搜索

x

留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

表面氟化聚苯乙烯纳米微球提升环氧树脂绝缘特性

阴凯 郭其阳 张添胤 李静 陈向荣

引用本文:
Citation:

表面氟化聚苯乙烯纳米微球提升环氧树脂绝缘特性

阴凯, 郭其阳, 张添胤, 李静, 陈向荣

Improving insulation properties of epoxy filled with surface fluorinated polystyrene nanospheres

Yin Kai, Guo Qi-Yang, Zhang Tian-Yin, Li Jing, Chen Xiang-Rong
PDF
HTML
导出引用
  • 环氧树脂纳米复合材料在电气绝缘领域应用广泛, 通过引入纳米介质实现复合材料介电、绝缘性能的调控以满足特殊应用需求. 本文通过五氟苯乙烯与苯乙烯的共聚, 制备了表面氟化的聚苯乙烯纳米微球, 并以其为填料制备了环氧树脂复合材料. 以纯环氧树脂和填充聚苯乙烯纳米微球环氧复合材料作为参照, 研究了三种复合材料的直流电导率、介电特性、交直流击穿场强、空间电荷行为并计算了材料内部的陷阱能级. 结果表明: 填充氟化聚苯乙烯纳米微球的环氧树脂复合材料表现出优异的电学特性, 其电导率以及介电常数大幅下降、同时交直流击穿场强获得提高. 相比填充无氟聚苯乙烯纳米微球的环氧树脂, 氟化聚苯乙烯纳米微球的引入可降低材料的介电损耗, 限制空间电荷的注入, 并加深基体中的陷阱能级. 研究结果可为环氧树脂复合材料介电性能调控设计以及环氧树脂在电子封装应用提供指导.
    Epoxy resin nanocomposites are widely used in the field of electrical insulation packaging. It is of great significance to regulate the dielectric and insulation properties of composite materials by introducing nano-filler to meet special application requirements. This work proposes a chemical copolymerization method, fluorinated polystyrene nanospheres are synthesized through an addition reaction as filler, and finally the epoxy nanocomposites are prepared. The polystyrene nanospheres have a uniform size and good compatibility with the epoxy resin. The introducing of nanospheres reduces the dielectric constant of the epoxy resin composite material and increases the breakdown strength simultaneously. Although the dielectric loss increases, the composites’ imaginary part remains below 0.04 within 1 MHz frequency. In particular, the fluorinated polystyrene/epoxy composite with a mass fraction of 2% exhibits a decrease in dielectric constant and DC conductivity, while the AC breakdown strength and DC breakdown strength increase by 12.6% and 6%, respectively.The results of the pulse electro-acoustic method indicate that the charge injection of the epoxy resin filled with non-fluorinated polystyrene nanospheres is evident, while the introduction of fluorinated nanospheres significantly reduces the charge injection level. Calculations based on the depolarization process reveal that the introduction of fillers leads to an increase in trap density and depth of energy levels in the composites. Notably, the epoxy resin filled with fluorinated fillers has the deepest trap levels, providing an explanation for the improved insulation breakdown performance. The research can provide guidance for regulating dielectric properties of epoxy composites and material synthesis for the application of electrical insulation packaging .
      通信作者: 李静, lijing@hzcu.edu.cn
    • 基金项目: 中国博士后科学基金(批准号: 2023M733031)和浙江省自然科学基金重点项目(批准号: LZ22E070001)资助的课题.
      Corresponding author: Li Jing, lijing@hzcu.edu.cn
    • Funds: Project supported by the China Postdoctoral Science Foundation (Grant No. 2023M733031) and the Key Project of Natural Science Foundation of Zhejiang Province, China (Grant No. LZ22E070001).
    [1]

    Lewis T J 1994 IEEE Trans. Dielectr. Electr. Insul. 1 812Google Scholar

    [2]

    Wang Y H, Chen Z, Li J, Liu Z X, Chen R, Aung H H, Liang H C, Du B X 2024 IET Nanodielectrics 7 26Google Scholar

    [3]

    Zheng H B, Li Y H, Luo X Q, Zhang E Z, Jing J X 2023 IEEE Trans. Dielectr. Electr. Insul. 30 1884Google Scholar

    [4]

