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1.
概述了化学灌浆的发展现状以及化学灌浆材料的特点,介绍了常见防渗堵漏类和补强加固类的化学灌浆材料,选取最新的科研实例来说明化学灌浆材料发展与应用状况。总结了化学灌浆材料的优缺点,并对今后化学灌浆材料的发展做出了展望。  相似文献   

2.
本文对木纤维作增强填料填充低密度聚乙烯(LDPE)所获得的生物降解复合材料力学性能进行了研究.分别用四种不同的偶联剂:改性钛酸酯类偶联剂TC-POT、TC-PBT和硅烷类偶联剂γ-(2,3环氧丙氧基)丙基三甲基硅烷(KH-560)、甲基乙烯基硅烷(205-Silane)处理水纤维,经实验发现用改性钛酸酯类偶联剂TC-POT、TC-PBT处理的木纤维对低密度聚乙烯(LDPE)具有较好增强作用,所组成的复合材料具有较好的力学性能.本文也研究了不同偶联刘含量处理木纤维对复合材料力学性能的影响。  相似文献   

3.
废轮胎中试回转窑热解炭理化特性及应用前景   总被引:1,自引:4,他引:1  
采用中试回转窑热解装置对废轮胎进行了热解研究。在450 ℃~650 ℃温度范围内,热解炭的产率约为39%~44%,并具有高灰分(12%以上)和高硫含量特性。热解炭孔容积随热解温度升高而增大,并在550 ℃时达到最大值。在孔径约为50 nm处,热解炭的比孔容积具有最大值。热解炭在CO2和水蒸气气氛下,经活化可得到中等比表面积的活性炭(253 m2/g~306 m2/g),并具有较发达的中、大孔结构。热解炭及其活性炭对亚甲基兰和Pb2+具有良好的吸附性。热解炭作为炭黑使用时,其炭黑特性(结构性等)和硫化胶特性低于高补强N330炭黑。热解炭黑可用作中、低补强性炭黑。  相似文献   

4.
橡胶补强填料的研究进展   总被引:1,自引:0,他引:1  
随着汽车行业的发展,在"安全、环保和节能"方面,对轮胎的性能提出了更高的要求,因此对轮胎原料—橡胶的补强研究越来越多。本文详细介绍了补强填料补强橡胶的机理、补强填料的分类及改性途径,概述了传统补强填料炭黑、白炭黑及炭黑/白炭黑双向填料的性能和研究现状,综述了新型补强填料硅酸盐类、碳酸盐类及其它常用新型种类和性能,指出新型填料拓展了橡胶补强技术和功能橡胶材料领域的研究思路,应加强橡胶补强填料的开发、补强机理探讨和拓展补强复合材料的表征和检测手段,以满足橡胶行业发展的需求。  相似文献   

5.
采用廉价的三苯基氧膦和混酸合成了一种含磷二胺单体,二(3-氨基苯基)苯基膦氧(DAPPO)。在4,4′-二胺基二苯醚(ODA)、3,3′,4,4′-联苯四酸二酐(BPDA)和均苯四酸二酐(PMDA)聚合体系中引入该单体,制备含磷聚酰亚胺纤维。热失重分析(TGA)结果表明,聚酰亚胺纤维的热稳定性随含磷量的增加而明显提高。当n(DAPPO):n(ODA)为7:93时,纤维的极限氧指数达到了43,说明纤维的阻燃性能显著提高。  相似文献   

6.
采用静电纺丝方法制备了不同含量的偏氟乙烯和三氟乙烯的共聚物(P(VDF—TrFE))纳米纤维薄膜。通过P(VDF—TrFE)纳米纤维薄膜和柔性电极的结合,设计制作了一种针对医疗和服饰等领域应用的新型柔性压力传感器。利用扫描电镜和X射线衍射分析的方法分别对P(VDF—TrFE)纳米纤维的形貌和晶体结构进行了表征,并通过自制的测试系统获得了柔性压力传感器的灵敏度。结果表明:静电纺丝得到的纳米纤维具有较高的结晶度和β相结晶含量,其中P(VDF—TrFE)(n(VDF)/n(TrFE)=77/23)纳米纤维的口相结晶含量达到了51.3%,同时这种纳米纤维薄膜具有柔软、透气和生物相容性好等优点;基于电纺纳米纤维的柔性压力传感器具有良好的响应性能。P(VDF—TrFE)(T/(VDF)/n(TrFE)=77/23)压力传感器具有最高为60.5mV/N的灵敏度,接近于其塑性薄膜传感器,但塑性薄膜传感器的柔软性和透气性较差  相似文献   

