Accelerated aging behavior of glass fiber reinforced methacrylate-based cured-in-place-pipe lining in seawater and sulfuric acid
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摘要:
原位固化管道(Cured-in-place-pipe，CIPP)内衬用于修复被生物硫酸腐蚀的排水管道，也用于市政排海管道。而玻璃纤维/甲基丙烯酸酯基复合材料用于CIPP内衬，在硫酸和海水环境下的耐久性尚不明确。设计了0.5%硫酸、模拟海水与高温(80℃)加速相耦合的老化实验，以纯水作为对照，基于吸水测试、三点弯曲测试、接触角分析、SEM和FTIR等表征测试方法，研究了玻璃纤维/甲基丙烯酸酯基CIPP内衬的老化行为。结果显示：0.5%硫酸、模拟海水和纯水加速老化
1440 h后，弯曲强度分别下降了57.9%、58.4%和57.4%，而弯曲模量没有明显下降；酯键水解生成的羟基部分被氧化为羰基，使树脂老化后颜色发黄；硫酸劣化了树脂表面使润湿性降低，也通过腐蚀表面玻璃纤维促进了水分扩散；海水中盐分析出结晶阻碍了水分扩散，也严重破坏了材料表面的树脂层，使润湿性增强。提高CIPP内衬的耐久性，重点应该抑制水分扩散劣化界面。可为甲基丙烯酸酯用于CIPP修复材料的耐久性评估提供参考依据。Abstract:Cured-in-place-pipe (CIPP) lining is used to repair drainage pipes corroded by biological sulfuric acid and is also used in municipal sea drainage pipes. However, the durability of glass fiber reinforced methacrylate-based composite materials used in CIPP lining in sulfuric acid and seawater environments is unclear. This study established two aging conditions: 0.5% sulfuric acid and simulated seawater, with the temperature of 80℃ to accelerate aging. Pure water was used as a control. Characterization and testing methods such as water absorption test, three-point bending test, contact angle analysis, SEM, and FTIR were used for the study to evaluate the aging behavior of glass fiber reinforced methacrylate-based CIPP lining. The results show that the bending strength decreases by 57.9%, 58.4%, and 57.4% respectively, after accelerated aging in 0.5% sulfuric acid, simulated seawater, and pure water for
1440 h. While the bending modulus does not show a significant decrease. The hydroxyl group generated by the hydrolysis of the ester bond is partially oxidized to a carbonyl group, causing the resin to turn yellow after aging. Sulfuric acid deteriorates the resin surface and reduces the wettability, and also promotes water diffusion by corroding the surface glass fiber. The crystallization of salt in seawater hinders the diffusion of water and severely damages the resin layer on the material surface, leading to enhanced wettability. To enhance CIPP lining durability, efforts should focus on inhibiting moisture diffusion and degradation at the interface. This study can provide a reference basis for the durability evaluation of methacrylate used in CIPP repair materials. -
随着电子元器件小型化、集成化和多功能化的发展，要求基础树脂能够及时传输元器件在使用过程中产生的热量，以避免热沉积引发火灾危险的问题[1-2]。环氧树脂(EP)因其优异的粘接、耐化学腐蚀和绝缘性能而被广泛用于层压电路板、电子元件封装和热界面材料的基础树脂[3-5]。但EP本身易燃并且导热系数也非常低，约0.2 W·m−1·K−1，使其应用受限[6-8]。因此，对EP进行有效阻燃和导热改性至关重要。
石墨烯具有声子传热散射小、传热效率高等优点，导热系数高达5000 W·m−1·K−1，成为复合型导热高分子材料制备的候选填料[9]，其二维层状结构具有较强的气体阻隔作用、较高的热稳定性和较大的比表面吸附能力，有利于协同阻燃[10]。石墨烯及其衍生物中，石墨烯纳米片(GNPs) 在复合材料中应用占比最大，机械剥离法比氧化还原法成本低、易制备、污染少、缺陷程度低[11-12]。报道指出[13-15]，以三聚氰胺(MN)为助剥离剂，利用
π -π 相互作用，通过球磨微粉石墨可获得非共价功能化GNPs的优点是既不破坏其表面疏水性，也不产生缺陷结构[15-16]。由此，能够改善GNPs与树脂基体的界面相互作用，更好发挥其导热性能。同时，多层石墨烯显示了比单层石墨烯更好的导热效果，且与未完全剥离的微粉石墨等导热填料可以协同形成更有效的导热网络[17-18]。三嗪化合物MN具有良好的热稳定性，不仅用作助剥离剂，还可以作为制备绿色膨胀阻燃剂体系，如三聚氰胺磷酸盐(MP) [19]、二苯氧基磷酸三聚氰胺盐[20]、三聚氰胺氰尿酸盐[21]、羟基乙叉二磷酸四三聚氰胺盐[22]等的气源使用。其中MP价格低廉，其热稳定性和吸热作用优于聚磷酸铵基的膨胀阻燃剂。MP在热分解过程中能够产生MN和多磷酸，前者热解释放NH3吸热，后者在热分解过程中产生多磷酸，使基体脱水生成均匀致密的炭层，发挥隔热、隔氧、阻燃和抑烟作用[23]。MP与类石墨氮化碳杂化时，能够提高热稳定性和阻燃效率[24]，与SiO2杂化时，可以提高疏水性和阻燃效率[19]。
