制备工艺对亚麻增强聚丙烯复合材料拉伸性能的影响

以亚麻纤维为增强体,与聚丙烯（PP）长丝进行丝束级共混,形成PP包覆亚麻的纱线结构,利用机织工艺织成二维机织布,作为复合材料的预制件。采用层合热压方法制备PP／亚麻复合材料板材。通过对板材拉伸性能测试及扫描电镜（SEM）拉伸断口形貌分析,研究了不同纤维体积分数、织造密度及织造组织等因素对复合材料拉伸性能的影响。结果表明,在选取最优热压温度与压力的条件下,纤维体积分数为50％的板材性能最优;经向密度相同时,拉伸性能随着纬向密度的增加而提高;经、纬向密度均相同时,斜纹3／1组织的板材性能最优,纬向最大拉伸强度可达92．42 MPa。     

亚麻/PP复合材料的制备及其弯曲性能研究

将亚麻纤维作为增强体,与聚丙烯(PP)纤维进行混合,同时与PP长丝形成PP包覆亚麻的纱线结构,利用机织工艺织造成机织布作为复合板材的预制件,采用层合热压方法制备亚麻/PP复合材料。通过对板材弯曲性能进行测试,研究了制备工艺、纱线结构以及亚麻纤维含量(质量分数)等因素对复合材料弯曲性能的影响。研究结果表明,"三明治"铺层方法制备的板材较"混纤法"制备的板材体现出更优异的弯曲性能;与加捻纱相比,包覆纱结构板材表现出更优良的弯曲性能;以亚麻/PP包覆纱为增强体的复合材料,当亚麻纤维质量分数为46%时,其弯曲性能最优良。     

亚麻增强热塑性树脂复合材料板材的研究与应用

以亚麻纤维为增强体,与聚丙烯(PP)纤维按一定比例进行混合,然后制备加捻纱及PP长丝包覆的包覆纱,并利用机织工艺织成二维机织布作为复合材料的预制铺层.采用层合热压方法制备PP/亚麻纤维复合材料板材.通过对板材弯曲性能的测试及分析,研究了制备工艺、纱线结构及亚麻纤维含量等因素对复合材料弯曲性能的影响.     

竹纤维增强聚丙烯复合材料的制备及其性能研究

以适当脱胶处理后的竹原纤维与聚丙烯纤维为原料，采用非织造工程的加工方法制作了混合纤维预制件，通过热压成型工艺制备了竹原纤维增强聚丙烯热塑性树脂复合材料。对复合材料的基本力学性能进行了测试与评价，探讨了预制件制作工艺、竹原纤维比例及热压成型工艺对复合材料力学性能的影响。利用扫描电镜（SEM）研究了复合材料拉伸断口的形貌。结果表明：竹原纤维与聚丙烯纤维的质量配比为50／50，模压温度、时间及压力分别为190℃，30min及30MPa时，制得的复合材料力学性能最好，其纵、横向拉伸强度分别为96．6MPa和82．3MPa；纵、横向弯曲强度分别为400．7MPa和367．3MPa。     

亚麻/聚丙烯机织复合材料薄板的制备与研究

本文以聚丙烯长丝作为基体,亚麻纱线为增强体,二者按一定体积含量进行捻合,形成合股纱,采用机织的方法织造亚麻/聚丙烯共织平纹布.选取五层平纹布进行层合热压,制备出亚麻增强聚丙烯(PP)热塑性复合材料薄板.对其拉伸性能进行测试,并分析破坏机理.     

竹原纤维增强复合材料的研究

竹原纤维与低熔点聚酯纤维及聚丙烯纤维的混合纤维集合体加工成非织造物,再经热压成型后,制成竹原纤维增强聚酯、聚丙烯热塑性树脂复合材料板材,并与竹原/亚麻纤维增强聚酯、聚丙烯热塑性树脂复合材料进行性能对比,进一步探讨这种复合材料板材的最佳制作工艺。鉴于这种材料可以被用于汽车和建筑等领域,通过对材料力学性能测试结果的模糊综合评判,选出性能最优的复合材料为竹原纤维/LMPET(40/60),在模压温度、时间、压力分别为165℃,30min和30MPa的条件下,所压制复合材料的纵向拉伸强度为136MPa,横向为87·58MPa;纵向弯曲强度为534MPa,横向为470MPa。     

废弃混纺纤维/聚乳酸复合材料的制备及力学性能研究

以废弃涤/棉(65/35)混纺纤维作为增强材料,聚乳酸颗粒作为基体材料制备复合材料,并且采用正交及单因素试验对其成型工艺进行优化。结果表明:最优成型工艺条件为涤/棉混纺纤维质量分数40%、热压温度180℃、热压压力12 MPa,该条件下的复合材料的拉伸强度和弯曲强度分别是59.56 MPa和48.75 MPa。     