7.
碳酸钙与碳化硅对室温硫化硅橡胶的补强作用   总被引:22,自引:0,他引:22  
在有关硅橡胶补强的研究中,人们已经对SiO2 等补强性填料对硅橡胶的补强作用进行了深入的研究,但对非补强填料对室温硫化硅橡胶的补强作用则相对涉及较少.作者研究了CaCO3 和SiC 两类非补强性填料以及填料的粒径与分布对室温硫化硅橡胶拉伸强度、断裂伸长率和耐温性能等的影响,发现合适粒径的非补强性填料对室温硫化硅橡胶有较好的补强效果,且在填料粒径及分布匹配时有最好的补强效果,选用SiC时还可以有效提高室温硫化硅橡胶的热稳定性.  相似文献   

8.
煤焦油沥青基炭纤维(CPCF)价格低廉含炭量高、易于活化,是制备纤维状活性炭(CPACF)的优良原料。本文讨论了CPCF的抗拉强度和活化条件对CPACF比表面积的影响。并同石油系沥青基炭纤维(PPCF)进行了比较。考察了不同比表面积的CPACF、PPACF和商品用颗粒活性炭(AC)对0.1mol/L碘溶液、0.005mol/L亚早兰溶液和293K下三氯甲烷饱和蒸汽的吸附性能,及以上三样品在293K  相似文献   

9.
采用环境友好的一步水热法,以GeSe4玻璃为原料,水溶液为反应介质,在80℃合成三方相硒(t-Se)一维纳米结构。用透射电子显微镜(TEM)、拉曼光谱(Raman)、扫描电子显微镜(SEM)、原子力显微镜(AFM)等手段表征了一维Se纳米纤维的形貌和结构。结果表明,合成的Se纤维沿t-Se的[001]方向生长,截面为六边形。反应144 h后,纤维长度达到毫米级,平均直径为1~5 μm。对合成的Se纤维进行纳米压痕实验,测得其硬度和弹性模量分别为(399.5±20.4)MPa和(1.13±0.05)GPa。在pH=12.0的NaOH溶液(80℃)中,Se纳米纤维生长速度高于酸性(pH=3.3)和中性(pH=6.3)介质,反应24 h后,纤维平均长度和直径达到344和1.12 μm。  相似文献   

10.
薄层色谱法分析酸性和阳离子染料   总被引:2,自引:0,他引:2  
史晓凡  王景翰  张忠伟 《色谱》1999,17(5):503-505
用相关系数法从多种展开剂中优选出酸性、阳离子染料薄层色谱分析的最佳展开剂。在相关系数最小的两种展开剂V(正丁醇)∶V(冰乙酸)∶V(水)=2∶1∶5和V(乙酸乙酯)∶V(冰乙酸)∶V(水)=50∶15∶10中,相同颜色的毛、腈纶纤维上的酸性、阳离子染料提取液及不同厂家生产的同一种染料均得到了很好的鉴别。  相似文献   

11.
以广州东镜新城一期会所梁粘贴碳纤维为例,对碳纤维施工过程中的施工材料、工艺及质量控制、施工组织、质量保证、安全措施等进行了阐述和总结。  相似文献   

12.
A process was developed for preparing a polymeric composite material by combining the synthesis of the oligomer with its reinforcement with basalt fiber. The advantage of this process relative to the traditional technology is more efficient interaction of the oligomer with the basalt fibers, positively affecting the composite formation and ensuring improved physicochemical and mechanical properties of the basalt-reinforced plastics.  相似文献   

13.
Isotactic polypropylene (iPP) composite with two‐scale reinforcement structure, i.e. nanoscale shish–kebab structure and micron‐scale glass fiber (GF) with orientation, was fabricated by an oscillatory shear injection molding (OSIM) technology. The oscillatory shear flow provided by the OSIM gave rise to a high fraction of shish–kebab structures in the iPP composite, characterized by X‐ray scattering technique. On the other hand, the oscillatory shear flow oriented GFs in the iPP composite, which was revealed by scanning electron microscopy measurement. The iPP composite with this two‐scale reinforcement structure exhibited simultaneously remarkably enhanced tensile strength and impact strength. Fracture mechanism of this iPP composite was also proposed. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

14.
A computer model is presented for the study of the effects of fiber characteristics on the mechanical properties of short-fiber-reinforced composites. Our model results indicate a very weak effect of fiber orientation on the modulus and tensile strength of the composite. Very high levels of orientation are required before a true reinforcement of the composite by the fiber can occur. For randomly dispersed fibers, our results point to the presence of an optimum fiber aspect ratio for effective reinforcement. They also indicate a microfailure mechanism which originates at the fiber ends and propagates along the fiber-matrix interface, with no fiber breaking being involved. Our model results are compared with predictions from other theories and available experimental data. © 1994 John Wiley & Sons, Inc.  相似文献   