因此，本文采用MN为助剥离剂，基于其与石墨烯之间的
π -π 相互作用及非共价修饰原理，通过机械球磨微粉石墨及磷酸液相反应，制备了兼具阻燃和导热性能的石墨烯纳米片杂化三聚氰胺磷酸盐(GMP)；在对其结构和热性能进行表征的基础上，探讨了GMP对EP树脂燃烧、热分解行为及导热性能的影响。1. 实验材料及方法
1.1 原材料
环氧单体(E-51)，工业纯，岳阳巴陵华兴石化有限公司；4,4-二氨基二苯甲烷(DDM)，分析纯，阿拉丁试剂上海有限公司；微粉石墨 (GRA)，ADT-005，D90：8~11 µm，石家庄科鹏阻燃材料厂；三聚氰胺(MN)，分析纯，上海安耐吉试剂有限公司；三聚氰胺磷酸盐(MP)，实验室合成，粒径小于10 μm，磷与氮含量分别为13.8%和37.5%；N,N-二甲基甲酰胺(DMF)，分析纯，阿拉丁试剂上海有限公司；磷酸，分析纯，上海迈瑞尔化学技术有限公司；无水乙醇，分析纯，北京化工厂。
1.2 GMP的制备
如图1所示，将4.5 g MN和1.5 g微粉石墨加入氧化锆研磨罐，300 r/min球磨处理16 h，得到MN剥离修饰的石墨烯纳米片(MN-GNPs)。取32.0 g MN-GNPs在95℃搅拌下，溶于320 mL的去离子水中，并缓慢滴加12.7 mL磷酸进行液相反应2 h，冷却至室温后，过滤洗涤并在75℃真空环境下干燥，得到石墨烯纳米片杂化三聚氰胺磷酸盐(GMP)。将MN-GNPs溶于DMF，7000 r/min离心15 min，取上清液在0.45 μm的聚四氟乙烯滤纸上过滤，用热水洗去三聚氰胺干燥后称重计算得GNPs含量，GNPs在GMP中的占比≥1.62wt%，MP在GMP中占比84.21wt%，其他为未完全剥离微粉石墨(含有片层较薄的石墨微片)的含量。
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图 1 石墨烯纳米片杂化三聚氰胺磷酸盐(GMP)制备路线示意图Figure 1. Schematic diagram of preparation route of graphene nanoplatelets hybrid melamine phosphate (GMP)1.3 环氧树脂(EP)复合材料的制备
按表1配方将一定量GMP、MP、GRA分别分散于无水乙醇中，超声处理2 h，将分散混合物倒入E-51中，90℃加热搅拌2 h除去乙醇，根据环氧值加入定量DDM，搅拌后抽真空，浇注于预热后的聚四氟乙烯模具中，于100℃固化2 h，150℃继续固化2 h，获得复合材料GMP/EP、MP/EP和MP-GRA/EP。纯环氧树脂在相同固化条件固化，标记为EP。
表 1 复合材料的配方及阻燃性能Table 1. Formulation and flame retardancy of compositesSample E-51/wt% DDM/wt% MP/wt% GMP/wt% GRA/wt% P/wt% LOI/% EFF UL 94 (3 mm) EP 80.0 20.0 0 0 0 0 24.5 — NR GMP20/EP 64.0 16.0 0 20.0 0 2.3 27.1 1.13 V-1 GMP25/EP 60.0 15.0 0 25.0 0 2.9 28.4 1.34 V-1 GMP30/EP 56.0 14.0 0 30.0 0 3.5 30.4 1.68 V-0 MP20/EP 64.0 16.0 20.0 0 0 2.8 26.8 0.82 V-1 MP25/EP 60.0 15.0 25.0 0 0 3.5 28.5 1.14 V-0 MP30/EP 56.0 14.0 30.0 0 0 4.2 31.0 1.55 V-0 MP-GRA20/EP 64.0 16.0 16.8 0 3.2 2.3 26.9 1.04 V-1 MP-GRA25/EP 60.0 15.0 21.1 0 3.9 2.9 28.1 1.24 V-1 MP-GRA30/EP 56.0 14.0 25.3 0 4.7 3.5 30.1 1.19 V-0 Notes: EP—Epoxy resin; E-51—Epoxy monomer; DDM—4, 4-Diaminodiphenylmethane; MP—Melamine phosphate; GMP—Graphene nanoplatelets hybrid melamine phosphate; P—Phosphorus content in composite materials; LOI—Limit oxygen index; EFF—Flame retardancy efficiency and represents the LOI increment produced by each 1wt% of phosphorus in the composites; NR—No rating. 1.4 分析与表征
采用德国布鲁克公司原子力显微镜(Dimension FastScan Bio)测定GNPs的厚度和横向尺寸；采用FEI香港有限公司扫描电子显微镜(QUNATA250)观察GMP及复合材料断面的微观形貌；采用日本电子株式会社场发射透射电镜(JEM 2100)表征GNPs形貌；采用英国雷尼绍公司拉曼光谱仪(Renishaw in Via)表征GNPs层状结构；采用美国尼高力公司傅里叶变换红外光谱仪(iS10 FT-IR Spectrometer)表征GMP的化学结构；采用日本株式会社理学X射线衍射仪(MiniFlex 600)对GMP的晶格结构进行表征；采用德国耐驰公司热重分析仪(TG 209 F1)进行GMP及复合材料的热重分析；采用美国PerkinElmer公司X射线光电子能谱仪(PHI Quantera II SXM)检测GMP表面元素的变化；采用泰思泰克(苏州)检测仪器科技有限公司氧指数仪(TTech-GBT2406-2)，依据GB/T 2406.2—2009[25]测试复合材料极限氧指数(LOI)值；采用南京江宁区分析仪器厂水平垂直燃烧测定仪(CZF-3)，依据GB/T 2408—2008[26]测试复合材料垂直燃烧等级；采用英国FTT公司FTT 0007型锥形量热仪(CONE)测试复合材料的燃烧行为，依据标准ISO 5660—1[27]，热辐照通量为50 kW/m2；使用德国耐驰公司差示扫描量热仪(DSC 204 F1)测试复合材料比热容Cp；采用德国耐驰公司激光导热仪(LFA 467)测量直径12.7 mm，厚度1 mm样品的热扩散系数α；采用排水法测得样品密度ρ；由公式λ=αρCp计算得到导热系数。
2. 结果与讨论
2.1 GMP的形貌、结构、组成及热稳定性
首先，采用TEM和AFM表征了GNPs的结构，如图2所示。图2(a)和图2(b)为GNPs的TEM图像。呈现出半透明的GNPs图像，高倍观察堆叠边缘最大厚度约为4 nm(12层)。图2(c)和图2(d)为GNPs的AFM图像及分析。显示GNPs形状不规则，其厚度约2 nm(6层)，横向尺寸在微米级。由此表明，助剥离剂MN的剥离效果良好，得到的GNPs为少层石墨烯。
