长玻璃纤维增强PP/m-PA6复合材料的制备及性能研究

采用熔融拉挤工艺技术制备了长玻璃纤维增强聚丙烯/聚酰胺6[LFT- (PP/m-PA6)]粒料,并研究了材料的界面相互作用情况、力学性能和流变性能。结果表明, m-PA6改善了PP树脂与玻纤之间的润湿性和浸淆性, 提高了界面粘接强度, 使LFT-(PP/m-PA6)的拉伸强度和弯曲强度增加、刚性增强、韧性基本不变; 当长玻纤含量相同时, 以均聚PP（F401）为基质的长玻纤增强聚丙烯（LFT-PP）和LFT-(PP/m-PA6)的力学性能高于以共聚PP（K712）为基质的LFT-PP和LFT-(PP/m-PA6),特别是缺口冲击强度明显提高;在-30 ℃下,LFT-PP（F401）的缺口冲击强度提高了3.91 %,LFT-PP（K712）的缺口冲击强度提高了7.53 %; m-PA6起到了界面润滑作用, 能使LFT-(PP/m-PA6)的流动性能更好。     

长玻璃纤维增强聚丙烯复合材料的力学性能

采用自主开发的在线混合生产设备,以玻璃纤维(GF)和聚丙烯(PP)为原料,制备了长玻璃纤维增强聚丙烯(LFT-PP)复合材料。研究了GF长度、分散度以及界面改性剂对LFT-PP力学性能的影响。结果表明,GF长度的增加,有利于提高LFT-PP的弯曲强度和冲击强度,对弯曲模量的影响很小。添加适量的界面改性剂有利于提高复合材料的弯曲性能,但是降低了其冲击强度。     

PP-g-MAH对玻璃纤维增强PP的影响

研究了聚丙烯接枝马来酸酐(PP-g-MAH)和剪切场强度等对玻璃纤维增强聚丙烯(GFRPP)性能的影响。加入PP-g-MAH后,GFRPP的拉伸强度持续增加,最大达82.5 MPa;弯曲性能大幅度提高;缺口冲击强度明显增大,最大达160.3 J/m;热变形温度基本维持不变。PP-g-MAH的加入可改善玻璃纤维与聚丙烯间的界面作用,从而有利于提高GFRPP的性能。在极高剪切场强度的条件下,GFRPP的力学性能和热性能有所下降。     

再生家电壳体聚丙烯材料性能改善研究

再生家电壳体聚丙烯材料通过玻璃纤维增强改性可以显著提升材料的拉伸强度及弯曲模量,但由于再生聚丙烯材料中杂质的影响,材料的缺口冲击强度没有获得明显提升。从改善再生家电壳体聚丙烯材料性能的角度出发,通过掺入再生聚丙烯、添加弹性体和改变玻璃纤维直径等研究了改性材料的性能差异。在全新聚丙烯与再生聚丙烯共混体系中,随着再生聚丙烯含量增加,改性材料的弯曲模量无明显变化,但缺口冲击强度急剧下降。当再生聚丙烯添加质量分数大于30%时,改性材料的缺口冲击强度下降35%。在玻璃纤维增强再生聚丙烯体系中,通过添加质量分数为5%的弹性体,可以显著改善改性材料的缺口冲击强度,同时保持良好的拉伸强度与弯曲模量;使用小直径玻璃纤维可以明显改善改性材料的缺口冲击强度,当玻璃纤维直径由14μm降低至10μm时,缺口冲击强度由8 kJ/m²提升至11 kJ/m²。     

基体树脂对长玻璃纤维增强PP力学性能的影响

采用在线混合设备制备了长玻璃纤维(LGF)增强聚丙烯(PP)复合材料(LGF-PP),研究了基体性质及界面相容剂对LGF-PP力学性能的影响。基体树脂熔体流动速率的增加,使最终LGF-PP中的玻璃纤维长度从5.63 mm增至8.56 mm,提高了力学性能。与均聚PP比较,以共聚PP为基体树脂的LGF-PP冲击强度高出约10%,但其他性能略差。界面相容剂有利于增强玻璃纤维与PP的界面结合,拉伸强度和拉伸模量明显增加,但是冲击强度降低了20%～30%。     

