Effect of gradient structure on the interface failure of bamboo bundle fiber composite material
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摘要: 为研究竹材梯度结构对竹束纤维复合材料性能的影响,以竹束纤维(BF)为增强相,环氧树脂-甲基四氢邻苯二甲酸酐(EP-MeTHPA)体系为基体相,采用热压成型制备竹束纤维增强环氧树脂-甲基四氢邻苯二甲酸酐复合材料体系(BF/EP-MeTHPA)。通过改变BF单元—竹青侧束纤维(BF-GS)和竹黄侧束纤维(BF-YS),研究梯度结构对BF/EP-MeTHPA界面失效的影响。在分析复合材料力学性能的基础上,通过动态热机械分析(DMA)、原位加载、FTIR等纳、微观试验手段,对纤维-树脂结合状态、界面微区力学、热分析和宏观力学表征等进行研究。实验结果表明,由于BF-GS中纤维含量与强度较高,在EP-MeTHPA体系中的增强效果与分布均匀性优于BF-YS,弯曲呈现韧性阶梯状破坏;但其浸润性与界面性能却低于竹黄侧束纤维增强环氧树脂-甲基四氢邻苯二甲酸酐复合材料体系(BF-YS/EP-MeTHPA)。通过对竹材结构进行观察,发现BF-YS残留了更多的薄壁细胞,粗糙表面有利于EP的浸润与黏附,因此在接触角测试中,BF-YS的浸润力约为BF-GS的60%。FTIR显示,MeTHPA可与BF羟基反应生成新的酯键,使得BF与EP-MeTHPA体系形成化学键,提高界面稳定性,而BF-YS中非结晶区的暴露使其极性更强(106.5 mN/m),各特征峰相对面积变化量也大于BF-GS,更容易形成化学键合,其稳定性也会提高。Abstract: In order to study the effect of bamboo gradient structure on the properties of bamboo bundle fiber composites, bamboo bundle fiber (BF) as the enhanced phase, epoxy resin (EP)-methyl tetrahydrophthalic anhydride (MeTHPA) system is the matrix phase, BF/EP-MeTHPA composite was prepared by thermopress molding. By changing the BF unit: yellow side (BF-YS) and green side bundle fiber (BF-GS), the effect of natural structure on the failure of interface of BF/EP composite was studied. Based on the mechanical properties of composites, through nano and micro test means such as dynamic thermomechanical analysis (DMA), in situ SEM and FTIR, the state of BF/EP-MeTHPA, interface microregion, thermal analysis and macromechanical characterization were studied. The experimental results show that due to the high fiber content and strength in BF-GS, the enhancement effect and distribution uniformity in epoxy system is better than BF-YS. But the permeability and interface performance are lower than bamboo bundle fiber of yellow side/epoxy resin-MeTHPA (BF-YS/EP-MeTHPA). Through the observation of the bamboo structure, it is found that BF-YS remains more parenchyma cells, and the rough surface favors the infiltration and adhesion of EP, so the infiltration force of BF-YS is about 60% in the contact angle test of BF-GS. FTIR shows that MeTHPA can react with BF hydroxyl groups to generate new ester bonds, making the chemical bond between BF and EP-MeTHPA system to improve the interface stability, while the exposure of the non-crystalline area of BF-YS makes its polarity stronger (106.5 mN/m), the relative area variation of the characteristic peaks is greater than BF-GS, easier to form, and the stability will also improve.