其次，采用SEM表征了GMP的形貌，如图3所示。可见，与MP对比，GMP的表面形貌相对粗糙，呈不规则颗粒状。这可能由于GNPs表面吸附及MN的
π -π 相互作用，改变了晶面表面能，各向异性导致GMP晶面的生长速率不同所致[28-29]。采用Raman、XRD、FTIR、XPS及TG手段研究了GMP结构、组成及热稳定性，结果如图4所示。图4(a)的Raman曲线峰形也证实了MN助剥离得到的是少层石墨烯[14]。与微粉石墨相比，MN-GNPs的2D带下移至2687 cm−1，D峰和G峰的强度比ID/IG增至0.27，表明由
π -π 相互作用形成了缺陷较小的非共价修饰的GNPs[15,30]。![]()
图 2 石墨烯纳米片(GNPs)的TEM ((a), (b))、AFM (c) 图像和截面分析 (d)Figure 2. TEM ((a), (b)), AFM (c) images and section analysis (d) of the graphene nanosheets (GNPs)![]()
图 4 (a) 微粉石墨(GRA)和三聚氰胺(MN)-GNPs的Raman光谱；(b) GRA、MN、三聚氰胺磷酸盐(MP)、MN-GNPs和GMP的XRD图谱；(c) GRA、MP、MN-GNPs和GMP的FTIR图谱；MN-GNPs (d) 和GMP (e) 的XPS N1s图谱Figure 4. (a) Raman spectra of powder graphite (GRA) and melamine (MN)-GNPs; (b) XRD patterns of GRA, MN, melamine phosphate (MP), MN-GNPs and GMP; (c) FTIR spectra of GRA, MP, MN-GNPS and GMP; XPS N1s spectra of MN-GNPs (d) and GMP (e)ID/IG—Intensity ratio of peak D to peak G图4(b)为GRA、MN、MP、MN-GNPs和GMP的XRD图谱。可以看出，MN-GNPs和GMP在2θ=26.6°(002)形成了较石墨矮而宽的衍射峰，表明GRA被明显剥离。更重要的是GMP在2θ=17°、25.5°出现了与MP相对应的两个峰，意味着GMP的形成。FTIR和XPS结果支持了GMP的形成。由图4(c)的FTIR图谱可见，相较于MN-GNPs在3000~3500 cm−1区域的—NH2和—OH吸收峰，GMP在3392 cm−1和3131 cm−1处的吸收峰明显加宽，代表着—NH2、—NH3+及P—OH的伸缩振动；1110 cm−1和984 cm−1对应于P—OH和P—O伸缩振动[19]。同样，图4(e)为MN-GNPs和GMP的XPS N1s图谱。GMP图谱中出现了400.2 eV的—NH3+拟合峰[31]，其面积近似是—NH2的二分之一，且GMP与MP的N/P质量比基本一致(表2)，进一步证实了GMP的形成。
表 2 MN-GNPs、MP和GMP的表面元素组成Table 2. Surface elemental compositions of MN-GNPs, MP and GMPSample C/wt% N/wt% O/wt% P/wt% N/P MN-GNPs 66.1 28.7 5.2 — — MP 27.6 31.9 25.5 15.1 2.1 GMP 59.2 18.4 14.2 8.3 2.2 图5为氮气气氛下GRA、MP和GMP的TGA和DTG曲线。可以看出，GRA表现出较高的热稳定性，GNPs的存在导致GMP的初始热分解温度(292.6℃，5wt%失重)较MP(263.3℃)提高了29.3℃，与EP的初始热分解温度(368.1℃)更接近，EP的初始热分解温度的测试数据见表3。且最大热失重速率降低、700℃下残渣量显著提高。GMP初始热分解温度与基材匹配性更好及残渣量的提高是获得良好凝聚相阻燃效果的重要因素。
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图 5 氮气气氛下GRA、MP和GMP的TGA (a) 和DTG (b) 曲线Figure 5. TGA (a) and DTG (b) curves of GRA, MP and GMP under N2 atmosphere表 4 EP、GMP/EP、MP/EP复合材料锥形量热仪测试数据Table 4. Combustion parameters of EP, GMP/EP, MP/EP composites from cone testSample TTI/s PHRR/(kW·m−2) THR/(MJ·m−2) PSPR/(m2·s−1) TSP/(m2·kg−1) CR/% EP 40 954.8 90.0 0.454 41.9 5.0 GMP20/EP 37 339.5 70.2 0.144 26.1 23.6 GMP30/EP 42 297.4 62.7 0.118 19.5 31.3 MP20/EP 37 285.3 77.1 0.127 22.9 24.8 MP30/EP 37 247.7 68.6 0.116 18.7 29.6 Notes: TTI—Time to ignition; PHRR—Peak heat release rate; THR—Total heat release; PSPR—Peak smoke produce rate; TSP—Total smoke production; CR—Char residues. 2.2 复合材料的阻燃性能
表1给出了复合材料的氧指数(LOI)和UL 94垂直燃烧测试结果。当GMP的用量增加至30wt%， GMP30/EP复合材料的LOI上升至难燃级(大于30%)，UL 94达到V-0级。为了进一步分析材料阻燃性能，对GMP/EP、MP/EP和MP-GRA/EP复合材料的阻燃效率(EFF)[32]进行了比较，GMP/EP的EFF最高。尽管MP添加量达25 wt%时，复合材料就可以通过V-0级，但MP/EP的EFF低于GMP/EP和MP-GRA/EP。由于GMP中MP的含量为84.21wt%，GMP/EP和MP-GRA/EP复合材料中的磷含量低于MP/EP，因此GMP/EP和MP-GRA/EP中1wt%磷产生的LOI增值更高。上述结果不仅与GMP热解吸热及热解产物多磷酸对基材的脱水交联成炭阻燃作用有关，而且与石墨微片和GNPs的阻隔机制有关。
锥形量热仪测试(CONE)是模拟真实火灾条件下材料燃烧行为的重要研究手段。图6和表4为EP和复合材料CONE燃烧测试结果，包括点燃时间(TTI)、热释放速率(HRR)及峰值HRR(PHRR)、烟释放速率(SPR)及峰值SPR(PSPR)、总热释放速率(THR)、总烟释放量(TSP)、平均有效燃烧热(Av-EHC)及残炭率(CR)。从表4可以看出，与MP对比，GMP 使TTI略有延长，与GNPs的阻隔作用有关。虽然在30wt%添加量下，GMP30/EP的PHRR、PSPR及TSP略高于MP30/EP，但与EP比较，降低幅度高达69%、74%和53%，且GMP30/EP的THR(62.7 MJ·m−2)最低。