注射压缩成型工艺对长玻璃纤维增强聚丙烯注塑制品力学性能的影响

以长玻璃纤维增强聚丙烯(LFT-PP)为材料,利用自行设计带有压缩功能的模具,基于单因素实验方法,研究了压缩距离、压缩速度和压缩力对注射压缩成型(ICM)试样的玻璃纤维残余长度和力学性能的影响规律,在此基础上,对比了常规注塑成型(IM)和ICM方法成型的LFT-PP的玻璃纤维残余长度和力学性能差异。结果表明,玻璃纤维残余长度是引起ICM试样力学性能变化的主要因素,随着压缩距离、压缩速度以及压缩力的增大,试样内的纤维残余长度均先增加后减少,力学性能也随之先上升后下降;与拉伸强度相比,工艺参数对缺口冲击强度的影响更为明显。与IM相比,ICM可减少充模过程中纤维的断裂程度,提高玻璃纤维增强效率,增加制品的力学性能。ICM样品的平均玻璃纤维长度增加了44.1%,拉伸强度增加了18.4%,缺口冲击强度增加了243%。     

GF增强PP复合材料的尺寸稳定性与力学性能

研究了马来酸酐接枝聚丙烯(PP-g-MAH)含量及玻璃纤维(GF)含量对GF增强聚丙烯(PP)复合材料尺寸稳定性与力学性能的影响。结果表明,加入PP-g-MAH后,复合材料的线性膨胀系数和收缩率下降,结晶度、拉伸强度、弯曲强度和悬臂梁缺口冲击强度提高,但断裂伸长率下降。相比不添加PP-g-MAH的复合材料,当PP-g-MAH质量分数达到6%时,复合材料在流道方向上的线性膨胀系数从29.88μm/(m·℃)降低至24.93μm/(m·℃),在流道方向上的收缩率从0.20%下降至0.18%,拉伸强度、弯曲强度和悬臂梁缺口冲击强度基本达到最大值,分别提高130.18%,96.52%和49.20%;随着GF质量分数的增加,复合材料的线性膨胀系数和收缩率均显著下降,拉伸强度、弯曲强度和悬臂梁缺口冲击强度提高,而断裂伸长率和结晶度下降。相比不添加GF的复合材料,当GF质量分数为40%时,复合材料在流道方向上的线性膨胀系数从101.30μm/(m·℃)降低至18.08μm/(m·℃),在流道方向上的收缩率从1.43%下降至0.08%,结晶度从45.05%下降至23.96%,拉伸强度、弯曲强度和悬臂梁缺口冲击强度分别提高168.87%,306.40%和129.52%。     

短切碳纤维增强聚丙烯复合材料的性能

研究了短切碳纤维用量、相容剂用量以及短切玻璃纤维/短切碳纤维二元混杂纤维对增强聚丙烯复合材料力学性能的影响,并采用扫描电子显微镜观察了复合材料的表面形貌。结果表明:随着相容剂用量的增加,复合材料的拉伸强度和弯曲强度先增加后降低,悬臂梁缺口冲击强度和弯曲模量先增加后降低,而且极大提升了树脂和纤维的界面结合力;短切玻璃纤维较短切碳纤维在复合材料中的保留长度大,与纤维的保留长度相比,纤维的体积分数对熔体流动速率的影响更大。     

材料的形式对GF增强PPS冲击强度的影响

采用不同长度及不同形式的玻璃纤维(GF)增强聚苯硫醚(PPS),研究了纤维的长度及形式对PPS/GF复合材料冲击性能的影响.结果表明,注塑成型的短GF增强PPS(纤维长度小于0.8 mm)其冲击强度为14.4 kJ/m2,随着注塑样品中纤维长度的增加,其冲击强度可达到23.0 kJ/m2;采用悬浮分散使纤维与树脂混合并经模压成型的样品其缺口悬臂梁冲击强度可达29.0 kJ/m2;利用粉末浸渍工艺制备的连续玻璃纤维预浸料编织物与悬浮分散体系叠层模压成型的板材,冲击强度可达137.40 kJ/2.     

PP-g-GMA对长玻纤增强聚丙烯复合材料性能的影响

采用熔体浸渍工艺制备了长玻纤(LGF)增强聚丙烯材料。研究了甲基丙烯酸缩水甘油酯接枝聚丙烯(PP-g-GMA)对长玻璃纤维增强聚丙烯(PP)复合材料力学性能的影响。结果表明:PP-g-GMA影响长玻璃纤维增强PP复合材料的力学性能;当PP-g-GMA质量分数为1%时,PP/LGF复合材料的力学性能最好,拉伸强度、弯曲强度和悬臂梁缺口冲击强度分别提高32.34%、27.38%和74.51%。     