15.
The main objective of this article is to introduce a newly identified fish tail palm tree natural fiber as reinforcement in the development of partially biodegradable green composites. The tensile strength, tensile modulus, and impact strength of the composite are 1.54, 1.83, and 9.8 times greater than those of pure resin, respectively. The thermal conductivity of the composite decreased with increase in fiber content and the opposite trend was observed for temperature. The effect of temperature on specific heat capacity and thermal diffusivity of the composite was also considered and discussed.  相似文献   

16.
The research article focused on the effect of wood sawdust as secondary filler reinforcement in Indian mallow fiber yarn mat reinforced with polyester composites. Composites were fabricated along the transverse and longitudinal orientation in six different combinations by compression molding machine. The mechanical properties of composites by single and double layer yarn mat with and without wood sawdust filler were evaluated while loading composites specimen on warp and weft direction at the first time in this research paper. The Indian mallow fiber double layer longitudinal orientation yarn mat/wood sawdust filler/polyester composite specimen along the warp direction was found to exhibit optimum mechanical properties compared to other composites. Furthermore, the Indian mallow fiber yarn mat composites were fabricated with helmet and civil construction pipes at first time in this work to replace the synthetic fiber through natural fiber. Scanning electron microscopy was performed to study the morphologies of internal crack and fractured surface of composites.  相似文献   

17.
介绍了PBO(聚对苯撑苯并双噁唑)纤维的结构与性能,并针对该纤维作为复合材料增强体与树脂界面粘结性差的特点,评述了PBO纤维表面改性技术中的化学法、共聚改性、偶联剂处理、等离子处理、电晕处理和辐射处理法的研究进展,并比较了各种方法的改性效果及各自优缺点。  相似文献   

18.
Using trihydroxy polyether polyol (PPG), diphenylmethane diisocyanate (MDI) as soft segment and hard segment, carbon fiber (CF) as reinforcement, and self-crosslinking CF/polymethyl methacrylate (PMMA) composite was prepared by prepolymer method. In this study, starch and octanoyl chloride were esterified to obtain esterified starch (SE). The fiber is then melt blended with PMMA matrix to prepare PMMA composite. Fourier-transform infrared spectroscopy (FTIR) and SEM were used to analyze and characterize the composites produced. The results show that the composite material was prepared by separately modifying the fiber with NaOH and SE, respectively. The mechanical properties of the composite materials prepared by the modified fiber are improved, and the fiber and the PMMA matrix showed better compatibility. The mechanism of comodified fiber enhanced the mechanical properties of its composites.  相似文献   

19.
The natural fibers such as jute, coir, hemp, sisal etc. are randomly used as reinforcements for composite materials because of its various advantages such as low cost, low densities, low energy consumption over conventional fibers. In addition, they are renewable as well as biodegradable, and indeed wide varieties of fibers are locally available. In this study, glass–jute fiber reinforced polymer composite is fabricated, and the mechanical properties such as tensile, flexural and impact behavior are investigated. The materials selected for the studies were jute fiber and glass fiber as the reinforcement and epoxy resin as the matrix. The hand lay‐out technique was used to fabricate these composites. Fractured surface were comprehensively examined in scanning electron microscope (SEM) to determine the microscopic fracture mode. A numerical procedure based on the finite element method was then applied to evaluate the overall behavior of this composite using the experimentally applied load. Results showed that by incorporating the optimum amount of jute fibers, the overall strength of glass fiber reinforced composite can be increased and cost saving of more than 30% can be achieved. It can thus be inferred that jute fiber can be a very potential candidate in making of composites, especially for partial replacement of high‐cost glass fibers for low load bearing applications. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

20.
In this work, the technology of nano‐ and micro‐scale particle reinforcement concerning various polymeric fiber‐reinforced systems including polyamides (PAs), polyesters, polyurethanes (PUs), polypropylenes (pps), and high‐performance/temperature engineering polymers such as polyimide (PI), poly(ether ether ketone) (PEEK), polyarylacetylene (PAA), and poly p‐phenylene benzobisoxazole (PBO) is reviewed. When the diameters of polymer fiber materials are shrunk from micrometers to submicrons or nanometers, there appear several unique characteristics such as very large surface area to volume ratio (this ratio for a nanofiber can be as large as 103 times of that of a microfiber), flexibility in surface functionalities and superior mechanical performance (such as stiffness and tensile strength) compared to any other known form of the material. While nanoparticle reinforcement of fiber‐reinforced composites has been shown to be a possibility, much work remains to be performed in order to understand how nanoreinforcement results in dramatic changes in material properties. The understanding of these phenomena will facilitate their extension to the reinforcement of more complicated anisotropic structures and advanced polymeric composite systems. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

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