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图 6 EP、GMP/EP、MP/EP复合材料的热释放速率(HRR) (a)、总热释放速率(THR) (b)、烟释放速率(SPR) (c) 和总烟释放量(TSP) (d) 曲线Figure 6. Heat release rate (HRR) (a), total heat release rate (THR) (b), smoke release rate (SPR) (c) and total smoke release (TSP) (d) curves of EP, GMP/EP, MP/EP composites表 3 复合材料在N2气氛下的TG和DTG数据Table 3. TG and DTG data of composites materials under N2 atmosphereSample T5%/℃ ΔT5%/℃ Tmax/℃ CR700℃/% ΔCR700℃/% Exp. Cal. Exp. Cal. EP 368.1 — — 382.9 20.1 — — GMP 292.6 — — 396.4 42.0 — — MP 263.3 — — 391.2 28.1 — — GMP20/EP 328.5 353.0 −24.5 364.0 29.7 24.2 5.5 GMP30/EP 337.8 345.4 −8.0 363.3 38.2 26.5 11.7 MP20/EP 332.8 347.1 −14.3 363.8 30.7 21.5 9.2 MP30/EP 329.5 336.7 −7.2 363.3 33.5 22.3 11.2 Notes: Exp.—Test results; Cal.—Calculated results; T5%—Temperature with mass loss of 5wt%; Tmax—Maximum decomposition temperature; CR700℃—Char residues at 700℃; ΔT5%=T5%Exp.— T5%Cal.; ΔCR700℃=CR700℃Exp.— CR700℃Cal. 另外，CR随阻燃剂含量的增大而增加，体现了稳定炭层的形成与MP促进成炭和石墨微片及GNPs阻隔作用的结合。CR的增加能够将更多的热分解产物保留在凝聚相，延缓材料燃烧过程热和烟的释放。正如图7中所示的CONE测试后残炭数码照片及相应的SEM图像，相对EP残炭，GMP20/EP的残炭表面结构完整，裂纹很少，GMP表现出了膨胀成炭效果。内嵌SEM图像显示表面致密均匀，内部以石墨微片或GNPs为骨架形成了多重网络，具有阻碍热量和物质交换的凝聚相阻燃作用，显著抑制了热和烟的释放。
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图 7 EP (a) 和GMP20/EP (b) 残炭的数码照片和插入的SEM图像Figure 7. Digital photos and inserted SEM images of EP (a) and GMP20/EP (b) char residues2.3 复合材料的热分解行为
热分解行为的研究有助于理解GMP对复合材料燃烧性能的影响规律。从图8和表3给出的TG、DTG曲线及相关数据可见，复合材料的初始分解温度(T5%，失重5wt%对应的温度)、最大热分解温度(Tmax)低于EP基材，700℃下的残炭率显著增加。GMP30/EP与MP30/EP复合材料CR增加的幅度相对较大，与上述阻燃性能提高的规律一致，反映了阻燃剂的凝聚相作用机制。值得注意的是复合材料的T5%，通过计算值T5%Cal.的分析可见，对于实验值与计算值的差值ΔT5%，GMP/EP较MP/EP降低得更多，说明除了受阻燃剂T5%偏低的影响之外，GMP促进基材热降解的作用更强。源于GNPs的催化热降解[10]与MP促进基材脱水交联作用的结合。
2.4 复合材料的导热性能及机制
图9为EP复合材料导热性能与阻燃剂添加量的关系。可见，随阻燃剂添加量的增加GMP/EP的导热系数上升最显著。30 wt%添加量下, GMP30/EP的导热系数高达2.10 W·m−1·K−1，相对于基材EP提高了708%，相对于MP30/EP和MP-GRA30/EP分别提高了239%和275%，且优于BN[33-34]、AlN[35]、Al2O3[36-37]、石墨[38]等传统导热填料(图10)，反映了石墨烯纳米片杂化阻燃剂GMP的多功能性和先进性。另外，值得注意的是GMP/EP曲线约在20wt%添加量附近呈现出导热系数变化的拐点，反映出纳米填料的逾渗现象。
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图 8 氮气气氛下EP、GMP/EP、MP/EP复合材料的TG (a) 和DTG (b) 曲线Figure 8. TG (a) and DTG (b) curves of EP, GMP/EP, MP/EP composites under N2 atmosphereGMP赋予复合材料导热性的原因主要有两方面，一是GMP含有MN非共价修饰剥离的高导热GNPs；其二是磷酸盐类化合物对环氧树脂具有良好的相容性，使GMP在基材有良好的分散性。由表5可见，复合材料的导热系数是热扩散系数、比热容、密度三者的乘积， GMP30/EP复合材料的热扩散系数最大，源于GNPs高导热的贡献。从图11复合材料的断面形貌可见，相对于图11(g)EP光滑的断面而言，复合材料的断面都显得粗糙。而图11(b)GMP30/EP中的阻燃剂与树脂界面相对模糊，说明GMP与树脂具有良好的相容性，导致GMP在基材中有良好的分散性，也使得材料具有更高的比热容Cp。相反，图11(f)的MP-GRA30/EP界面最清晰，说明MP与GRA共混的阻燃剂与树脂的相容性最差，分散性差的阻燃剂不能有效搭接形成导热网络，因此MP-GRA/EP表现出相对低的导热性能。为此，提出图11(h)~11(k)所示的导热机制，良好分散的填料使高导热石墨烯纳米片与石墨微片搭接形成热传导通道，显著降低了界面热阻，于是GMP/EP复合材料表现出相对最好的导热性能。
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图 9 EP复合材料导热系数与阻燃剂添加量的关系Figure 9. Relationship between thermal conductivity and flame retardants contents of EP composites![]()
表 5 复合材料的热扩散系数α、比热容Cp、密度ρ及导热系数λTable 5. Thermal diffusivity α, specific heat capacity Cp, density ρ and thermal conductivity λ of compositesSample GNPs/wt% GRA/wt% α/(mm2·s−1) Cp/( J·g−1·K−1) ρ/(g·cm−3) λ/(W·m−1·K−1) EP 0 0 0.163 1.428 1.103 0.26 GMP30/EP ≥0.5 ≤4.2 0.588 2.537 1.409 2.10 MP30/EP 0 0 0.197 2.483 1.274 0.62 MP-GRA30/EP 0 4.7 0.253 1.695 1.305 0.56 ![]()
