粘合性能对短纤维-氯丁橡胶复合材料耐热性的影响

该文以尼龙短纤维为例研究了短纤维的不同用量及其粘合性能对短纤维-CR复合材料的力学性能和耐热老化性能的影响；并研究了尼龙短纤维-CR复合材料的耐溶胀性能。实验结果表明：随着尼龙短纤维用量的增加，短纤维-CR复合材料的硬度、撕裂强度、20％定伸应力不断提高；短纤维与橡胶基质的粘合好，耐溶胀性能明显提高，对橡胶的补强效果更好，复合材料的耐热老化性能提高。     

尼龙和聚酯短纤维新预处理方法及其对复合材料性能的影响

对尼龙、聚酯短纤维的几种预处理方法进行比较和优化，提出一种新的、有效的短纤维预处理方法。分析比较了预处理方法对尼龙、聚酯短纤维在胶料中的分散度、长度保持率、混炼功率、物理性能及溶胀性能的影响。认为采用新预处理方法处理的短纤维，其复合材料的各项性能均最佳，短纤维与橡胶间获得较好的粘合效果。同时提出用补强因子来定量评价预处理效果及粘合效果的方法。     

废尼龙短纤维/丙烯酸酯橡胶复合材料的性能研究

对废尼龙短纤维／丙烯酸酯橡胶复合材料中短纤维的分布状态和复合材料的性能进行了研究。结果表明,废尼龙短纤维能较好地分散在丙烯酸酯橡胶中;随短纤维用量的增大,复合材料的定伸应力和撕裂强度增大,抗溶胀性能提高,但拉伸强度减小     

尼龙和聚酯短纤维用量对其与天然橡胶和氯丁橡胶复合材料性能的影响

详细研究了尼龙和聚酯短纤维用量对尼龙－天然橡胶和聚酯－氯丁橡胶复合材料的的２０％定伸应用、拉伸强度及撕裂性能的影响。从理论上探讨拉伸强度的变化规律，其与粘合效果、基质类型等因素的依赖关系，拉伸强度的预测和拉伸破坏机理。同时提出了界面强度求解的看法。     

不同种类短纤维对天然橡胶/丁苯橡胶复合材料性能的影响

分别以尼龙66短纤维、芳纶短纤维及聚酯短纤维作为增强剂,天然橡胶（NR）和丁苯橡胶（SBR）作为基体制备了短纤维增强NR/SBR（短纤维/NR/SBR）复合材料,采用正交实验方法研究了短纤维种类、长度及用量对短纤维/NR/SBR复合材料的拉伸性能、硬度、撕裂强度的影响。结果表明,经过浸渍处理后的尼龙66短纤维与NR/SBR基体之间的结合最为紧密;浸渍处理后的尼龙66短纤维可以有效提高NR/SBR复合材料的拉伸强度,在一定范围内,随着短纤维长度和用量的增加,短纤维/NR/SBR复合材料的拉伸强度有所提高;短纤维的加入提高了NR/SBR复合材料的撕裂强度和硬度,但扯断伸长率则有所下降。     

短纤维在氯丁橡胶中的应用

研究了短纤维种类、用量及长度对短纤维/氯丁橡胶复合材料的纤维取向、纤维分散、力学性能、耐热性能以及溶胀性能的影响。结果表明,复合材料呈现明显的各向异性;3mm短纤维/氯丁橡胶(CR)复合材料的纤维取向度、拉伸强度、撕裂强度和耐溶胀性能均优于1mm复合材料,短纤维分散性对复合材料耐热性的影响较小。     

短纤维新预处理方法对短纤维-橡胶复合材料界面结构的影响及粘合机理

通过扫描电镜，透射电镜、红外光谱、应力－应变曲线等进一步研究了新法预处理尼龙，聚酯短纤维－橡胶复合材料的界面形态，认为新预处理方法能使尼龙，聚酯短纤维与基质间形成牢固的界面层，使应力良好地向短纤维传递，从而充分发挥短纤维的补强作用。最佳粘合剂用量与纤维长度之间存在一个平衡值。     

预处理PA6短纤维与橡胶复合材料的研究

用一种新方法处理的尼龙－６短纤维与橡胶复合，研究了纤维的分散性，长度保持率，取向参数及粘合性能与复合材料抗溶胀性和宏观力学性能的关系。提出了制约该复合体系力学性能的关键是纤维的分散性的观点，并对该复合体系的临界体积分数及断裂机理提出了见解。     

短纤维补强氯丁橡胶的性能研究

研究短纤维种类和用量对短纤维/氯丁橡胶(CR)复合材料中短纤维取向和分散以及复合材料粘合性能和溶胀性能的影响.结果表明:随着短纤维用量的增大,短纤维/CR复合材料的相对交联密度和短纤维取向度均增大,抗溶胀性能提高,取向度大小顺序为芳纶短纤维、聚酯短纤维、锦纶66短纤维和短切棉纤维;聚酯纤维与CR基体的粘合性能最差,短切棉纤维在CR中分散性最差;短纤维/CR复合材料的性能呈现出明显的各向异性.     