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Key words:
- bamboo fiber /
- gradient structure /
- natural structure /
- composite /
- interface /
- failure mechanism
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图 1 竹束纤维(BF)制备工艺:(a) 竹样;(b) 竹条;(c) 竹麻;(d) 竹青侧束纤维(BF-GS);(e) 竹黄侧束纤维(BF-YS);(f) 竹材横截面结构;竹青侧 (g) 和竹黄侧 (h) 的SEM图像
Figure 1. Preparation process of bamboo bundle fiber (BF): (a) Bamboo samples; (b) Bamboo strips; (c) Bamboo fiber bundles; (d) Yellow side (BF-YS); (e) Green side bundle fiber (BF-GS); (f) Bamboo cross-sectional structure; SEM images of GS (g) and YS (h)
表 1 BF/EP-MeTHPA种类与组分质量百分比
Table 1. Types and mass percentage of BF/EP-MeTHPA composites
Types EP-MeTHPA/wt% BF-YS/wt% BF-GS/wt% EP-MeTHPA 100 0 0 BF-YS/EP-MeTHPA 55 45 0 BF-GS/EP-MeTHPA 55 0 45 表 2 BF/EP-MeTHPA的弯曲力学性能
Table 2. Bending properties of BF/EP-MeTHPA
Types Modulus of elasticity/GPa Modulus of rupture/MPa EP-MeTHPA 3.9±0.4 (A) 54.8±8.1 (A) BF-YS/EP-MeTHPA 18.9±2.7 (B) 304.8±31.4 (A) BF-GS/EP-MeTHPA 23.7±2.0 (C) 356.1±45.0 (B) Note: There are significant differences at the 0.05 level of Duncan test and groups with the same letters do not differ statistically. 表 3 BF接触角与表面能
Table 3. Contact angle and surface energy of BF
Contact angle/(°) Surface tension/
(mN·m−1)Water Ethylene glycol Polar part Disperse part BF-GS 39.85 28.54 91.9 0.2 BF-YS 34.05 34.21 106.5 0.7 表 4 MeTHPA处理BF前后的FTIR图谱特征峰面积比
Table 4. FTIR spectroscopy characteristic peak area ratio before and after treatment of BF with MeTHPA
Area ratio —CH2 —C=O —OH Range 3010-2810 1680-1790 3680-3010 BF-GS 17.89 0.65(0.04) 267.62(14.96) BF-GS/MeTHPA 12.85 4.71(0.37) 189.38(14.74) BF-YS 17.71 0.34(0.02) 241.25(13.63) BF-YS/MeTHPA 21.42 12.31(0.58) 204.43(9.55) -
[1] ZHUO P S, CHANG H F, SHENG X H, et al. Tensile properties of moso bamboo (phyllostachys pubescens) and its components with respect to its fiber-reinforced composite structure[J]. Wood Science and Technology,2010,44(4):655-666. doi: 10.1007/s00226-009-0290-1 [2] WANG C, YU X, SMITH L M, et al. Interfacial properties of bamboo fiber-reinforced high-density polyethylene composites by different methods for adding nano calcium carbonate[J]. Polymers,2017,9(11):587. doi: 10.3390/polym9110587 [3] HUANG J K, YOUNG W B. The mechanical, hygral, and interfacial strength of continuous bamboo fiber reinforced epoxy composites[J]. Composites,2019,166(1):272-283. [4] ULRIKE G K, HAO B, EDUARDO S, et al. Bioinspired structural materials[J]. Nature Materials,2015,14(1):23-36. doi: 10.1038/nmat4089 [5] WANG X, YUAN Z, ZHAN X, et al. Multi-scale characterization of the thermal-mechanically isolated bamboo fiber bundles and its potential application on engineered composites[J]. Construction and Building Materials,2020,262(10):120866. [6] LEE C H, YANG T H, CHENG Y W, et al. Effects of thermal modification on the surface and chemical properties of moso bamboo[J]. Construction and Building Materials,2018,178:59-71. doi: 10.1016/j.conbuildmat.2018.05.099 [7] WEI X, ZHOU H Y, CHEN F M, et al. Bending flexibility of moso bamboo (phyllostachys edulis) with functionally graded structure[J]. Materials (Basel, Switzerland),2019,12(12):2007. doi: 10.3390/ma12122007 [8] AK H P S, BHAT I, JAWAID M, et al. Bamboo fibre reinforced biocomposites: A review[J]. Materials and Design,2012,42:353-368. doi: 10.1016/j.matdes.2012.06.015 [9] 江泽慧, 孙正军, 任海青. 先进生物质复合材料在风电叶片中的应用[J]. 复合材料学报, 2006, 23(3): 127-129.JIANG Zehui, SUN Zhengjun, REN Haiqing. Application of advanced bio-composites in wind blades[J]. Acta Materiae Compositae Sinica, 2006, 23(3): 127-129(in Chinese). [10] 孙正军, 程强, 江泽慧. 竹质工程材料的制造方法与性能[J]. 