玻璃纤维增强氯氧镁水泥

玻璃纤维增强氯氧镁水泥制品是用菱苦土和氯化镁水溶液制成的水泥中,加入玻璃纤维作增强材料制成的制品。这是随玻璃纤维开发而发展起来的一种新型材料。目前玻璃纤维增强氯氧镁水泥制品已从轻型屋面材料单一品种发展到复合地板、琉璃瓦、浴缸、风管、风道等众多品种。据有关方面分析预测,如果玻璃纤维增强氯氧镁水泥瓦在吸水率、耐老化及制品强度方面得到改进,     

玻纤/改性氯氧镁水泥复合材料性能研究及应用

着重研究玻纤/改性氯氧镁水泥复合材料的性能,分析了玻纤/氯氧镁水泥复合材料耐水性差的原因,阐述了改性的必要性和在建筑上应用的优越性。     

玻璃纤维增强氯氧镁水泥的耐久性及其性能退化机理

采用热水加速老化试验和SIC(Strand in cement)试验方法研究玻璃纤维增强氯氧镁水泥(Glass fiber reinforced magnesium oxychloride cement,GRMC)的耐久性.通过分析试件的抗弯强度和变形特性,研究了50 ℃和80 ℃热水条件下GRMC加速老化的力学性能退化规律.运用X射线衍射仪(XRD)分析微观物相组成,并结合扫描电镜(SEM)观察老化过程中玻璃纤维在氯氧镁水泥基体中的腐蚀情况,分析其性能退化机理.结果表明,导致GRMC性能退化的主要因素是基体性能退化及由此造成的基体-纤维界面区的结构松散;次要因素是纤维腐蚀.纤维腐蚀程度与水泥基体性能有直接关系,若水泥基体的物相组成发生变化,玻璃纤维会发生化学腐蚀,导致材料性能下降.试验结果也显示抗水改性是提高GRMC耐久性的有效方法.     

铝酸盐矿物对氯氧镁水泥的影响

本讨论了铝酸盐矿物对氯氧镁水泥的水化产物、耐水性和强度的影响。通过ＸＲＤ相分析，证明了具有水化活性的铝酸盐矿物（如ＣＡ，Ｃ４ＡＦ等）对氯氧镁水泥的水化相有影响；而没有水化活性的铝酸盐矿物（如Ｃ２ＡＳ）对氯氧镁水泥的水化相没有影响。当氯氧镁水泥中ＭｇＯ／ＭｇＣｌ２摩尔比大于５时，含有ＣＡ或Ｃ４ＡＦ的净浆硬化体中主要水化相是３·１·８相，而不含ＣＡ或Ｃ４ＡＦ或含Ｃ２ＡＳ的净浆硬化体中主要水化相是５·     

无机玻璃钢风管在通风空调工程中的应用

无机玻璃钢风管，又称玻璃纤维氯氧镁水泥通风管。     

氯氧镁水泥耐水性及其改善的研究

对氯氧鲜水泥不耐水的原因及其改善机理，方法、抗水处加剂的研究现状进行了评术。认为水对水化物的水解作用是其不耐水的根本原因；掺加磷酸系外加剂对改善氯氧镁水泥的耐水性是很有效的，共改善机理可其对水化物水解反应的影响有关。讨论了氯氧镁水泥耐水的评价方法，并对今后的研究提出了几个尚需深入的方面。     

初始水量对氯氧镁水泥生产工艺的影响

介绍了利用氧化镁、氯化镁以及碳酸钙为原料制备氯氧镁水泥的过程,研究了初始水量对生产工艺的影响,测定了氯氧镁水泥的表观粘度和固化时间,得到了最佳工艺条件为初始水量H2O/MgCl2(摩尔比)=15,固化时间为40 min,浆体适合于注射成型.该研究为氯氧镁水泥生产控制提供了理论和实践依据.     

硫、氯氧镁混合胶凝体系凝结硬化性能及微观结构

为了改善镁质胶凝材料的性能,结合硫氧镁水泥和氯氧镁水泥两个体系的特性,制备了硫、氯氧镁混合胶凝体系.通过测试凝结时间、抗压和抗折强度对混合体系的凝结硬化性能及耐水性进行了研究,利用XRD、SEM和EDS分析表征手段对混合体系水化产物的物相组成、元素分布及微观形貌进行了分析.结果表明:溶液中氯化镁质量分数增加,浆体的凝结时间延长,当氯化镁质量分数大于70％,凝结时间缩短.与硫氧镁水泥和氯氧镁水泥相比,混合体系的抗压强度降低、抗折强度稍有增加,浸泡28d后表现出了良好的耐水性.XRD和SEM数据表明:晶体之间没有形成连结力强的连续结构,使混合体系的力学性能降低.浸水后水化产物微观形貌的改变是混合体系耐水性增加的主要原因.     