    Shen K D, Zhang X L, Qin H M, Ding C W, Nie X X, Chen D, Fan R, Xiong C X 2024 J. Mater. Sci. -Mater. Electron. 35 21Google Scholar

    [5]

    刘秀成, 杨智, 郭浩, 陈颖, 罗向龙, 陈健勇 2023 物理学报 72 168102Google Scholar

    Liu X C, Yang Z, Guo H, Chen Y, Luo X L, Chen J Y 2023 Acta Phys. Sin. 72 168102Google Scholar

    [6]

    Dong X D, Wan B Q, Qiu L, Zheng M S, Gao J F, Zha J W 2022 IET Nanodielectrics 6 76Google Scholar

    [7]

    Abusaleh B A, Elimat Z M, Alzubi R I, Juwhari H K 2023 J. Compos. Sci. 7 254Google Scholar

    [8]

    刘曰利, 赵思杰, 陈文, 周静 2022 物理学报 71 210201Google Scholar

    Liu Y L, Zhao S J, Chen W, Zhou J 2022 Acta Phys. Sin. 71 210201Google Scholar

    [9]

    任俊文, 姜国庆, 陈志杰, 魏华超, 赵莉华, 贾申利 2024 物理学报 73 027703Google Scholar

    Ren J W, Jiang G Q, Chen Z J, Wei H C, Zhao L H, Jia S L 2024 Acta Phys. Sin. 73 027703Google Scholar

    [10]

    Li M R, Shang K, Zhao J H, Jiang L H, Sun J P, Wang X, Niu H, Feng Y, An Z L, Li S T 2023 ACS Appl. Polym. Mater. 5 10226Google Scholar

    [11]

    Lü F C, Ruan H O, Song J X, Yin K, Zhan Z Y, Jiao Y F, Xie Q 2019 J. Phys. D: Appl. Phys. 52 155201Google Scholar

    [12]

    Ruan H O, Xie Q, Lü F C, Zhan Z Y, Yan J Y, Hao L C, Zhu Q S 2020 J. Phys. D: Appl. Phys. 53 145204Google Scholar

    [13]

    杨国清, 刘阳, 戚相成, 王德意, 王闯, 曾庆文 2021 高电压技术 47 3144Google Scholar

    Yang G Q, Liu Y, Qi X C, Wang D Y, Wang C, Zeng Q W 2021 High Voltage Eng. 47 3144Google Scholar

    [14]

    Duan Q J, Song Y Z, Shao S, Yin G H, Ruan H O, Xie Q 2023 Plasma Sci. Technol. 25 104004Google Scholar

    [15]

    Zhang C, Ma Y Y, Kong F, Yan P, Chang C, Shao T 2019 Surf. Coat. Technol. 362 1Google Scholar

    [16]

    查俊伟, 查磊军, 郑明胜 2023 物理学报 72 018401Google Scholar

    Zha J W, Zha L J, Zheng M S 2023 Acta Phys. Sin. 72 018401Google Scholar

    [17]

    Wei W C, Chen H Q, Zha J W, Zhang Y Y 2023 Front. Chem. Sci. Eng. 17 991Google Scholar

    [18]

    Liu Y P, Li L, Liu H C, Zhang M J, Liu A J, Liu L, Tang L, Wang G L, Zhou S S 2020 Compos. Sci. Technol. 200 108418Google Scholar

    [19]

    Liu Y Y, Yao R X, Tong Y J, Lu Y Q, Guo Q Y 2023 Polym. Bull. DOI: 10.1007/s00289-023-05120-w

    [20]

    高铭泽, 张沛红 2016 物理学报 65 247802Google Scholar

    Gao M Z, Zhang P H 2016 Acta Phys. Sin. 65 247802Google Scholar

    [21]

    Zhu G, Chen X, Hong Z, Awais M, Paramane A, Wang X, Zhang J Q, Liu W 2022 IEEE Trans. Appl. Supercond. 32 1Google Scholar

    [22]

    Turgeman R, Gershevitz O, Palchik O, Deutsch M, Ocko B M, Gedanken A, Sukenik C N 2004 Cryst. Growth 4 169Google Scholar

    [23]

    Shang X J, Zhu Y M, Li Z H 2017 Appl. Surf. Sci. 394 169Google Scholar

    [24]