短纤维新预处理方法对短纤维－橡胶复合材料界面结构的影响及粘合机理

通过扫描电镜、透射电镜、红外光谱、应力一应变曲线等进一步研究了新法预处理尼龙、聚酯短纤维－橡胶复合材料的界面形态。认为新预处理方法能使尼龙、聚酯短纤维与基质间形成牢固的界面层．使应力良好地向短纤维传递．从而充分发挥短纤维的补强作用。最佳粘合剂用量与纤维长度之间存在一个平衡值。     

Effect of Impact Modifier Types on Mechanical Properties of Rubber‐Toughened Glass‐Fibre‐Reinforced­ Nylon 66

The effect of adding rubber on the properties of glass‐fibre‐filled nylon 66 was investigated in this study. Styrene‐Ethylene‐Butylene‐Styrene and Ethylene‐Propylene elastomers grafted with maleic anhydride (SEBS‐g‐MA and EP‐g‐MA, respectively) were used to toughen the nylon‐matrix composites. Impact strength and elongation at break were found to increase with increasing rubber content, but flexural strength, tensile strength and stiffness decreased; however, by adding moderate amounts of rubber to glass‐fibre‐reinforced nylon 66, a desirable balance between stiffness and toughness of the material may be obtained. For example, the addition of 10 wt.% of SEBS‐g‐MA to nylon 66 with 23.62 wt.% glass fibre loading resulted in 28.3% and 167% increase in tensile strength and impact strength of the composites, respectively, when compared to neat nylon 66. This suggests that combining both glass fibres and rubber with nylon 66 is a useful strategy to optimize and enhance the properties of nylon 66. The procedure may be used to recycle polyamides, in general, and to develop components for under‐the‐hood automotive applications, in particular.     

聚酯短纤维/CR复合材料补强机理的研究

以不同直径、相同长径比的聚酯短纤维补强CR复合材料为研究对象，采用扫描电子显微镜观察、应力—应变曲线分析等手段，研究了复合材料的补强机理及破坏形式。结果发现，屈服强度由薄弱界面的剪切强度决定，而界面的剪切强度则取决于界面粘合、短纤维长度、直径以及含量等因素s拉伸过程中复合材料的界面按照剪切强度由小到大的顺序分段依次被破坏直至断裂；短纤维含量较低时，其拉伸强度主要由短纤维拨出后的基体承担，同时受应力集中影响很大，短纤维含量较高时断裂强度则更接近于屈服强度。     

氧化处理对MC尼龙/C3D复合材料摩擦磨损性能的影响

以己内酰胺单体和经氧化处理的碳纤维三维编织物(C3D)为原料,采用原位聚合方法制备了C3D增强浇铸尼龙(MC尼龙/C3D)复合材料。在磨损试验机上进行了滑动摩擦试验,采用扫描电子显微镜对磨痕和磨屑形貌进行观察和分析,研究了氧化处理对MC尼龙/C3D复合材料摩擦学性能的影响。结果表明,C3D经过氧化处理后所制MC尼龙/C3D复合材料的摩擦系数明显小于C3D未经氧化处理的MC尼龙/C3D复合材料。随着载荷的增加,材料的摩擦系数增大,而磨损率减小;在较高滑动速度下,摩擦系数和磨损率均较小;从磨痕和磨屑形貌观察到,C3D经氧化处理后与基体结合好,而未经氧化处理的C3D与基体剥离,但是C3D经氧化处理的复合材料的磨损率在较高载荷下略有增大。表明,C3D的氧化处理提高了碳纤维与基体间的结合强度,同时在一定程度上提高了复合材料的摩擦学性能。     

Properties of nylon-6-based composite reinforced with coconut shell particles and empty fruit bunch fibres

Novel natural fibre composites of nylon-6 reinforced with coconut shell (CS) particles and empty fruit bunch (EFB) fibres have been investigated. Fillers were alkali treated before melt compounding with nylon-6. Mechanical, thermal and rheological properties of composites were measured. Tensile modulus was found to improve with both fillers up to 16% for nylon-6/CS composite and 10% for nylon-6/EFB composite, whereas a moderate increase in tensile strength was observed only with CS composites. Differences in the strengthening mechanisms were explained by the morphology of the two fillers, empty fruit bunch fibres having a weaker cellular internal structure. Observation of composite morphology using SEM showed that both fillers were highly compatible with nylon-6 due to its hydrophilic nature. Both fillers were found to cause a slight drop in crystallinity of the nylon matrix and to lower melt viscosity at typical injection moulding strain rates. Moisture absorption increased with addition of both fillers.     