聚丙烯/亚麻纤维复合材料的成型工艺及力学性能研究

选取聚丙烯(PP)纤维为基体材料,亚麻纤维为增强材料。运用正交设计法,探讨了PP/亚麻纤维复合材料的模压成型工艺。研究分析了两种纤维的质量比、模压温度、热压保温时间对复合材料力学性能的影响。结果表明,两种纤维的质量比为50:50、模压温度为180℃、热压保温时间为60min时,PP/亚麻纤维复合材料的力学性能最佳。     

聚丙烯/秸秆复合材料的成型工艺及性能探究

采用化学方法制备了水稻秸秆纤维,并以水稻秸秆纤维为增强体,聚丙烯为基体,运用纺织技术及热压成型技术制备了聚丙烯/秸秆复合板材。结果表明,采用浓度为4%、浴比为1∶20、温度为80℃的NaOH溶液热煮20 min可提取较纯的秸秆纤维;在12.5 MPa、200℃热压30 min条件下,复合板材成型较好;纤维质量分数为45%时,复合材料具有良好的力学性能。     

成型工艺对玄武岩纤维增强PPS夹芯结构材料力学性能影响

夹芯结构材料具备质量轻、刚性高、功能综合型等优点,广泛应用于航天航空、交通运输、功能材料等领域。为研究成型工艺对夹芯结构材料性能的影响,以玄武岩纤维增强聚苯硫醚复合材料、连续玻璃纤维增强聚丙烯单向预浸带为原材料,探究了模压成型工艺中贴合压力、热压温度、热压时间以及芯层材料密度等因素对夹芯结构材料性能的影响。结果表明,模压成型工艺中热压温度和热压时间的最优条件为220℃,15 min;芯层材料的密度减小时,其弯曲性能、冲击强度呈先增大后下降的趋势,弯曲强度和弯曲弹性模量最大为271.53 MPa,18 672.72 MPa,冲击强度最大为119.21 kJ/m2。芯层材料的密度减小时,其弯曲刚度呈上升趋势,最大弯曲刚度可达15 441.16 N·mm。     

Effect of stacking sequence on mechanical properties of hybrid flax/jute fibers reinforced thermoplastic composites

In this study, the hybrid composites were prepared by stacking jute/PP nonwoven and flax/MAPP woven fabrics in defined sequences. Polypropylene (PP) and maleic anhydride grafted polypropylene (MAPP) were used as matrix materials. Jute and flax fibers were treated with alkali solution in order to improve the interface properties of the resultant composites. The mechanical properties of these hybrid composites were analyzed by means of tensile, flexural, and drop‐weight impact tests. The effect of fabric stacking sequence on the mechanical properties of the composites was investigated. The stacking of nonwovens at the top and in alternate layers has resulted in maximum flexural strength, flexural stiffness, and impact force. It was also shown that hybrid composites have improved tensile, flexural, and impact properties in comparison to neat PP matrix. POLYM. COMPOS., 36:2167–2173, 2015. © 2014 Society of Plastics Engineers     

玻璃纤维针织物增强聚丙烯复合材料的拉伸性能

本文通过实验对由GF/PP复合纱制得的玻璃纤维针织物增强聚丙烯复合材料的拉伸性能进行了研究.拉伸应力-应变曲线研究表明,玻璃纤维针织物增强聚丙烯复合材料的拉伸应力-应变曲线与纯聚丙烯的形状相似,且玻璃纤维针织物的加入确实提高了纯聚丙烯的拉伸性能;对断裂面进行的研究表明,研究中的复合材料的纤维/基体界面结合情况良好.     

Use of preimpregnated sisal yarn in woven reinforced polypropylene sheets: Thermoformability and mechanical properties

Thermoplastic composites were made from polypropylene (PP) and long sisal fibers (SF) by using different processing techniques. Four sets of composites specimens were made with a 60/40 (wt/wt) SF/PP ratio: the first set was made by melt‐blending PP and SF and compression molding 2‐mm‐thick flat sheets; a second set was made by melt‐blending PP, SF, and maleic anhydride grafted polypropylene (MA‐g‐PP); the third set was made by compression molding knitted SF yarns, preimpregnated with PP, between PP sheets; the fourth set was also made by compression molding knitted SF yarns, preimpregnated with diluted MA‐g‐PP, between PP sheets. The bidirectional array of fibers, containing 60% of SF well‐impregnated with a small quantity of MA‐g‐PP, increases the flexural modulus by 600%, the tensile modulus by 475%, and the tensile strength by 300% compared with unfilled PP. The composites sheets were successfully thermoformed with small wall thickness reductions to obtain a three‐dimensional (3D) shape with very low forming energy, outstanding mechanical properties, and excellent surface finish. POLYM. ENG. SCI., 45:976–983, 2005. © 2005 Society of Plastics Engineers     