    Su Y C, Chang F C 2003 Polymer 44 7989Google Scholar

    [25]

    陈季丹, 刘子玉 1982 电介质物理学(北京: 机械工业出版社) 第94页

    Chen J D, Liu Z Y 1982 Dielectric Physics (Beijing: China Machine Press) p94

    [26]

    Lin Y, Liu Y, Cao B, Xue J, Wang L, Wang J, Ding L 2023 High Voltage 8 283Google Scholar

    [27]

    周远翔, 黄猛, 陈维江, 孙清华, 沙彦超, 张灵 2013 高电压技术 39 1304Google Scholar

    Zhou Y X, Huang M, Chen W J, Sun Q H, Sha Y C, Zhang L 2013 High Voltage Eng. 39 1304Google Scholar

    [28]

    Simmons J G, Tam M C 1973 Phys. Rev. B 7 3706Google Scholar

    [29]

    Xie Q, Yin G H, Duan Q J, Zhong Y Y, Xie J, Fu K X, Wang P 2023 Polym. Compos. 44 6071Google Scholar

    [30]

    Chen X, Yu J, Yu L, Zhou H 2018 IEEE Access 7 8226Google Scholar

  • 图 1  PS, F-PS纳米微球及表面C, F元素分布 (a), (b)不同窗口尺寸下的PS纳米微球形貌; (c) PS纳米微球表面C元素分布; (d) PS纳米微球C和F元素含量; (e) F-PS纳米微球形貌; (f), (g) F-PS纳米微球表面C和F元素分布; (h) F-PS纳米微球表面C和F元素含量

    Fig. 1.  PS and F-PS nanospheres and C, F element distribution: (a), (b) Morphology of PS nanospheres at different zoom scale; (c) distribution of C element on the surface of PS nanospheres; (d) the content of C and F elements in PS nanospheres; (e) morphology of F-PS nanospheres; (f), (g) distribution of C and F elements on the surface of F-PS nanospheres; (h) content of C and F elements in F-PS nanospheres.

    图 2  氟化前后的PS纳米微球的FT-IR图谱.

    Fig. 2.  FT-IR spectra of PS and F-PS nanospheres.

    图 3  (a) Pure EP、(b)填充PS和(c) F-PS纳米微球后环氧树脂复合材料断面形貌

    Fig. 3.  Cross-section morphology of (a) Pure EP, (b) filled with PS, and (c) F-PS nanospheres.

    图 4  (a) Pure EP, (b) PS-EP和(c) F-PS-EP的FT-IR图谱

    Fig. 4.  FT-IR spectra of (a) Pure EP, (b) PS-EP, and (c) F-PS-EP composites.

    图 5  Pure EP, PS-EP和F-PS-EP在不同场强下的电导率

    Fig. 5.  Conductivity of Pure EP, PS-EP, F-PS-EP composites at different applied electric fields.

    图 6  复合材料宽频介电常数(a)实部ε'和虚部ε''; (b) Pure EP, (c) 2% PS-EP和(d) 2% F-PS-EP介电虚部弛豫响应分解

    Fig. 6.  Broadband dielectric spectroscopy (a) real part ε' and imaginary part ε'' of composites; the fitting data of broadband dielectric spectroscopy imaginary part ε'' corresponds to (b) Pure EP, (c) 2% PS-EP, (d) 2% F-PS-EP composites.

    图 7  Pure EP, PS-EP和F-PS-EP的(a)交流击穿场强、(b)直流击穿场强的韦布尔概率分布和(c)交、直流平均击穿场强

    Fig. 7.  Weibull probability distribution for (a) AC, (b) DC breakdown strength and (c) average AC, DC breakdown strength of Pure EP, PS-EP and F-PS-EP composites.

    图 8  (a) Pure EP, (b) 2% PS-EP和(c) 2% F-PS-EP的空间电荷分布随时间的变化; (d) 纯环氧树脂、(e) 2% PS-EP和(f) 2% F-PS-EP的空间电场分布随时间的变化

    Fig. 8.  Space charge distribution of (a) Pure EP, (b) 2% PS-EP, and (c) 2% F-PS-EP with time; space electric field distribution of (d) pure EP, (e) 2% PS-EP, and (f) 2% F-PS-EP with time.