短玻纤增强聚丙烯的研究进展

综述了近年来有关短玻纤增强聚丙烯复合材料的力学性能、变形机理和断裂韧性等方面的研究工作。短玻纤取向后的复合材料注射样的力学性能是各向异性的 ,复合材料在取向方向上具有更高的拉伸强度。玻纤与树脂基体间界面结合力的强弱对材料的力学性能同样起着至关重要的作用。良好的界面结合力保证了应力有效地从基体向玻纤传递 ,从而提高了复合材料的强度。由于短玻纤的分布既不均匀又不规则 ,在受到负荷时的变形过程很复杂 ,包括玻纤 -基体的界面脱黏、脱黏后的摩擦、基体的塑性变形、玻纤的塑性变形、玻纤断裂、基体断裂和玻纤抽出等     

Characterization of the fracture behavior of glass fiber reinforced thermoplastics based on PP,PE‐HD,and PB‐1

This article deals with the influence of the polymeric matrix, such as isotactic polypropylene (iPP), polyethylene (PE‐HD), and isotactic polybutene‐1 (iPB‐1), and the glass fiber content on the material behavior of short glass fiber reinforced thermoplastics. The glass fiber content of all materials ranged between 0 and 50 wt %, which corresponds to a volume content between 0 and approx. 0.264. To describe the mechanical properties of all materials, the stiffness, strength, hardness, and toughness behavior were determined. The crack toughness behavior regarding unstable crack propagation was also assessed by applying fracture mechanics concepts. It was found that the energy‐determined J‐values for the PP material system reach their maximum at a glass fiber content of 0.135. In contrast, the crack toughness of the PE‐HD materials increases continuously with increasing glass fiber content due to the unchanged deformation ability at simultaneously increasing strength. The toughness level of the PB‐1 materials is nearly the same independent of the glass fiber content due to the opposite trend of the load and the deformation ability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Improvement in impact property of continuous glass mat reinforced polypropylene composites

The toughened polypropylene (PP) was obtained by the blending of PP with ethylene‐propylene diene monomer (EPDM). The impact property of continuous glass mat‐reinforced polypropylene was adjusted through three ways: different toughness PPs and their blends were used as matrices, the functionalized polypropylene was added into the matrix to control the interfacial adhesion; the ductile interlayer was introduced at the fiber/matrix interphase by the grafting and crosslinking of rubber chains on fiber surface. The effect of PP toughness, interfacial adhesion, and ductile interlayer on the mechanical properties of composite systems was studied. The impact toughness of GMT increased with increasing the matrix toughness, whereas the flexural strength and modulus decreased. The good interfacial adhesion resulted in the low impact toughness. However, GMT composite with high strength, modulus, and impact toughness could be obtained by the introduction of a ductile interlayer at fiber/matrix interphase. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2680–2688, 2002     

PA6/GF/SP三元复合材料的制备及其力学性能研究

以矿渣微粉（SP）和玻璃纤维（GF）为填料,经共混、挤出造粒、注射成型工序制备聚已内酰胺（PA6）/GF/SP三元复合材料,采用扫描电子显微镜观察断口形貌,通过检测复合材料试样的拉伸强度、冲击强度研究不同GF/SP配比比例以及SP的粒径对复合材料的力学性能影响。结果表明,当GF/SP配比填料总量定为30 %（质量分数,下同）,SP与GF比例为1∶3时,平均粒径为7 μm的SP有最好的增强效果,拉伸强度为96.8 MPa;当SP平均粒径为15 μm时,三元复合材料具有最佳的冲击强度,比纯PA6提高了32.4 %,达到8.31 kJ/m2。     

Crack-Wake Debonding and Toughness in Fiber- or Whisker-Reinforced Brittle-Matrix Composites

Solutions are obtained for the mechanics of debonding in the crack wake in fiber- or whisker-reinforced composites for the case where a finite shear traction exists at the fiber/matrix interface in the debonded zone. These solutions are then applied to derive expressions for the steady-state toughness increases obtained in bonded composites wherein the toughness contribution is provided by crack-wake fiber/matrix debonding and crack bridging. The solutions for an unbonded composite containing a frictional fiber/matrix interface can be obtained from the derived equations in the limit of the fiber/matrix interface toughness equal to zero. In this limit, the debond crack length reduces to the slip length and the expressions for the crack opening and the predicted toughness increase reduce to previously derived expressions for unbonded composites. The steady-state toughness is found to depend sensitively on the interface toughness, the fiber fracture strength, and the shear tractions in the debonded zone including other material parameters, such as fiber radius and volume fraction and the moduli of the constituent phases. It is shown that in order to obtain finite toughness increases, the fiber/matrix interface toughness must be less than a critical value dependent on the fiber fracture strength, fiber radius and volume fraction, and fiber and matrix moduli. The predictions of the model are applied to published experimental results from a detailed and complete study of toughness increases in a bonded whisker-reinforced composite.     

