Peng. Cryogenic interfacial properties and liquid oxygen compatibility of CF/modified epoxy resin [D]. Harbin: Harbin Institute of Technology, 2013(in Chinese). [30] DMITRIY A, RICHARD D, et al. Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide - ScienceDirect[J]. Carbon,2007,45(7):1558-1565. doi: 10.1016/j.carbon.2007.02.034 [31] 韩萍. 碳纤维表面多尺度结构调控及其环氧树脂复合材料界面性能研究 [D]. 青岛: 青岛大学, 2019.HAN Ping. Study on multi-scale structure control of carbon fiber surface and interfacial properties of epoxy resin composites [D]. Qingdao: Qingdao University, 2019(in Chinese). -
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