秸秆地质聚合物复合材料环境稳定性研究

在地质聚合物合成过程中掺入秸秆,合成一种具有良好保温性能的材料——秸秆地质聚合物复合材料.环境稳定性是材料的重要指标,考察了该复合材料耐酸雨淋溶和抗氧化硫硫杆菌侵蚀性能.实验结果表明:秸秆地质聚合物复合材料在pH值为3以上的酸雨淋溶下,抗压强度维持在36MPa左右,扫描电镜显示其内部层状结构完好,耐酸雨淋溶性能良好.将复合材料浸泡在氧化硫硫杆菌的菌液中,21d抗压强度为26.30 MPa,28d抗压强度仍有18.40 MPa,傅里叶红外光谱和扫描电镜结果显示氧化硫硫杆菌虽然会对秸秆地质聚合物抗压强度产生一定影响,但其无定型三维网状硅铝酸盐结构依然存在.     

钛酸钾晶须改性偏高岭土基多孔地质聚合物的制备与性能

为提高多孔地质聚合物的力学强度和隔热性能,分别以双氧水（H2O2）和十二烷基硫酸钠（SDS）为发泡剂和稳泡剂,采用化学发泡法制备了由钛酸钾晶须改性的偏高岭土基多孔地质聚合物材料,对其进行了微观结构表征及性能测试。结果表明,当发泡剂和稳泡剂质量分数分别为2.0%和1.5%时,孔结构分布均匀,总孔隙率最高可达51.6%,平均孔径为0.87 mm,其抗压强度为3.63 MPa;随着钛酸钾晶须质量分数从0.0%增至10.0%时,其最高抗压强度可达4.11 MPa。在钛酸钾晶须质量分数为20%时,其最低导热系数可达0.048 W/（m?K）,相比于空白样,抗压强度提高了13.22%,导热系数降低了80.80%。钛酸钾晶须的引入可以明显提高多孔地质聚合物的抗压强度和隔热性能。     

碱激发赤泥-矿渣地质聚合物制备及力学性能研究

采用氢氧化钠和水玻璃复合碱激发剂对赤泥-矿渣进行活性激发制备地质聚合物,研究了矿渣的掺量、激发剂模数及固含量对赤泥-矿渣地质聚合物力学性能的影响,并对地质聚合物的产物及微观结构进行了分析。结果表明:当矿渣掺量低于50%时,随着矿渣掺量的增加地质聚合物的抗压强度逐渐增大。但当矿渣掺量过高时,地质聚合物的抗压强度反而会下降,矿渣掺量为70%的地质聚合物28d抗压强度与矿渣掺量为50%时相比下降了6.75%。赤泥-矿渣地质聚合物在水化反应过程中逐渐生成新的蜂窝状和片层状的无定形态凝胶相结构,且通过能谱分析得出该凝胶相结构为N-A-S-H凝胶和C-A-S-H凝胶组成的混合体。     

粉煤灰-矿渣复合基地质聚合物力学性能的影响因素

地质聚合物作为一种新型的绿色胶凝材料,与硅酸盐水泥相比,地质聚合物具有环境友好、耐高温、耐久性好等优点.本实验采用工业固体废物粉煤灰和矿渣,配以石英砂和碱硅酸盐激发剂,制备得到地质聚合物材料.以制品抗压强度为指标,研究了粉煤灰与矿渣复合比、碱硅酸盐激发剂的模数与固含量、以及液胶比对地质聚合物性能的影响规律.结果表明:随着粉煤灰占总胶凝材料比例的增加,体系中CaO的含量降低,地质聚合物的抗压强度逐渐降低;当碱硅酸盐激发剂固含量为32%时,地聚物抗压强度随其模数的增大表现为先增大后减小,当模数为1.2时,试样7d抗压强度达到94.9 MPa;对于液胶比,随液胶比的增大,地聚物的抗压强度先增大后减小,液胶比为0.48时,抗压强度最大.     