图 11 GMP30/EP ((a), (b), (h))、MP30/EP ((c), (d), (i))、MP-GRA30/EP ((e), (f), (j)) 和EP ((g), (k)) 复合材料断裂表面的SEM图像及导热机制Figure 11. SEM images of fractured surfaces and heat conductive mechanism of GMP30/EP ((a), (b), (h)), MP30/EP ((c), (d), (i)), MP-GRA30/EP ((e), (f), (j)) and EP ((g), (k)) composites3. 结 论
(1) 基于三聚氰胺和石墨烯之间的
π -π 相互作用，采用三聚氰胺为助剥离剂机械球磨的微粉石墨与磷酸液相反应，成功制备了石墨烯纳米片杂化三聚氰胺磷酸盐(GMP)。GMP中石墨烯纳米片的厚度约2 nm(6层)，横向尺寸在微米级；GMP较三聚氰胺磷酸盐(MP) 初始分解温度提升了29.3℃，有更好的热稳定性。(2) 加入30wt%的GMP，环氧树脂(EP)复合材料的氧指数达到了30.4%，UL 94垂直燃烧为V-0级，峰值热释放和烟释放速率较EP分别降低了69%、74.0%。EP复合材料阻燃性能的提高与石墨微片和石墨烯纳米片良好分散、阻隔作用及三聚氰胺磷酸盐成炭作用结合有关。
(3) GMP/EP复合材料的导热系数随着GMP添加量增加而提高。当GMP含量为30 wt%时，GMP/EP复合材料的导热系数达到2.10 W·m−1·K−1，相对于EP提升了708%。
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图 1 玻璃纤维/甲基丙烯酸酯基原位固化管道(CIPP)内衬的固化和切割好的试样
Figure 1. Curing of glass fiber reinforced methacrylate-based cured-in-place-pipe (CIPP) linings and cut specimens
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图 2 玻璃纤维/甲基丙烯酸酯基CIPP内衬加速老化后的吸水行为：(a) 增重；(b) 扩散系数和饱和吸水率
Figure 2. Water absorption behavior of glass fiber reinforced methacrylate-based CIPP lining after accelerated aging: (a) Mass gain; (b) Diffusion coefficient and saturated water content
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图 3 玻璃纤维/甲基丙烯酸酯基CIPP内衬加速老化后的弯曲强度
Figure 3. Flexural strength of glass fiber reinforced methacrylate-based CIPP lining after accelerated aging
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图 4 玻璃纤维/甲基丙烯酸酯基CIPP内衬在3种条件下加速老化后的弯曲应力-应变曲线：(a) 0.5%硫酸；(b) 模拟海水；(c) 纯水
Figure 4. Flexural stress-strain curves of glass fiber reinforced methacrylate-based CIPP lining after accelerated aging under three conditions: (a) 0.5% sulfuric acid; (b) Simulated seawater; (c) Pure water
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图 5 未老化和3种条件下加速老化
1440 h后的玻璃纤维/甲基丙烯酸酯基CIPP内衬表面和弯曲断面微观形貌Figure 5. Micromorphology of the surface and curved cross section of glass fiber reinforced methacrylate-based CIPP lining without aging and after accelerated aging
1440 h under three conditions![]()
图 6 (a)硫酸和海水腐蚀玻璃纤维/甲基丙烯酸酯基CIPP内衬；(b)树脂/纤维界面劣化；(c)弯曲断裂模式
Figure 6. (a) Sulfuric acid and seawater corrode glass fiber reinforced methacrylate-based CIPP lining; (b) Degradation of resin fiber interface; (c) Bending fracture modes
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图 7 未老化和3种条件下加速老化
1440 h后的玻璃纤维/甲基丙烯酸酯基CIPP内衬表面的FTIR图谱Figure 7. FTIR spectra of glass fiber reinforced methacrylate-based CIPP lining without aging and after accelerated aging
1440 h under three conditions![]()
图 9 (a)玻璃纤维/甲基丙烯酸酯基CIPP内衬加速老化
1440 h后的颜色变化；(b)盐壳Figure 9. (a) Color change of glass fiber reinforced methacrylate-based CIPP lining after accelerated aging
1440 h; (b) Salt crust![]()
图 10 玻璃纤维/甲基丙烯酸酯基CIPP内衬加速老化后的表面接触角
Figure 10. Surface contact angle of glass fiber reinforced methacrylate-based CIPP lining after accelerated aging
表 1 模拟海水成分
Table 1 Simulated seawater composition
Compound Concentration/(g·L−1) NaCl 24.53 MgCl2 5.20 Na2SO4 4.09 CaCl2 1.16 KCl 0.695 NaHCO3 0.201 KBr 0.101 H3BO3 0.027 SrCl2 0.025 NaF 0.003 
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表 2 玻璃纤维/甲基丙烯酸酯基CIPP内衬加速老化