    图 9  (a) Pure EP, PS-EP and F-PS-EP平均电荷密度随时间的衰减和(b)陷阱能级

    Fig. 9.  (a) Decay of average charge density with time and (b) trap energy levels in Pure EP, PS-EP, and F-PS-EP.

    表 1  Pure EP, PS-EP和F-PS-EP韦布尔概率分布参数

    Table 1.  Weibull distribution parameters for Pure EP, PS-EP and F-PS-EP.

    复合材料 AC DC
    μ σ μ σ
    Pure EP 67.45 5.00 187.20 24.63
    2% PS-EP 74.00 4.02 190.41 32.18
    2% F-PS-EP 75.54 3.99 198.59 25.20
    下载: 导出CSV
  • [1]

    Lewis T J 1994 IEEE Trans. Dielectr. Electr. Insul. 1 812Google Scholar

    [2]

    Wang Y H, Chen Z, Li J, Liu Z X, Chen R, Aung H H, Liang H C, Du B X 2024 IET Nanodielectrics 7 26Google Scholar

    [3]

    Zheng H B, Li Y H, Luo X Q, Zhang E Z, Jing J X 2023 IEEE Trans. Dielectr. Electr. Insul. 30 1884Google Scholar

    [4]

    Shen K D, Zhang X L, Qin H M, Ding C W, Nie X X, Chen D, Fan R, Xiong C X 2024 J. Mater. Sci. -Mater. Electron. 35 21Google Scholar

    [5]

    刘秀成, 杨智, 郭浩, 陈颖, 罗向龙, 陈健勇 2023 物理学报 72 168102Google Scholar

    Liu X C, Yang Z, Guo H, Chen Y, Luo X L, Chen J Y 2023 Acta Phys. Sin. 72 168102Google Scholar

    [6]

    Dong X D, Wan B Q, Qiu L, Zheng M S, Gao J F, Zha J W 2022 IET Nanodielectrics 6 76Google Scholar

    [7]

    Abusaleh B A, Elimat Z M, Alzubi R I, Juwhari H K 2023 J. Compos. Sci. 7 254Google Scholar

    [8]

    刘曰利, 赵思杰, 陈文, 周静 2022 物理学报 71 210201Google Scholar

    Liu Y L, Zhao S J, Chen W, Zhou J 2022 Acta Phys. Sin. 71 210201Google Scholar

    [9]

    任俊文, 姜国庆, 陈志杰, 魏华超, 赵莉华, 贾申利 2024 物理学报 73 027703Google Scholar

    Ren J W, Jiang G Q, Chen Z J, Wei H C, Zhao L H, Jia S L 2024 Acta Phys. Sin. 73 027703Google Scholar

    [10]

    Li M R, Shang K, Zhao J H, Jiang L H, Sun J P, Wang X, Niu H, Feng Y, An Z L, Li S T 2023 ACS Appl. Polym. Mater. 5 10226Google Scholar

    [11]

    Lü F C, Ruan H O, Song J X, Yin K, Zhan Z Y, Jiao Y F, Xie Q 2019 J. Phys. D: Appl. Phys. 52 155201Google Scholar

    [12]

    Ruan H O, Xie Q, Lü F C, Zhan Z Y, Yan J Y, Hao L C, Zhu Q S 2020 J. Phys. D: Appl. Phys. 53 145204Google Scholar

    [13]

    杨国清, 刘阳, 戚相成, 王德意, 王闯, 曾庆文 2021 高电压技术 47 3144Google Scholar

    Yang G Q, Liu Y, Qi X C, Wang D Y, Wang C, Zeng Q W 2021 High Voltage Eng. 47 3144Google Scholar

    [14]

    Duan Q J, Song Y Z, Shao S, Yin G H, Ruan H O, Xie Q 2023 Plasma Sci. Technol. 25 104004Google Scholar

    [15]

    Zhang C, Ma Y Y, Kong F, Yan P, Chang C, Shao T 2019 Surf. Coat. Technol. 362 1Google Scholar

    [16]

    查俊伟, 查磊军, 郑明胜 2023 物理学报 72 018401Google Scholar

    Zha J W, Zha L J, Zheng M S 2023 Acta Phys. Sin. 72 018401Google Scholar

    [17]

    Wei W C, Chen H Q, Zha J W, Zhang Y Y 2023 Front. Chem. Sci. Eng. 17 991Google Scholar