复合材料学报, 2008, 25(1):80-83. doi: 10.3321/j.issn:1000-3851.2008.01.014SUN Zhengjun, CHENG Qiang, JIANG Zehui. Processing and properties of engineering bamboo products[J]. Acta Materiae Compositae Sinica,2008, 25(1):80-83(in Chinese). doi: 10.3321/j.issn:1000-3851.2008.01.014 [11] KU H, WANG H, PATTARACHAIYAKOOP N, et al. A review on the tensile properties of natural fiber reinforced polymer composites[J]. Composites Part B: Engineering,2011,42(4):856-873. doi: 10.1016/j.compositesb.2011.01.010 [12] KABIR M M, WANG H, LAU K T, et al. Chemical treatments on plant-based natural fiber reinforced polymer compo-sites: An overview[J]. Composites Part B: Engineering,2012,43(7):2883-2892. doi: 10.1016/j.compositesb.2012.04.053 [13] FIORE V, BELLA G D, VALENZA A. The effect of alkaline treatment on mechanical properties of kenaf fibers and their epoxy composites[J]. Composites Part B: Engineering,2015,68(1):14-21. [14] MITTALV, SAINI R, SINHA S. Natural fiber-mediated epoxy composites—A review[J]. Composites Part B: Engi-neering,2016,99(8):425-435. doi: 10.1016/j.compositesb.2016.06.051 [15] SAHA P, MANNA S, CHOWDHURY S R, et al. Enhancement of tensile strength of lignocellulosic jute fibers by alkali-steam treatment[J]. Bioresource Technology,2010,101(9):3182-3187. doi: 10.1016/j.biortech.2009.12.010 [16] 中国国家标准化管理委员会. 人造板及饰面人造板理化性能试验方法: GB/T17657—2013[S]. 北京: 中国标准出版社, 2013.Standardization Administration of the People’s Republic of China. Test methods of evaluating the properties of wood-based panels and surface decorated wood-based panels: GB/T 17657—2013[S]. Beijing: China Standards Press, 2013(in Chinese). [17] 王戈, 陈红, 余雁, 等. 竹纤维细胞水平的物理力学性能精细表征技术[J]. 北京林业大学学报, 2011, 33(4):143-148.WANG Ge, CHEN Hong, YU Yan, et al. Fine characterization techniques of physical and mechanical properties of bamboo fiber in cell level[J]. Journal of Beijing Forestry University,2011,33(4):143-148(in Chinese). [18] American Society for Testing and Materials International. Standard test method for glass transition temperature (DMA Tg) of polymer matrix composites by dynamic mechanical analysis (DMA): D7028-07[S]. West Conshohocken: American Society for Testing and Materials, 2008. [19] 王翠翠, 程海涛, 羡瑜, 等. 纳米CaCO3增强竹浆纤维/环氧树脂复合材料的动态力学性能[J]. 农业工程学报, 2017, 3(6):281-287. doi: 10.11975/j.issn.1002-6819.2017.06.036WANG Cuicui, CHENG Haitao, XIAN Yu, et al. Improving dynamic mechanical property of bamboo pulp fiber reinforced epoxy resin composite treated by nano calcium carbonate[J]. Transactions of the Chinese Society of Agricultural Engineering,2017,3(6):281-287(in Chinese). doi: 10.11975/j.issn.1002-6819.2017.06.036 [20] 程海涛, 王戈, 谌晓梦, 等. 光学法和力学法测定单根纤维接触角及相关性分析[J]. 林产工业, 2013, 40(1):49-51. doi: 10.3969/j.issn.1001-5299.2013.01.014CHENG Haitao, WANG Ge, SHEN Xiaomeng, et al. Single fiber contact angle measured by different methods and correlation analysis[J]. China Forest Products Industry,2013,40(1):49-51(in Chinese). doi: 10.3969/j.issn.1001-5299.2013.01.014 [21] HODGSON K T, BERG J C. Dynamic wettability properties of single wood pulp fibers and their relationship to absorbency[J]. Wood & Fiber Science,1988,20(1):3-17. [22] FUENTES C A, TRAN L Q, DUPONT G C, et al. Wetting behaviour and surface properties of technical bamboo fibres[J]. Colloid Surface A,2011,380(1-3):89-99. [23] QIU S, FUENTES C A, ZHANG D X, et al. Wettability of a single carbon fiber[J]. Langmuir,2016,32(38):9697-9705. doi: 10.1021/acs.langmuir.6b02072 [24] XIE Y J, CALLUM A S H, XIAO Z F, et al. Silane coupling agents used for natural fiber/polymer composites: A review[J]. Composites Part A: Applied Science and Manufacturing,2010,41(7):806-819. doi: 10.1016/j.compositesa.2010.03.005 [25] PAUL S A, JOSEPH K, MATHEW G D G, et al. Influence of polarity parameters on the mechanical properties of composites from polypropylene fiber and short banana fiber[J]. Composites Part A: Applied Science and Manufacturing,2010,41(10):1380-1387. doi: 10.1016/j.compositesa.2010.04.015 [26] FUENTES C A, TRAN L, HELLEMONT M V, et al. Effect of physical adhesion on mechanical behaviour of bamboo fibre reinforced thermoplastic composites[J]. Colloids & Surfaces A: Physicochemical & Engineering Aspects,2013,418:7-15. [27] KASIVISWANATHAN S, SANTHANAM K, KUMARAVEL A. Evaluation of mechanical properties of natural hybrid fibers, reinforced polyester composite materials[J]. Carbon-Science and Technology,2015,7(4):43-49. [28] XIONG Z, CHAO L, MA S, et al. The properties of poly(lactic acid)/starch blends with a functionalized plant oil: Tung oil anhydride[J]. Carbohydrate Polymers,2013,95(1):77-84. doi: 10.1016/j.carbpol.2013.02.054