1440 h前后的羰基指数和羟基指数Table 2 Carbonyl index and hydroxyl index of glass fiber reinforced methacrylate-based CIPP lining before and after accelerated aging 1 440 h
Condition Carbonyl index Hydroxyl index Before aging Aging 1440 hBefore aging Aging 1440 h0.5% sulfuric acid 0.560±0.025 0.807±0.026 0±0.01 0.038±0.028 Simulated seawater 0.591±0.019 0.056±0.023 Pure water 0.824±0.021 0.039±0.035
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[1] DONALDSON B M. Environmental implications of cured-in-place pipe rehabilitation technology[J]. Transportation Research Record, 2009, 2123(1): 172-179. DOI: 10.3141/2123-19
[2] ZHU H, WANG T, WANG Y, et al. Trenchless rehabilitation for concrete pipelines of water infrastructure: A review from the structural perspective[J]. Cement and Concrete Composites, 2021, 123: 104193. DOI: 10.1016/j.cemconcomp.2021.104193
[3] LI S, GUO S C, YAO Y M, et al. The effects of aging in seawater and SWSSC and strain rate on the tensile performance of GFRP/BFRP composites: A critical review[J]. Construction and Building Materials, 2021, 282: 122534.
[4] NURUDDIN M, DECOCKER K, SENDESI S M T, et al. Influence of aggressive environmental aging on mechanical and thermo-mechanical properties of ultra violet (UV) cured in place pipe liners[J]. Journal of Composite Materials, 2020, 54(23): 3365-3379. DOI: 10.1177/0021998320913988
[5] RA K, SENDESI S M T, NURUDDIN M, et al. Considerations for emission monitoring and liner analysis of thermally manufactured sewer cured-in-place-pipes (CIPP)[J]. Journal of Hazardous Materials, 2019, 371: 540-549. DOI: 10.1016/j.jhazmat.2019.02.097
[6] GRAS-TRAVESSET F, ANDREU-TORRAS A, PÉREZ M A. A novel test procedure for evaluating the performance of composite cured-in-place-pipe liners in water pressure pipe rehabilitation[J]. Case Studies in Construction Materials, 2023, 19: e02381. DOI: 10.1016/j.cscm.2023.e02381
[7] VAHIDI E, JIN E, DAS M, et al. Environmental life cycle analysis of pipe materials for sewer systems[J]. Sustainable Cities and Society, 2016, 27: 167-174. DOI: 10.1016/j.scs.2016.06.028
[8] ALLOUCHE E, ALAM S, SIMICEVIC J, et al. A pilot study for retrospective evaluation of cured-in-place pipe (CIPP) rehabilitation of municipal gravity sewers[J]. Tunnelling and Underground Space Technology, 2014, 39: 82-93. DOI: 10.1016/j.tust.2012.02.002
[9] OKABE S, ODAGIRI M, ITO T, et al. Succession of sulfur-oxidizing bacteria in the microbial community on corroding concrete in sewer systems[J]. Applied and Environmental Microbiology, 2007, 73(3): 971-980. DOI: 10.1128/AEM.02054-06
[10] VALIX M, SHANMUGARAJAH K. Biogenic acids produced on epoxy linings installed in sewer crown and tidal zones[J]. Water Research, 2015, 80: 217-226. DOI: 10.1016/j.watres.2015.05.027
[11] 魏建辉, 刘明, 高进城, 等. 吸湿老化后碳纤维增强乙烯基脂树脂复合材料高低温力学性能[J]. 复合材料学报, 2023, 40(6): 3279-3290. WEI Jianhui, LIU Ming, GAO Jincheng, et al. Mechanical properties at elevated and cryogenic temperatures of carbon fiber reinforced vinylester resin composites after hygroscopic aging[J]. Acta Materiae Compositae Sinica, 2023, 40(6): 3279-3290(in Chinese).