利用沙漠沙制备氯氧镁水泥新型复合材料的研究进展

氯氧镁水泥具有凝结硬化快、硬度高等优点,但是过高的制备成本限制了其大范围推广应用。利用有机和无机材料作为外加剂可以降低氯氧镁水泥的成本,但是效果却参差不齐。利用沙漠沙制备氯氧镁水泥复合材料,是近些年防沙治沙新材料制作的重要手段。本文综述了不同比例沙漠沙掺量对氯氧镁水泥结构特征、力学强度、耐水性和抗压强度的影响,并指明了沙漠沙制备氯氧镁水泥材料研究中存在的问题,提出未来发展趋势,以期为深入研究沙漠沙制备氯氧镁水泥新型复合材料提供参考。     

氯氧镁水泥的研究进展

本文综述了氯氧镁水泥的研究进展,介绍了氯氧镁水泥的各种优异的性能、缺陷和相变机理,总结了氯氧镁水泥的改性方法及其制品的开发利用的情况。     

短切纤维在增强热塑性树脂上的应用

介绍了短切纤维增强后的热塑性树脂在机械强度、热稳定性、电性能等性能上的较大提升,短切纤维质量要求与控制,流动性的检测方法,复合材料应用中浸润剂的选择,短切纤维的浸润剂和纤维长度这两个因素对于增强热塑性树脂性能的影响,短切纤维对塑料改型的作用和特点,GFRTP的发展方向。     

没食子酸/乙二胺共沉积聚酯纤维制备及其成纸性能

赋予疏水性聚酯短切纤维亲水性能，可拓展其应用价值。本文提出在碱性Tris缓冲液中，使没食子酸与乙二胺通过迈克尔加成或席夫碱反应共沉积在聚酯短切纤维表面。测定了改性前后聚酯短切纤维的动态接触角，采用扫描电子显微镜（SEM）观察了纤维的微观形貌，利用傅里叶变换红外光谱（FT-IR）和X射线光电子能谱（XPS）表征了纤维表面结构的变化，最后以改性前后聚酯短切纤维和阔叶木浆抄纸，测定了纸张的孔径分布变化和透气性，并测试了纸张物理性能。结果表明：经共沉积改性后的聚酯短切纤维表面存在大量羟基，纤维表面有氮元素生成，同时表面粗糙度提高，与未改性聚酯短切纤维相比，改性后聚酯短切纤维与去离子水的接触角降低了57.2?，显著改善了纤维亲水性；与未改性纤维纸页相比，改性后纤维纸页抗张强度提高35.2%，湿强度提高43.3%，透气度提高11.1%，相同孔径范围内孔径增加了24%-30%，纤维分散性明显提高。本研究成果可制得亲水性优良的聚酯纤维，并可用于高性能纸张的应用。     

黄麻纤维增强聚丙烯的力学性能

本文讨论了注塑成型黄麻纤维增强聚丙烯的制备方法和力学性能.将纤维重量含量分别为10%、20%和30%的复合材料进行比较,分析纤维含量对复合材料拉伸、弯曲和冲击性能的影响;将纤维分别切成约3mm、5mm和10mm长制成复合材料进行比较,分析纤维长度对复合材料拉伸、弯曲和冲击性能的影响.掺入黄麻纤维能使聚丙烯的拉伸和弯曲性能提高,但使其冲击强度降低;随纤维含量的增加或纤维长度的增加,复合材料的强度和模量是递增的,而冲击强度是递减的.     

玄武岩纤维用于国内摩擦材料的可行性研究

将试制的玄武岩短切纤维进行了配方试验和性能测试.分析玄武岩纤维在国内摩擦材料中的应用前景,介绍了玄武岩纤维在摩擦材料中的应用.通过对玄武岩短切纤维增强制动片的检测认为其适合作为摩擦材料的增强材料.     

Preferred orientation of chopped fibers in polymer-based composites processed by selective laser sintering and fused deposition modeling: Effects on mechanical properties

The orientation of reinforcing fibers in polymer-based composites greatly affects their mechanical features. It is known that different orientations of continuous fibers in the stacked layers of a laminate play a crucial role in providing an isotropic mechanical behavior, while the alignment of chopped fibers in injection molding of composites results in a degree of anisotropy. Recent additive manufacturing techniques have offered a way of controlling the fiber orientation. This article aims to investigate the effect of fiber orientation on the mechanical properties of polyamide/carbon fiber composites processed by fused deposition modeling and selective laser sintering. Tensile samples which had different fibers and layer interface with respect to the sample axis (and therefore to the tensile load) were produced. Tensile tests were performed at different strain rates; the tensile properties and the fracture surface morphology were correlated with the processing method and the sample microstructure. The best strength and stiffness were observed when the fibers and the layer interfaces were parallel to the sample axis.     

