木纤维增强热塑性复合材料的界面研究现状

综述了目前国内外关于木纤维增强热塑性复合材料界面的研究进展，介绍了常用的几种改善木塑复合材料界面相容性的方法，并分析了各自的优缺点。     

木纤维增强聚丙烯复合材料性能的研究

与常用的对木纤维进行化学改性的方法相比，本研究采用磺酰胺类增塑剂，在高速捏合机上对木纤维增塑，从而改进木纤维在聚丙烯中的分散性，采用马来酸酐接枝聚丙烯作为相容剂，使用了四种不同形态的木纤维来增强聚丙烯，研究了复合材料的力学性能与纤维种类、含量的关系，通过SEM研究了复合材料的断面形态，通过熔体流动速率研究了复合材料加工性能等。     

Effect of Coupling Agent Concentration,Fiber Content,and Size on Mechanical Properties of Wood/HDPE Composites

In this study, the influence of coupling agent concentration (0 and 3 wt%), wood fiber content (50, 60, 70, and 80 wt%), and size (40–60, 80–100, and 160–180 mesh) on the mechanical properties of wood/high-density-polyethylene (HDPE) composites (WPCs) was investigated. WPC samples were prepared with poplar wood-flour, HDPE, and polyethylene maleic anhydride copolymer (MAPE) as coupling agent. It was found that the tensile properties and the flexural properties of the composites were improved by the addition of 3 wt% MAPE, and the improved interfacial adhesion was well confirmed by SEM micrographs. It was also observed that the best mechanical properties of wood/HDPE composites can be reached with larger particle size in the range studied, while too-small particle size was adverse for the mechanical properties of wood/HDPE composites. Moreover, the tensile modulus, tensile strength, and flexural strength of WPCs decreased with the increase in fiber content from 50 to 80 wt%; the flexural modulus of WPCs increased with the increase in fiber content from 50 to 70 wt% and then decreased as the fiber content reached 80 wt%. The variances in property performance are helpful for the end-user to choose an appropriate coupling agent (MAPE) concentration, wood fiber content, and particle size based on performance needs and cost considerations.     

Effect of Wood Fibers on the Rheological and Mechanical Properties of Polystyrene/Wood Composites

The effects of wood fibers on the rheological and mechanical properties of polystyrene/wood (PS/wood) composites were investigated. The composites with different ratios of PS and wood were prepared by means of internal mixer and, additionally, two different sizes of the wood particles were used, such as ～100 and ～600 µm. The rheological properties were studied using capillary rheometer, apparent shear rate, apparent shear stress, apparent viscosity, power law index, and flow activation energy at a constant shear stress were determined. The rheological results showed that the shear stress–shear rate variations obeyed a power law equation, and the composites exhibited shear thinning. The flow activation energy of the composites increased with the addition of wood particles. Mechanical results showed that stress at break of the composites was higher than that of pure PS, whereas the strain at break and impact strength of the composites were lower than that of PS. In addition, the mechanical properties of the present composites were improved when the small size of wood particles were incorporated.     

Effect of fiber treatment on the mechanical properties of hybrid fiber reinforced polystyrene composites. Part II. Use of glass fiber and wood pulp as hybrid fiber

The mechanical properties of polystyrene reinforced with a mixture of hardwood aspen chemithermomechanical pulp (CTMP) and surface-treated glass fiber have been studied. The adhesion of cellulose fiber to glass fiber as well as to thermoplastics improved thanks to various surface treatments of CTMP, e.g. coating with polymer+isocyanate or with silane, and grafting with polystyrene. In general, compared with non-treated CTMP-filled composites, the mechanical properties improved when surface-treated wood fiber was used as a filler. Experimental results indicate better compatibility between treated wood fiber and surface-treated glass fiber as well as polystyrene and, consequently, the mechanical properties were enhanced.     

玻璃纤维/嵌段共聚聚酰亚胺复合材料力学性能的研究

采用热塑性聚酰亚胺膜熔渗法,制备了单向玻璃纤维/嵌段共聚聚酰亚胺膜层压复合材料,考察了嵌段共聚聚酰亚胺的理论分子量、嵌段比(由BPDA段含量表示)对复合材料力学性能的影响。结果表明,分子量和嵌段比能显著影响嵌段共聚聚酰亚胺的分子链柔性,复合材料的弯曲强度、弯曲模量、层间剪切强度和冲击强度均随理论分子量的增大或刚性段含量的增加呈现出先增加后降低的趋势,最大弯曲强度、最大弯曲模量、最大层间剪切强度和最大冲击强度分别达到1224.52MPa、31.82GPa、70.56MPa和447.55kJ/m2。     