[12] NODEHI M. Epoxy, polyester and vinyl ester based polymer concrete: A review[J]. Innovative Infrastructure Solutions, 2021, 7(1): 64.
[13] VIEIRA P S, DA SILVA G A, LOPES B J, et al. Hygrothermal aging of steel/frp pipe repair systems: A literature review[J]. International Journal of Pressure Vessels and Piping, 2023, 201: 104881. DOI: 10.1016/j.ijpvp.2022.104881
[14] 高坤, 史汉桥, 孙宝岗, 等. 湿热老化对玻璃纤维/环氧树脂复合材料性能的影响[J]. 复合材料学报, 2016, 33(6): 1147-1152. GAO Kun, SHI Hanqiao, SUN Baogang, et al. Effects of hydro-thermal aging on properties of glass fiber/epoxy composites[J]. Acta Materiae Compositae Sinica, 2016, 33(6): 1147-1152(in Chinese).
[15] AITHAL S, HOSSAGADDE P N, KINI M V, et al. Durability study of quasi-isotropic carbon/epoxy composites under various environmental conditions[J]. Iranian Polymer Journal, 2023, 32(7): 873-885. DOI: 10.1007/s13726-023-01172-x
[16] VISCO A M, BRANCATO V, CAMPO N. Degradation effects in polyester and vinyl ester resins induced by accelerated aging in seawater[J]. Journal of Composite Materials, 2011, 46(17): 2025-2040.
[17] HE W, LI X, LI P, et al. Experimental investigation on hygroscopic aging of glass fiber reinforced vinylester resin composites[J]. Polymers, 2022, 14(18): 3828. DOI: 10.3390/polym14183828
[18] 曹银龙, 于桢琪, 冯鹏, 等. 纤维增强环氧/乙烯基树脂复合材料性能优化与劣化机制研究进展[J]. 复合材料学报, 2024, 41(3): 1179-1191. CAO Yinlong, YU Zhenqi, FENG Peng, et al. Performance optimization and deterioration mechanism of fiber reinforced epoxy/vinyl resin composite materials: A review[J]. Acta Materiae Compositae Sinica, 2024, 41(3): 1179-1191(in Chinese).
[19] JOSÉ-TRUJILLO E, RUBIO-GONZÁLEZ C, RODRÍGUEZ-GONZÁLEZ J. Seawater ageing effect on the mechanical properties of composites with different fiber and matrix types[J]. Journal of Composite Materials, 2019, 53(23): 3229-3241. DOI: 10.1177/0021998318811514
[20] KANERVA M, JOKINEN J, SARLIN E, et al. Lower stiffness of GFRP after sulfuric acid-solution aging is due to degradation of fibre-matrix interfaces?[J]. Composite Structures, 2019, 212: 524-534. DOI: 10.1016/j.compstruct.2019.01.006
[21] LI H, GU P, WATSON J, et al. Acid corrosion resistance and mechanism of E-glass fibers: Boron factor[J]. Journal of Materials Science, 2013, 48(8): 3075-3087. DOI: 10.1007/s10853-012-7082-y
[22] 韦嘉盛, 戴磊, 贺瓶. 基于纤维素及其衍生物的凝胶材料设计[J]. 复合材料学报, 2022, 39(7): 3084-3103. WEI Jiasheng, DAI Lei, HE Ping. Design of gel materials with cellulose and its derivatives[J]. Acta Materiae Compositae Sinica, 2022, 39(7): 3084-3103(in Chinese).
[23] DEVINE M, BAJPAI A, OBANDE W, et al. Seawater ageing of thermoplastic acrylic hybrid matrix composites for marine applications[J]. Composites Part B: Engineering, 2023, 263: 110879. DOI: 10.1016/j.compositesb.2023.110879
[24] DAVIES P, LE GAC P Y, LE GALL M. Influence of sea water aging on the mechanical behaviour of acrylic matrix composites[J]. Applied Composite Materials, 2017, 24(1): 97-111. DOI: 10.1007/s10443-016-9516-1
[25] DUO Y, LIU X, LIU Y, et al. Environmental impact on the durability of FRP reinforcing bars[J]. Journal of Building Engineering, 2021, 43: 102909. DOI: 10.1016/j.jobe.2021.102909
[26] VISCO A, BRANCATO V, CAMPO N. Degradation effects in polyester and vinyl ester resins induced by accelerated aging in seawater[J]. Journal of Composite Materials, 2012, 46(17): 2025-2040. DOI: 10.1177/0021998311428533
[27] American Society for Testing and Materials International. Standard practice for preparation of substitute ocean water: ASTM D1141—98(2021)[S]. West Conshohocken: ASTM International, 2021.
[28] HONG B, XIAN G, LI H. Comparative study of the durability behaviors of epoxy-and polyurethane-based CFRP plates subjected to the combined effects of sustained bending and water/seawater immersion[J]. Polymers, 2017, 9(11): 603. DOI: 10.3390/polym9110603
[29] GRAMMATIKOS S A, EVERNDEN M, MITCHELS J, et al. On the response to hygrothermal aging of pultruded FRPs used in the civil engineering sector[J]. Materials & Design, 2016, 96: 283-295.
[30] 吴瑞, 李岩, 于涛. 不同种类纤维增强复合材料湿热老化性能对比[J]. 复合材料学报, 2022, 39(9): 4406-4419. WU Rui, LI Yan, YU Tao. Comparative study on the hygrothermal durability of different fiber reinforced composites[J]. Acta Materiae Compositae Sinica, 2022, 39(9): 4406-4419(in Chinese).