矿渣基地质聚合物干粉材料的性能与反应机理

以矿渣和水玻璃粉体为原料制备地质聚合物干粉材料,研究了水灰比对地质聚合物凝结时间和强度的影响,通过XRD、SEM和FTIR等分析技术系统研究了水玻璃粉体制备矿渣基地质聚合物的物相组成、微观结构和分子结构,分析了水玻璃粉体激发矿渣的反应机理。结果显示,水灰比从0.30增加到0.38,干粉材料的初凝时间从10min增加到22min,终凝时间从13min增加到26min,抗压强度从82.9MPa减少到63.4MPa。微观分析表明水玻璃粉体与矿渣的反应以地质聚合反应为主,矿渣基地质聚合物为无定形的网络结构。     

超轻质地质聚合物材料的制备及性能研究

以粉煤灰、偏高岭土为主要原料,通过碱激发剂和发泡剂共同作用制备超轻质地质聚合物,研究不同发泡方式、稳泡剂种类及掺量、养护温度和养护时间对超轻质地质聚合物性能的影响.研究结果表明:相较于物理发泡法,采用化学发泡法制备的超轻质地质聚合物,其泡孔分布更为均匀、大小规则且结构致密;以十二烷基苯磺酸钠稳泡剂制备的轻质地质聚合物材料,其泡孔封闭性较差,内部存在孔隙较多,而使用硬脂酸钙稳泡剂制备的材料其孔结构则多为封闭孔,其泡孔分布也更为均匀,孔径尺寸多在0.3～1.2 mm之间;超轻质地质聚合物的最佳制备工艺为:H202发泡剂和CS稳泡剂掺量为5.5wt％、养护温度和时间分别为60℃、24 h,此时超轻质地质聚合物导热系数为0.055 W/(m·K),干密度为190 kg/cm3,抗压强度为0.95 MPa.     

几种填料对偏高岭土-粉煤灰基地质聚合物的增强改性

为提高地质聚合物（GP）的力学强度,制备了含钛酸钾晶须、磷酸钙（β-TCP）、羟基磷灰石（HAP）和碳纳米管（CNTs）增强填料的偏高岭土-粉煤灰基GP复合材料,对其进行了抗压强度测试,并且采用了扫描电子显微镜（SEM）、X-射线衍射仪、傅里叶变换红外光谱仪以及热重分析仪分别表征了其微观形貌、结晶形态、化学组成以及耐热性能。研究结果表明,由钛酸钾晶须、β-TCP、HAP和CNTs增强的GP的最大抗压强度分别可达71.97,65.10,70.98,67.02 MPa。比纯GP的最大抗压强度（56.91 MPa）分别提高了26.46%,14.39%,24.72%,17.76%。SEM表征显示,加入增强填料后,GP试样断面裂缝大大减少,结构也比纯GP更密实,这有利于提高GP的抗压强度。此外,2%质量分数的钛酸钾晶须能使GP的热失重率降低22.7%,有效地提高了GP的耐热性能。     

偏高岭土基地质聚合物合成条件的试验研究

研究了由不同产地的高岭土经不同煅烧条件所得的偏高岭土、水玻璃类型和模数、碱含量及养护条件等对地质聚合物合成的影响规律．结果表明：某种苏州高岭土经800℃煅烧6h活性最好,即在碱液中硅铝溶出率最大;当水玻璃模数为1．4,碱含量为10％时,制得的地质聚合物在20℃（相对湿度大于90％）的条件下养护28d,其抗压强度达到82．5MPa．合成地质聚合物中的偏高岭土的活性、水玻璃模数、碱含量和养护条件达到最佳匹配条件时,其抗压强度最大．     

粉煤灰聚合物的制备与性能分析

以粉煤灰为主要原料,用正交试验法探讨砂子、水泥、白灰掺量对粉煤灰地质聚合物强度的影响。采用适当的配比,其28d后抗折强度达到5.28MPa,抗压强度达到27.49MPa,可以应用于建筑的承重墙及其它承重建筑。     

聚合物改性黏结砂浆的性能研究

根据加气混凝土用黏结砂浆不同的界面破坏形式,综合评价加气混凝土用黏结砂浆的黏接性能,并通过正交设计试验对黏结砂浆进行聚合物改性研究,探讨了羟丙基甲基纤维素醚(HPMC)、聚乙烯醇(PVA)和α型高强石膏对砂浆各项性能的影响.试验表明,聚合物改性黏结砂浆的最佳配比为:水胶比为0.525,α型半水石膏的掺量为50%,HPMC的掺量为0.50%,PVA的掺量为0.5%.最终产物的抗折强度为3.51 MPa,抗压强度为9.00 MPa,折压比为0.39,拉伸黏结强度为0.315 MPa,基材破坏率为100%.     