不同相容剂对PP/木粉复合材料力学性能的影响

研究了3种相容剂和3种偶联剂分别在单独使用和配合使用情况下对PP/木粉(质量比50/50)复合材料力学性能的影响。相容剂PP-g-MAH、PE-g-MAH、SBS-g-MAH单独使用发现:SBS-g-MAH使材料综合性能最好,PE-g-MAH对冲击强度提高明显。硅烷偶联剂HP-172在提高复合材料的冲击强度和拉伸强度方面较好,HP-174对弯曲性能改善较好,钛酸酯偶联剂NDZ-201仅对弯曲模量有所改善,而对其它性能改善不大。相容剂与偶联剂共同使用具有协同效应,其中HP-174与SBS-g-MAH并用效果最好,使各项力学性能都有提高。     

玻璃纤维增强PPBES基复合材料性能

以共聚型二氮杂萘联苯结构聚醚砜(PPBES)树脂为基体,连续玻璃纤维(GF)为增强体,通过溶液预浸,热压成型工艺制备单向复合材料。通过对树脂溶液黏度、复合材料纤维体积含量测试,并对复合材料样条进行三点弯曲、层间剪切试验,研究了纤维体积含量对复合材料力学性能的影响,借助断面形貌分析了复合材料受力破坏模式。结果表明,PPBES/GF复合材料的弯曲强度随纤维体积含量的增加呈现先增大后减小的趋势,极值出现在纤维体积含量为57%时,弯曲弹性模量和层间剪切强度随纤维体积含量的增加呈现逐渐增大的趋势,复合材料的受力破坏模式为界面脱粘破坏和树脂基体内部破坏同时存在。     

Assessment of Glass/Drumstick Fruit Fiber (Moringa oleifera) Reinforced Epoxy Hybrid Composites

Glass fibers/drumstick fruit fibers (GF/DFF) reinforced with epoxy hybrid composites were fabricated using the rule of hybrid mixtures. Properties like impact strength, frictional coefficient, dielectric strength, and chemical resistance were studied. Treated and untreated DFF were reinforced along with GF to assess two different epoxy hybrid composites. The effect of alkali treatment on the above-mentioned properties was also studied. It is observed that the impact strength and frictional coefficient properties of the hybrid composites increased with increase in glass fiber content. Performance was elevated for alkali-treated DFF hybrid composites when compared with untreated DFF. Chemical resistance was significantly increased for all chemicals except carbon tetrachloride due to attack of chloride hydrocarbons on the cross-linking of the epoxy. Elimination of amorphous hemi-cellulose by alkali treatment improved the properties. Fiber-polymer interactions were studied by scanning electron microscopy on the cross-sections of fractured surfaces.     

界面强度对玻璃纤维增强不饱和聚酯复合材料静态和动态力学性能影响

采用3种高强高模玻璃纤维与不饱和树脂,分别制备了3种单向板复合材料和3种织物复合材料,通过纤维束拔出法和韦布分析法表征了3种玻璃纤维与不饱和树脂间的界面结合强度,并研究了界面强度与复合材料静态和动态力学性能。结果表明:3种纤维的本征界面强度分别为27.12,34.91,35.60MPa;界面强度对复合材料静态力学与疲劳性能有着重要的影响,但对模量的影响较小。随着界面强度的增加,90°方向的拉伸强度逐渐增加,但是0°方向上的拉伸强度反而下降。当疲劳应变较低时,界面强度的增加有助于疲劳性能的提高;但当疲劳应变提高时,界面强度对疲劳性能的影响降低,与材料初始强度反而有着明显的相关性。     

连续玄武岩纤维增强复合材料力学性能试验研究

连续玄武岩纤维(CBF)由于其优异的力学性能、物理性能和较低的价格,在土木工程中应用前景广泛。CBF可以与树脂复合制作片状、板状、筋状等各种各样的复合材料(CBFRP),在实际工程中科学合理应用CBFRP,必须对其力学性能作深入了解。对CBFRP片材和棒材的力学性能进行研究,重点讨论了影响CBFRP力学性能的各种参数,研究结果可为CBF及其CBF片材生产厂家提供参考,并为CBF的深入研究和工程应用打下基础。     

织物处理工艺对苎麻纤维增强复合材料力学性能的影响

选取了几种不同处理工艺制作的苎麻织物,分别对比其化学组成、单丝拉伸性能,以及对比苎麻纤维增强复合材料的力学性能,最终找到最佳的增强材料用苎麻纤维织物的处理方法。结果表明:苎麻纤维被处理的越细,对纤维的力学性能损伤就越大;省去去毛以及漂白工艺,可以使复合材料力学性能有一定程度的提高;生物酶脱胶处理工艺对环境影响更小,而且与化学脱胶相比,纤维的力学性能和复合材料的力学性能基本持平。     

Improving adhesion of wood fiber with polystyrene by the chemical treatment of fiber with a coupling agent and the influence on the mechanical properties of composites

—The mechanical properties of polystyrene filled with chemithermomechanical pulp and wood residues of softwood and hardwood species, which were precoated with phthalic anhydride and various polymers, e.g. polystyrene and PVC, have been investigated. The extent of improvement in the mechanical properties of the composite materials depends on the coating composition, the concentration of phthalic anhydride, the nature of the coated polymers, as well as the concentration of fiber, the nature of the wood species, and the nature of the pulps. Experimental results indicate that phthalic anhydride acts as a coupling agent, but when its performance was compared to that of poly[methylene (polyphenyl isocynate)], it seemed inferior to the latter.     