Faser-Matrix-Haftung in Kunststoffverbunden aus thermoplastischer Matrix und Flachs, 2. Die anwendung von funktionalisiertem polypropylen

Adhesion of flax fibres to a polypropylene matrix in flax/PP composites was improved by pretreating the fibres with polypropylenes grafted with maleic anhydride (MAH). Prior to composite preparation, the flax fibres were loaded with the coupling agent. Shear strength and tear strength were improved by 100% and 25%, respectively. They depend on grafting degree and average molar mass of the PP-MAH graft copolymers. Comparable results were achieved by embedding untreated flax fibres in a PP matrix modified with MAH.     

Use of wet‐laid techniques to form flax‐polypropylene nonwovens as base substrates for eco‐friendly composites by using hot‐press molding

The wet‐laid process with flax (base) and polypropylene (binder) fibers has been used to obtain nonwovens for further processing by hot‐press molding. Mechanical characterization of nonwovens has revealed that slight anisotropy is obtained with the wet‐laid process as better tensile strength is obtained in the preferential deposition direction. The thermo‐bonding process provides good cohesion to nonwovens, which is critical for further handling/shaping by hot‐press molding. Flax:PP composites have been processed by stacking eight individual flax:PP nonwoven sheets and applying moderate temperature and pressure. As the amount of binder fiber is relatively low (<30 wt%) if compared with similar systems processed by extrusion and injection molding, it is possible to obtain eco‐friendly composites as the total content on natural fiber (flax) is higher than 70 wt%. Mechanical characterization of hot‐pressed flax:PP composites has revealed high dependency of tensile and flexural strength on the total amount of binder fiber as this component is responsible for flax fiber embedment which is a critical parameter to ensure good fiber–matrix interaction. Combination of wet‐laid techniques with hot‐press molding processes is interesting from both technical and environmental points of view as high natural fiber content composites with balanced properties can be obtained. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers     

机织/针织混合铺层对复合材料力学性能的影响

为使纺织复合材料同时具有机织结构复合材料和针织结构复合材料的综合力学性能,通过混合铺层方式制备机织/针织混合结构复合材料。以芳纶机织平纹织物和针织罗纹织物为增强体,以环氧树脂为基体,调整复合材料中增强体的铺层顺序,利用真空辅助成型技术制备四层层压机织/针织混合结构复合材料。通过对复合材料拉伸性能、弯曲性能和冲击性能的测试,分析混合铺层和铺层顺序对芳纶环氧树脂复合材料力学性能的影响。结果表明,混合铺层和铺层顺序对芳纶环氧树脂复合材料的弯曲强度和冲击强度有较大影响,特别是对罗纹结构复合材料纬向弯曲强度和冲击强度的改善。当采用相同铺层方式,罗纹织物为受力面时,机织/针织混合结构复合材料具有较大弯曲强度和冲击强度。     

Utilization of Recycled Polypropylene for Production of Eco-Composites

Renewable raw materials and recyclable thermoplastic polymers provide attractive eco-friendly quality as well as environmental sustainability to the resulting natural fiber reinforced composites. We studied the possibility of using the recycled polypropylene (PP) for production of composites based on kenaf fibers (KF) and rice hulls (RH) as reinforcements. Polypropylene/rice-hulls (PP/RH/CA) and polypropylene/kenaf (PP/K/CA) composites with 30% fiber (filler) content and appropriate compatibilizing agent (CA)—a maleic anhydride grafted PP (MAPP), have been prepared by two steps procedure: melt mixing and compression molding. Flexural strength and thermal stability of the composites with recycled PP were similar to those with neat PP. The composites reinforced with kenaf fibers have shown better properties than those based on rice hulls. The flexural strength of the composite sample with recycled PP is 51.3 MPa in comparison with 51.1 MPa for the composite with neat PP. Degradation temperatures of neat and composite with recycled PP at residual weight 90% are 344.4°C and 343.5°C, respectively. The results obtained report the possibility of utilization of recycled PP for the production of natural reinforcements based composites with good mechanical characteristics for using as construction building materials in housing systems.     

GF/PP复合纱针织物预型件热压成型的压力对复合材料拉伸强度的影响

本文实验研究了热压成型压力对GF/PP复合纱针织物制成的复合材料拉伸强度的影响.研究结果表明,在实验研究的压力范围内随着压力的增大,成型后的复合材料的拉伸强度呈现出先增大后减小的变化趋势.本文从压力的变化对熔融的树脂基体受到的向纤维束内部及纤维束之间渗透的外界推动力和阻力的影响角度分析讨论了产生该变化趋势的原因.