Preparation and properties of geopolymer-lightweight aggregate refractory concrete

Geopolymer-lightweight aggregate refractory concrete (GLARC) was prepared with geopolymer and lightweight aggregate. The mechanical property and heat-resistance (950 °C) of GLARC were investigated. The effects of size of aggregate and mass ratio of geopolymer to aggregate on mechanical and thermal properties were also studied. The results show that the highest compressive strength of the heated refractory concrete is 43.3 MPa, and the strength loss is only 42%. The mechanical property and heat-resistance are influenced by the thickness of geopolymer covered with aggregate, which can be expressed as the quantity of geopolymer on per surface area of aggregate. In order to show the relationship between the thickness of geopolymer covered with aggregate and the thermal property of concrete, equal thickness model is presented, which provides a reference for the mix design of GLARC. For the haydite sand with size of 1.18–4.75 mm, the best amount of geopolymer per surface area of aggregate should be in the range of 0.300–0.500 mg/mm².     

Strength and Microstructural Analysis of Geopolymer Prepared with Recycled Geopolymer Powder

The strength and microstructural analysis of recycled geopolymer are presented in this paper.Five kinds of geopolymers containing 0%,20%,50%,80% and 100 % of recycled geopolymer powder were prepared using metakaolin as the source material.The alkali activator solution was a mixture of sodium silicate (Na_2SiO_3) and 12 M sodium hydroxide (NaOH).The change laws of compressive and flexural strength of recycled geopolymer specimens were investigated.And the microscopic characteristics were carried out by SEM,XRD and FTIR to observe the internal morphology and analyze changes in components of recycled geopolymers at different substitution rates.The results show that,with the increase of substitution rate of recycled geopolymer powder,the mechanical properties of recycled geopolymers degenerate and the looser structure are formed.When the substitution rate is less than 50%,the recycled geopolymer specimen meets the use requirements of heavy traffic load class.And the specimen with 80% of substitution rate satisfies the requirements of plastering mortar.     

矿渣基无机矿物聚合材料力学性能的研究

目的研究各种原材料的掺量对于矿渣基无机矿物聚合材料抗压强度的影响.方法利用矿渣,高岭土,氢氧化钾,水玻璃等原料制备矿渣基无机矿物聚合材料,并通过对比实验,在单独改变某一因素的情况下,研究矿渣基无机矿物聚合材料抗压强度的变化规律.结果随着固液比、高岭土含量、水玻璃含量和氢氧化钾含量的增加,矿渣基无机矿物聚合材料的抗压强度均呈现出先升高再降低的变化规律.结论固液比的大小在一定的范围内不会对抗压强度产生显著的影响.高岭土占固相的质量分数为20%,水玻璃占液相的质量分数为50%,氢氧化钾占固相的质量分数为18%时,材料获得了最佳的力学性能.     

Mechanical Properties of Phenolic-Resin Composites Reinforced with CF/BF Interlayer Hybrid Fibers

Phenolic-resin composites reinforced with carbon fiber (CF) and basalt fiber (BF) interlayer hybrid fibers plain fabric were fabricated. The tensile strength, compressive strength and interlaminar shear strength of the prepared composites were studied. The results indicated that hybrid fibers reinforced composites possessed the advantages of both CF and BF. When resin content was 35% by volume fraction, the comprehensive mechanical performance of BF/CF reinforced phenolic resin composites reached the optimal values with the warp and weft direction tensile strength, compressive strength and interlayer shear strength being 252 MPa and 487 MPa, 105 MPa and 129 MPa, 21 MPa and 20 MPa, respectively. The scanning electron microscope (SEM) observations showed that the BF/CF hybrid fibers reinforced composites had better interfacial adhesion.     