对位芳纶短纤维/氢化丁腈橡胶复合材料的制备及其结构性能

采用综合性能优异的氢化丁腈橡胶(HNBR)和耐高温对位芳纶短纤维复合,制备了高强度、高模量和耐高温的复合材料,比较了芳纶短纤维类型、纤维用量等对复合材料力学性能和流变行为的影响。结果表明,芳纶浆粕(PPTA-pulp)比芳纶短切纤维(DCF)对橡胶有更佳的增强效果,二者都能明显提高HNBR的高温强度,但PPTA-pulp的效果更为明显。PPTA-pulp增强橡胶复合材料的挤出物外观性能也较DCF增强橡胶复合材料好。     

Piezoresistive behavior of epoxy matrix‐carbon fiber composites with different reinforcement arrangements

In this work, the self‐monitoring capability of epoxy matrix‐carbon fiber composites has been studied. Different concentrations and arrangements of reinforcements were used, including random chopped, unidirectional and bi‐directional continuous carbon fibers, weaved and nonweaved. Mechanical properties were determined by uniaxial tensile tests. The composite electric to mechanical behavior was established by determining its electrical resistivity variation as a function of the stress‐strain curve. It was observed that the composites electrical resistance increased during tensile tests, a trend that indicates piezoresistive behavior. The increase was linear for the chopped reinforced composites, while it exhibits different slopes in the continuous reinforced composites. The initial smaller slope corresponds mainly to separation of the 90° oriented fibers and/or transversal cracking of the matrix, whereas the latter higher slope is caused by fiber fracture. The results demonstrated how each reinforcement configuration exhibited a unique and typical electrical response depending on the specific reinforcement, which might be appropriate either for strain‐monitoring or damage‐monitoring. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Using PyC coated short chopped carbon fiber to tackle the dilemma between toughness and strength of ZrC-SiC

Graceful toughness and high strength are mutually exclusive in engineering ZrC-SiC ceramic, which are hard to be possessed simultaneously. Here, the pyrolytic carbon (PyC) coated short chopped carbon fibers were utilized to toughen ZrC-SiC ceramic, tackling the dilemma between toughness and strength. Through the uniform incorporation of PyC coated short chopped carbon fibers, the penetration crack mode of ZrC-SiC was changed into an obviously deflecting propagation path with closed phenomenon. The PyC coating brought about a relatively weak interface bonding and guided the crack propagate along the weak interface, consequently resulting in a more flexuous crack propagation instead of passing through the fibers directly. Meanwhile, the fibers received effective protection of coating inhibiting from performance degradation. The PyC coated C_f/ZrC-SiC obtained a fracture toughness highly reaching 7.57?±?0.33?MPa?m^1/2 with a rivaling flexural strength at 268?±?16?MPa. Moreover, the graceful load-displacement curve is illustrated with a smoothly extended displacement of 0.12?mm and increased load to 83?N, which forms an obvious yield plateau. To some degree, this work provided an effective solution to tackling the dilemma between toughness and strength of engineering ZrC-SiC ceramic.     

MC尼龙—碳纤维复合材料的制备

在单体浇铸尼龙的聚合过程中加入１０％各向同性沥青基短切碳纤维，研究了温度及催化剂和活化剂用量对聚合的影响，结果表明：这些参数对聚合物相对分子质量影响很大，而空气湿度对聚合的干扰更为严重；对聚合物的性能测试显示：该尼龙导热系数明显提高，耐压缩性和抗弯曲性得到改善，抗冲击强度有所下降。     

Fabrication and mechanical properties of glass fiber‐reinforced wood plastic hybrid composites

To fully utilize the resource in the municipal solid waste (MSW) and improve the strength and toughness of wood plastic composites, glass fiber (GF)‐reinforced wood plastic hybrid composites (GWPCs) were prepared through compounding of recycled high‐density polyethylene (HDPE) from MSW, waste wood fibers, and chopped GF. Mechanical tests of GWPCs specimens with varying amounts of GF content were carried out and the impact fractured surface of GWPCs was observed through scanning electron microscope (SEM). The tensile strength of GWPCs and the efficiency coefficient values were predicted by Kelly‐Tyson method. The results indicated that the tensile strength and impact strength of GWPCs could be improved simultaneously by adding type L chopped GF (L‐GF), and would be dropped down when type S chopped GF (S‐GF) was included. The tensile strength of GWPCs was well accordant with the experimental result. The efficiency coefficient values of S‐GF and L‐GF are ?0.19 and 0.63, respectively. Inspection of SEM micrographs indicated that L‐GF had achieved full adhesion with the plastic matrix through addition of maleic anhydride‐g‐polyethylene. The main fracture modes of GWPCs included pullout of GF, broken of matrix, and interfacial debonding. Because of the synergistic effects between hybrid components in GF/wood fiber/HDPE hybrid system, a special 3D network microstructure was formed, which was the main contribution to the significant improvement in the tensile strength and impact strength of L‐GF‐reinforced hybrid composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009