纤维类型对C/SiC复合材料性能的影响

利用化学气相浸渗法制备了Cf-C/SiC复合材料,借助SEM、TEM等研究了纤维类型对Cf-C/SiC复合材料力学性能的影响.实验证明T300碳纤维增韧补强效果优于M40碳纤维,利用T300碳纤维制备出弯曲强度为459M,断裂韧性为20.0MPa*m1/2,断裂功为25170J/m2的Cf-C/SiC复合材料.2种碳纤维增韧效果的差异是由纤维的原始强度、热膨胀系数和弹性常数的不同决定的.     

Kevlar、PBO有机纤维及其复合材料的性能

简述Kevlar纤维和PBO纤维的合成、结构、优异性能及应用前景。实验表明：在同等强度下，PBO纤维／环氧复合材料在高性能纤维复合材料中减重效果最好。     

HDPE-g-MAH增容HDPE/木粉复合材料的制备及加工设备的研究

使用HDPE-g-MAH做增容剂,通过双螺杆挤出机制备了HDPE/木粉复合材料,对HDPE-g-MAH进行量变实验,通过力学性能测试确定了最佳用量,并利用SEM对材料微观形貌进行了观察。在此基础上又采用单螺杆挤出机、开炼机和密炼机等不同的加工设备分别制备了木塑复合材料,对力学性能进行了对比表征。结果表明:HDPE-g-MAH的加入很好地改善了木塑复合材料的界面相容性、力学性能和木粉的分散性,HDPE-g-MAH的最佳用量为5份;而且只有使用剪切效果优良的双螺杆挤出机才能制备出性能优异的木塑复合材料。     

影响聚丙烯基木塑复合材料力学性能因素

研究了偶联剂、相容剂、木粉用量和木质填料种类对以聚丙烯（PP）为基体树脂制备小塑复合材料力学性能的影响。结果表明，以硅烷偶联剂处理木粉或直接加入相容剂均使复合材料力学性能得到提高；木粉用量的提高使复合材料冲击强度下降，弯曲强度、弯曲模量、拉伸强度则大幅提高；在分别以粒径为0．14mm木粉和0．22mm木粉、竹粉、花生壳粉、稻壳粉制备复合材料，以粒径为0．14mm木粉与PP制备的复合材料力学性能最好。     

Influence of Coupling Agents on Melt Flow Behavior of Natural Fiber Composites

The influence of coupling agents on the melt rheological properties of natural fiber composites has been investigated in this work using capillary and rotational rheometers. Scanning electron microscopy was also employed to supplement the rheological data. It was found that molecular weight and molecular weight distribution of the polymer matrix and coupling agent characteristics influence the filler wetting and the melt flow properties of the filled composites. Generally, low molecular weight and narrow molecular weight distribution polyethylene matrix provides relatively larger increase of the viscosity of the composites. Coupling agents tend to increase the resistance to shearing, but wall slip effects may interfere with the measured values, especially at very high filler loadings. Entrance pressure loss in capillaries is also influenced by polymer matrix and coupling agent used.

     

玻纤对湿热环境下的环氧复合材料拉伸性能的影响

为了研究湿热环境下玻璃纤维对环氧复合材料拉伸性能的影响,建立试验模型,以不同浸润剂配方生产的相同单丝直径及TEX值的玻璃纤维进行浸胶制样,样条在95℃下1%浓度的NaCl溶液中浸泡24 h、72 h后,样条拉伸强度变化,从而得出玻璃纤维对在湿热环境下环氧复合材料拉伸性能的影响,即选用合适的偶联剂生产的玻璃纤维,对复合材料湿态拉伸强度有明显的提升。     

不同玻璃纤维类型机织物增强的复合材料 性能分析

通过将普通E玻璃纤维,高性能玻璃纤维(HT)和低介电玻璃纤维(HL)织造成机织物,再通过真空灌注的方法,制备成玻璃纤维复合材料。分别从纤维增强体,树脂和界面三方面分析了性能差别的原因。结论证明复合材料是通过界面进行应力传递,但主要是依靠主体材料,主体材料性能高,其相对应的复合材料性能也会高。高性能玻璃纤维可以应用于军工、航空等高强度要求的领域,而低介电玻璃纤维则应用于电子通信领域,满足介电常数低的要求。总之,通过数据说明,针对不同的市场应用领域,选用不同的差异化产品。