Fabrication of short carbon fibre reinforced SiC multilayer composites by tape casting

Silicon carbide multilayer composites containing short carbon fibres (C_sf/SiC) were prepared by tape casting and pressureless sintering. C fibres were dispersed in solvents and then mixed with SiC slurry to make green C_sf/SiC tape. Triton X-100 was found to be the best one for Toho Tenax HTC124 fibres (with water soluble coating) among BYK-163, BYK-410, BYK-2150, BYK-9076, BYK-9077 and Triton X-100 dispersants. C_sf/SiC multilayer composites containing 5 vol.% fibre (mean fibre length of 3, 4.5, and 6 mm) were obtained. Addition of short C fibres seems to worsen the densification process in the C_sf/SiC multilayer composites, whereas anisotropy shrinkage in C_sf/SiC was also observed. Open pores size was increased slightly after the addition of C fibre but it decreased with the mean fibre length. Mechanical properties were affected by high residual porosity. The addition of short C fibre has not changed the crack deflection at weak interfaces. C_sf/SiC multilayer composites containing longer fibres (4.5 and 6 mm) presented higher elastic modulus, bending strength and Vickers hardness as compared to shorter fibres (3 mm). Improved sintering performance and fibre content are necessary to improve mechanical properties.     

Effect of alkali treatment on properties of unidirectional isora fibre reinforced epoxy composites

Abstract

Unidirectional isora fibre reinforced epoxy composites were prepared by compression moulding. Isora is a natural bast fibre separated from Helicteres isora plant by retting process. The effect of alkali treatment on the properties of the fibre was studied by scanning electron microscopy (SEM), IR, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Mechanical properties such as tensile strength, Young's modulus, flexural strength, flexural modulus and impact strength of the composites containing untreated and alkali treated fibres have been studied as a function of fibre loading. The optimum fibre loading for tensile properties of the untreated fibre composite was found to be 49% by volume and for flexural properties the loading was optimised at ～45%. Impact strength of the composite increased with increase in fibre loading and remained constant at a fibre loading of 54·5%. Alkali treated fibre composite showed improved thermal and mechanical properties compared to untreated fibre composite. From dynamic mechanical analysis (DMA) studies it was observed that the alkali treated fibre composites have higher E' and low tan δ maximum values compared to untreated fibre composites. From swelling studies in methyl ethyl ketone it was observed that the mole percentage of uptake of the solvent by the treated fibre composites is less than that by the untreated fibre composites. From these results it can be concluded that in composites containing alkalised fibres there is enhanced interfacial adhesion between the fibre and the matrix leading to better properties, compared to untreated fibre composites.     

桦木纤维/不饱和聚酯复合材料制备与性能研究

采用硅烷偶联剂、乙醇和水等分别对桦木纤维(BF)和回收纸浆纤维进行表面处理,并分别将改性纤维作为不饱和聚酯树脂(UPR)的增强材料,制备相应的BF/UPR复合材料。研究了不同改性方法对复合材料界面性能的影响。结果表明:不同纤维种类、不同纤维表面处理方法和不同纤维用量对复合材料的界面性能、力学性能等影响较大;经硅烷偶联剂处理后的BF,可有效改善BF与UPR之间的界面相容性;当w(偶联剂处理BF)=16%时,相应复合材料的拉伸强度和冲击强度比纯UPR体系分别提高了31.0%和28.5%;在制备回收纤维/UPR复合材料之前应先对回收材料进行筛选,并且应优先选择对UPR基体树脂具有明显增强作用的回收纤维。     

Effect of silane treatment on the Curaua fibre/polyester interface

ABSTRACT

Good adhesion at fibre/matrix interface of lignocellulosic fibres is crucial when substituting synthetic fibres in polymer composites. The great variability presented by those fibres requires diverse characterisation studies for better insights on fibre surface treatments and resin systems interactions. In this work, Curaua fibres were treated using silane coupling agents to improve their interfacial properties with polyester. The fibres were pre-treated using 4?wt% solution of NaOH and then treated with 5?wt% solution of (3-aminopropyl) trimethoxysilane (AMPTS) or triethoxymethylsilane (TEMS). Characterisation of the treated fibres was carried out using infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. Fibre wettability and adhesion towards polyester was investigated using contact angle measurements and pull-out tests, respectively. The AMPTS treatment yielded a significant result of 20.2?MPa in interfacial shear strength (≈2.5 times that of the untreated fibre), attributed to the increase in availability of binding sites with polyester.