    [18]

    Liu Y P, Li L, Liu H C, Zhang M J, Liu A J, Liu L, Tang L, Wang G L, Zhou S S 2020 Compos. Sci. Technol. 200 108418Google Scholar

    [19]

    Liu Y Y, Yao R X, Tong Y J, Lu Y Q, Guo Q Y 2023 Polym. Bull. DOI: 10.1007/s00289-023-05120-w

    [20]

    高铭泽, 张沛红 2016 物理学报 65 247802Google Scholar

    Gao M Z, Zhang P H 2016 Acta Phys. Sin. 65 247802Google Scholar

    [21]

    Zhu G, Chen X, Hong Z, Awais M, Paramane A, Wang X, Zhang J Q, Liu W 2022 IEEE Trans. Appl. Supercond. 32 1Google Scholar

    [22]

    Turgeman R, Gershevitz O, Palchik O, Deutsch M, Ocko B M, Gedanken A, Sukenik C N 2004 Cryst. Growth 4 169Google Scholar

    [23]

    Shang X J, Zhu Y M, Li Z H 2017 Appl. Surf. Sci. 394 169Google Scholar

    [24]

    Su Y C, Chang F C 2003 Polymer 44 7989Google Scholar

    [25]

    陈季丹, 刘子玉 1982 电介质物理学(北京: 机械工业出版社) 第94页

    Chen J D, Liu Z Y 1982 Dielectric Physics (Beijing: China Machine Press) p94

    [26]

    Lin Y, Liu Y, Cao B, Xue J, Wang L, Wang J, Ding L 2023 High Voltage 8 283Google Scholar

    [27]

    周远翔, 黄猛, 陈维江, 孙清华, 沙彦超, 张灵 2013 高电压技术 39 1304Google Scholar

    Zhou Y X, Huang M, Chen W J, Sun Q H, Sha Y C, Zhang L 2013 High Voltage Eng. 39 1304Google Scholar

    [28]

    Simmons J G, Tam M C 1973 Phys. Rev. B 7 3706Google Scholar

    [29]

    Xie Q, Yin G H, Duan Q J, Zhong Y Y, Xie J, Fu K X, Wang P 2023 Polym. Compos. 44 6071Google Scholar

    [30]