[31] American Society for Testing and Materials International. Standard test method for flexural properties of polymer matrix composite materials: ASTM D7264/D7264M—21[S]. West Conshohocken: ASTM International, 2021.
[32] AWAD S A, FELLOWS C M, SAEED MAHINI S. A comparative study of accelerated weathering of epoxy resins based on DGEBA and HDGEBA[J]. Journal of Polymer Research, 2018, 25: 1-8. DOI: 10.1007/s10965-017-1408-z
[33] ASLAN A, SALUR E, DÜZCÜKOĞLU H, et al. The effects of harsh aging environments on the properties of neat and MWCNT reinforced epoxy resins[J]. Construction and Building Materials, 2021, 272: 121929. DOI: 10.1016/j.conbuildmat.2020.121929
[34] FANG Y, WANG K, HUI D, et al. Monitoring of seawater immersion degradation in glass fibre reinforced polymer composites using quantum dots[J]. Composites Part B: Engineering, 2017, 112: 93-102. DOI: 10.1016/j.compositesb.2016.12.043
[35] LIU T, LIU X, FENG P. A comprehensive review on mechanical properties of pultruded FRP composites subjected to long-term environmental effects[J]. Composites Part B: Engineering, 2020, 191: 107958. DOI: 10.1016/j.compositesb.2020.107958
[36] BEURA S, CHAKRAVERTY A, PATI S, et al. Effect of salinity and strain rate on sea water aged GFRP composite for marine applications[J]. Materials Today Communications, 2023, 34: 105056. DOI: 10.1016/j.mtcomm.2022.105056
[37] FENG Z, SONG G L, WANG Z M, et al. Salt crystallization-assisted degradation of epoxy resin surface in simulated marine environments[J]. Progress in Organic Coatings, 2020, 149: 105932. DOI: 10.1016/j.porgcoat.2020.105932
[38] MA Y, YANG Y, SUGAHARA T, et al. A study on the failure behavior and mechanical properties of unidirectional fiber reinforced thermosetting and thermoplastic composites[J]. Composites Part B: Engineering, 2016, 99: 162-172. DOI: 10.1016/j.compositesb.2016.06.005
[39] WU C, MENG B C, TAM L H, et al. Yellowing mechanisms of epoxy and vinyl ester resins under thermal, UV and natural aging conditions and protection methods[J]. Polymer Testing, 2022, 114: 107708. DOI: 10.1016/j.polymertesting.2022.107708
[40] SMITH B. Infrared spectroscopy of polymers, VIII: Polyesters and the rule of three[J]. Spectroscopy, 2022, 37(10): 25-28.
[41] ARRIETA J S, RICHAUD E, FAYOLLE B, et al. Thermal oxidation of vinyl ester and unsaturated polyester resins[J]. Polymer Degradation and Stability, 2016, 129: 142-155. DOI: 10.1016/j.polymdegradstab.2016.04.003
[42] BAKLAN D, BILOUSOVA A, MYRONYUK O. UV aging of styrene-acrylic polymer SiO2 and TiO2 composites[J]. Materials Today Communications, 2024, 38: 107990. DOI: 10.1016/j.mtcomm.2023.107990
[43] YUAN Y, HAYS M P, HARDWIDGE P R, et al. Surface characteristics influencing bacterial adhesion to polymeric substrates[J]. RSC Advances, 2017, 7(23): 14254-14261. DOI: 10.1039/C7RA01571B
[44] WANG J, WU Y, CAO Y, et al. Influence of surface roughness on contact angle hysteresis and spreading work[J]. Colloid and Polymer Science, 2020, 298(8): 1107-1112. DOI: 10.1007/s00396-020-04680-x
[45] SANCHIS M, BLANES V, BLANES M, et al. Surface modification of low density polyethylene (LDPE) film by low pressure O2 plasma treatment[J]. European Polymer Journal, 2006, 42(7): 1558-1568. DOI: 10.1016/j.eurpolymj.2006.02.001
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其他相关附件
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原位固化管道(Cured-in-place-pipe, CIPP)修复是目前市政排水管道非开挖修复常用的技术方法。该方法通过将热固性树脂和玻璃纤维组成的复合材料拉入到劣化管道内，固化后在管道内壁形成一层保护性管道内衬，保护排水管道免受生物硫酸的腐蚀，近年来也越来越多的应用于市政排海管道，抵抗海水的腐蚀，而硫酸和海水劣化玻璃纤维/甲基丙烯酸酯基CIPP内衬的机制尚不明确。
本文设计了0.5％硫酸、模拟海水和纯水(对照)三种老化条件，来模拟CIPP内衬服役环境，并通过高温(80℃)加速老化。结果显示：三种条件下加速老化1440 h后CIPP内衬弯曲强度显著下降，而弯曲模量没有明显变化；酯键水解出的羟基被氧化为羰基，导致了树脂老化后颜色发黄；硫酸通过腐蚀表面玻璃纤维促进了水分的扩散，但是H+离子没有大量沿界面向深处扩散，劣化内部玻璃纤维，硫酸老化也降低了表面润湿性，可能更有利于硫细菌黏附；海水在树脂表面的结晶阻碍了水分扩散，却严重破坏了树脂表面。分析了界面的劣化机制，提出了延缓CIPP内衬老化的建议：重点抑制水分向树脂基体的扩散、抑制水分沿界面的扩散，也应该改善树脂表面性能。
(a) 硫酸和海水腐蚀玻璃纤维/甲基丙烯酸酯基CIPP内衬；(b)树脂/纤维界面劣化；(c)弯曲断裂模式
树脂基体化学结构变化
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