Properties of Chemically Synthesized Nano-geopolymer Cement based Self-Compacting Geopolymer Concrete(SCGC)

The physical and mechanical properties of self-compacting geopolymer concrete(SCGC) using chemically synthesized nano-geopolymer cement was investigated. Nano-geopolymer cement was synthesized using nano-silica, alkali activator, and sodium aluminate in the laboratory. Subsequently, nine nanogeopolymer cement sbased SCGC mixes with varying nano-geopolymer cement content, alkali activator content, coarse aggregate(CA) content, and curing temperature were produced. The workability-related fresh properties were assessed through slump flow diameter and slump flow rate measurements. Mechanical performances were evaluated through compressive strength, splitting tensile strength, and modulus of elasticity measurements. In addition, rapid chloride penetration test, water absorption, and porosity tests were also performed. It was assessed that all mix design parameters influenced the fresh and hardened properties of SCGC mixes. Based on test results, it was deduced that nano-geopolymer cement SCGC performed fairly well. All the SCGC mixes achieved the 28-day compressive strength in the range of 60-80 MPa. Additionally, all mixes attained 60% of their 28-day strength during the first three days of elevated temperature curing. FTIR and SEM analyses were performed to evaluate the degree of polymerization and the microstructure respectively for SCGC mixes.     

粉煤灰-矿渣基地聚物混凝土力学性能与微观结构

为考察不同配合比对地聚物混凝土性能的影响,开展了粉煤灰与矿渣比例、水玻璃模数以及水玻璃掺量(质量分数)对其宏观力学性能影响的实验研究,并从微观层次扫描电子显微镜(SEM)、能量弥散X射线分析(EDS)、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)以及压汞实验(MIP)对微观结构进行研究.结果表明:养护龄期的增加,...     

Preparation of fly ash and rice husk ash geopolymer

The geopolymer of fly ash (FA) and rice husk ash (RHA) was prepared. The burning temperature of rice husk, the RHA fineness and the ratio of FA to RHA were studied. The density and strength of the geopolymer mortars with RHA/FA mass ratios of 0/100, 20/80, 40/60, and 60/40 were tested. The geopolymers were activated with sodium hydroxide (NaOH), sodium silicate, and heat. It is revealed that the optimum burning temperature of RHA for making FA-RHA geopolymer is 690℃. The as-received FA and the ground RHA with 1%-5% retained on No.325 sieve are suitable source materials for making geopolymer, and the obtained compressive strengths are between 12.5-56.0 MPa and are dependent on the ratio of FA/RHA,the RHA fineness, and the ratio of so dium silicate to NaOH. Relatively high strength FA-RHA geopolymer mortars are obtained using a sodium silicate/NaOH mass ratio of 4.0, delay time before subjecting the samples to heat for 1 h, and heat curing at 60℃ for 48 h.     

Effects of Fiber Surface Pretreatment and Composite Post-treatment on Mechanical Properties of 2D-Cf/PhosphateGeopolymer Matrix Composites

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纤维表面改性和后处理对2D-碳纤维强韧磷酸盐无机聚合物复合材料力学性能的影响

何培刚^1,2，贾占林^1,2，付帅^1,2，王加涛^1,2，段小明^1,2，杨治华^1,2，贾德昌^1,2，周玉^1,2

（1哈尔滨工业大学 材料科学系，特种陶瓷研究所，哈尔滨 150001；

2 先进结构功能一体化材料与绿色制造技术工信部重点实验室，哈尔滨工业大学，哈尔滨 150001）

中文说明:

无机聚合物因其具有良好的耐热性、阻燃性、环境友好等特性受到广泛关注。然而其主要缺点为强度低、脆性大、应用可靠性差，因此需要对其进行强韧化处理。本文采用超声辅助浸渍法制备了二维连续碳纤维（Cf）增强的磷酸盐基无机聚合物复合材料，通过X射线光电子能谱（XPS），X射线衍射（XRD）和扫描电子显微镜（SEM）研究了纤维表面处理和复合材料高温处理对复合材料性能的影响。结果表明，表面处理可显著改善碳纤维和基体之间的界面相互作用，这在提高复合材料力学性能方面起着关键作用，所制备复合材料的弯曲强度和杨氏模量分别为156.1 MPa和 39.7 GPa，同时其断裂过程完全不同于无机聚合物基体，表现为伪塑性断裂特征，从而使其应用可靠性显著提高。此外，采用后续Sol-SiO2再浸渍处理可提高复合材料致密度从而进一步改善复合材料的力学性能。本文的研究结果提供了一种改善复合材料界面性能的新思路，所制备复合材料表现出较高的力学性能和非灾难性断裂特征，同时具有低温制备、高温服役的突出特性，在高马赫数飞行器多功能防热承载构件上具有潜在的应用前景。

关键词：无机聚合物，碳纤维，复合材料，表面改性，力学性能