    Chen X, Yu J, Yu L, Zhou H 2018 IEEE Access 7 8226Google Scholar

  • [1] 任俊文, 姜国庆, 陈志杰, 魏华超, 赵莉华, 贾申利. 氮化硼纳米管表面结构设计及其对环氧复合电介质性能调控机理. 物理学报, 2024, 73(2): 027703. doi: 10.7498/aps.73.20230708
    [2] 刘秀成, 杨智, 郭浩, 陈颖, 罗向龙, 陈健勇. 金刚石/环氧树脂复合物热导率的分子动力学模拟. 物理学报, 2023, 72(16): 168102. doi: 10.7498/aps.72.20222270
    [3] 孟菁饴, 卢红伟, 马世乐, 张嘉奇, 何富民, 苏伟涛, 赵晓东, 田婷, 王翼, 邢誉. 功能化原子力显微镜在纳米电介质材料性能研究中的应用进展. 物理学报, 2022, 71(24): 240701. doi: 10.7498/aps.71.20221462
    [4] 杨如霞, 卢玉明, 曾丽竹, 张禄佳, 李冠男. 钆掺杂对0.7BiFe0.95Ga0.05O3-0.3BaTiO3陶瓷的结构、介电性能和多铁性能的影响. 物理学报, 2020, 69(10): 107701. doi: 10.7498/aps.69.20200175
    [5] 林生军, 黄印, 谢东日, 闵道敏, 王威望, 杨柳青, 李盛涛. 环氧树脂高温分子链松弛与玻璃化转变特性. 物理学报, 2016, 65(7): 077701. doi: 10.7498/aps.65.077701
    [6] 茹佳胜, 闵道敏, 张翀, 李盛涛, 邢照亮, 李国倡. 直流电晕充电下环氧树脂表面电位衰减特性的研究. 物理学报, 2016, 65(4): 047701. doi: 10.7498/aps.65.047701
    [7] 冯奇, 李梦凯, 唐海通, 王晓东, 高忠民, 孟繁玲. 石墨烯/聚乙烯醇/聚偏氟乙烯基纳米复合薄膜的介电性能. 物理学报, 2016, 65(18): 188101. doi: 10.7498/aps.65.188101
    [8] 赵学童, 廖瑞金, 李建英, 王飞鹏. 直流老化对CaCu3Ti4O12陶瓷介电性能的影响. 物理学报, 2015, 64(12): 127701. doi: 10.7498/aps.64.127701
    [9] 周静, 刘存金, 李儒, 陈文. 异质界面对Ca(Mg1/3Nb2/3)O3/CaTiO3叠层薄膜结构和介电性能的影响. 物理学报, 2012, 61(6): 067401. doi: 10.7498/aps.61.067401
    [10] 李智敏, 施建章, 卫晓黑, 李培咸, 黄云霞, 李桂芳, 郝跃. 掺铝3C-SiC电子结构的第一性原理计算及其微波介电性能. 物理学报, 2012, 61(23): 237103. doi: 10.7498/aps.61.237103
    [11] 陈超, 江向平, 卫巍, 李小红, 魏红斌, 宋福生. (K0.45Na0.55)NbO3无铅压电晶体的生长形态与介电性能研究. 物理学报, 2011, 60(10): 107704. doi: 10.7498/aps.60.107704
    [12] 丁南, 唐新桂, 匡淑娟, 伍君博, 刘秋香, 何琴玉. 锰掺杂对Ba(Zr, Ti)O3陶瓷压电与介电性能的影响. 物理学报, 2010, 59(9): 6613-6619. doi: 10.7498/aps.59.6613
    [13] 姚俊兰, 安振连, 毛明军, 张冶文, 夏钟福. 等温结晶化条件对氟化孔洞聚丙烯膜电荷稳定性的显著影响. 物理学报, 2010, 59(9): 6508-6513. doi: 10.7498/aps.59.6508
    [14] 赵苏串, 李国荣, 张丽娜, 王天宝, 丁爱丽. Na0.25K0.25Bi0.5TiO3无铅压电陶瓷的介电特性研究. 物理学报, 2006, 55(7): 3711-3715. doi: 10.7498/aps.55.3711
    [15] 黄集权, 洪兰秀, 韩高荣, 翁文剑, 杜丕一. Fe-Ni-BaTiO3复合材料的介电行为及其机理研究. 物理学报, 2006, 55(7): 3664-3669. doi: 10.7498/aps.55.3664
    [16] 曾 涛, 董显林, 毛朝梁, 梁瑞虹, 杨 洪. 孔隙率及晶粒尺寸对多孔PZT陶瓷介电和压电性能的影响及机理研究. 物理学报, 2006, 55(6): 3073-3079. doi: 10.7498/aps.55.3073
    [17] 马建华, 孙璟兰, 孟祥建, 林 铁, 石富文, 褚君浩. SrTiO3金属-绝缘体-半导体结构的介电与界面特性. 物理学报, 2005, 54(3): 1390-1395. doi: 10.7498/aps.54.1390
    [18] 张丽娜, 赵苏串, 郑嘹赢, 李国荣, 殷庆瑞. 复合层状Bi7Ti4NbO21铁电陶瓷的结构与介电和压电性能研究. 物理学报, 2005, 54(5): 2346-2351. doi: 10.7498/aps.54.2346
    [19] 惠荣, 朱骏, 卢网平, 毛翔宇, 羌锋, 陈小兵. La掺杂诱发层状钙钛矿型铁电体弛豫性相变的介电研究. 物理学报, 2004, 53(1): 276-281. doi: 10.7498/aps.53.276
    [20] 刘鹏, 边小兵, 张良莹, 姚熹. (PbBa)(Zr,Sn,Ti)O_3反铁电/弛豫型铁电相界陶瓷的相变与介电、热释电性质. 物理学报, 2002, 51(7): 1628-1633. doi: 10.7498/aps.51.1628
计量
  • 文章访问数:  1717
  • PDF下载量:  59
  • 被引次数: 0
出版历程
  • 收稿日期:  2024-01-31
  • 修回日期:  2024-03-30
  • 上网日期:  2024-04-09
  • 刊出日期:  2024-06-20

/

返回文章
返回