Essential work of fracture (EWF) analysis for short glass fiber reinforced and rubber toughened nylon‐6

The effect of fiber content on the fracture toughness of short glass fiber reinforced and rubber toughened nylon‐6 has been investigated using the essential work of fracture (EWF) analysis under both quasi‐static and impact rates of loading. Under quasi‐static loading rate, matrix plastic deformation played a major role. Addition of 10 wt% of short glass fibers into a rubber toughened nylon‐6 matrix improved the fracture toughness substantially. This is due to the synergistic effect that comes from matrix yielding and fiber related energy absorption such as fiber debonding, fiber pull‐out and fiber fracture. With further increasing the glass fiber content, up to 20 and 30 wt%, even though plastic deformation could still take place on the fracture surfaces, the depth of the fracture process zones was much smaller when compared with the system with 10 wt% of glass fibers. The reduction in fracture process zone caused the reduction in fracture toughness. Under impact loading rate, the unreinforced blend still fractured in a ductile manner with gross yielding in the inner fracture process zone and the outer plastic zone. The unrein‐forced blend therefore possesseed higher fracture toughness. For the fiber reinforced blends, the matrix fractured in brittle manner and so fracture toughness of the reinforced blends decreased dramatically. The impact fracture toughness increased slightly after incorporation of a higher weight percentage of glass fibers.     

塑钢纤维磷渣混凝土弯曲性能研究

以不掺塑钢纤维的磷渣混凝土为基准,对纤维长度为30 mm、40 mm、55 mm和纤维掺量为3 kg/m³、6 kg/m³、9 kg/m³的塑钢纤维磷渣混凝土进行四点弯曲试验,研究不同纤维长度和纤维掺量对磷渣混凝土弯曲性能的影响规律。研究结果表明:随着塑钢纤维长度和掺量的增加,磷渣混凝土的抗弯强度随之增加,塑钢纤维长度为55 mm,掺量为3 kg/m³时,对磷渣混凝土抗弯强度增强效果最佳,抗弯强度比基准组提高了56%;随着塑钢纤维长度和掺量的增加,磷渣混凝土弯曲韧性指数不断增大,弯曲韧性不断提高,塑钢纤维长度为55 mm,掺量为9 kg/m³时,弯曲韧性指数I₂₀比基准组提高了9.8倍。     

玻纤表面处理对于玻纤增强PET复合材料断裂韧性的影响

本文以三组分别经脱蜡处理、涂层处理及未经任何处理的玻纤为增强纤维，ＰＥＴ为基体纤维，采用混纤纱浸渍技术，制备连续玻纤增强混纤纱复合材料单向板。通过对所制备材料力学性能的对比，研究了玻纤表面处理对玻纤增强ＰＥＴ复合材料断裂韧性的影响。     

长玻纤增强聚丙烯热塑性复合材料制备风光互补发电系统风能叶片的模具设计和注射成型

对长玻纤增强聚丙烯(LFT-PP)和短玻纤增强聚酰胺(SFT-PA6)的性能进行了测试与比较。常温时(23 ℃),悬臂梁缺口冲击强度前者比后者提高3.44 %,吸水率后者比前者高100 %,模收缩率前者比后者低10 %;低温时(-30 ℃),前者的冲击强度提高了16 %~24 %。通过优化的模具设计、模流数值计算分析和注塑工艺条件实验,选择最佳注塑工艺参数制备LFT-PP叶片,可使叶片疲劳断裂强度的最大静载荷测试值达到150 kg。     

Mechanical and high velocity impact performance of a hybrid long carbon/glass fiber/polypropylene thermoplastic composite

This research explores mechanical and high velocity impact response of hybrid long carbon/glass fiber-reinforced polypropylene thermoplastic composites (HLFT) with different fiber lengths. The work examines three hybrid long fiber thermoplastic composites, i.e., 5, 10 and 20 mm. The HLFTs were prepared by a combination of extrusion and pultrusion processes and using a cross-head die. Tensile and Izod impact tests were carried out to evaluate the mechanical performance of each HLFT compound. A gas gun with a spherical projectile was used to conduct high velocity impact tests at three velocities of 144, 205 and 240 m/s. The results showed that internal mixing operation caused extensive reduction in fiber length of all three LFT lengths. Tensile strength, modulus and Izod impact test results were the indications of higher values with increase in HLFT length. Comparison of these results for the HLFT with that of corresponding glass/PP LFTs, adopted from earlier work by Shayan Asenjan et al. (J Compos Mater 53:353–360, 2019), showed better performance of HLFT. The high velocity impact results showed a steady higher impact performance with the increase in HFLT fiber length for all impact velocities tested. Comparison of HLFT high velocity impact performance revealed better results for all impact velocities tested with that of the corresponding glass/PP LFT composite.