磷酸酯偶联剂(FX-1)对PP/POE/Talc复合材料性能的影响

通过熔融共混法制备了PP/POE/Talc复合材料,研究了偶联剂磷酸酯(FX-1)不同含量对滑石粉表面性能的影响,得出了偶联剂磷酸酯(FX-1)的最佳质量分数为1%;同时,考察了超细滑石粉经偶联剂磷酸酯(FX-1)改性前后与基体PP界面的粘接情况对PP/POE/Talc复合材料力学性能的影响。     

表面处理芳纶浆粕增强聚丙烯复合材料的结构与性能

以乙烯醋酸乙烯酯(EVA)为载体,采用溶剂法制备芳纶浆粕(PPTA-pulp)胶粒,利用双螺杆熔融挤出共混的方法制备了芳纶浆粕胶粒/聚丙烯(PP)复合材料,研究了氧等离子体处理及氧等离子体处理和聚丙烯接枝马来酸酐(MPP)组合使用对芳纶浆粕增强聚丙烯复合材料力学性能的影响,研究了复合材料的断面形态和动态力学行为.结果表明氧等离子体处理可以在芳纶浆粕表面引入活性基团,从而使纤维与基体之间的界面粘结得到增强,提高了复合材料的力学性能、动态储存模量和PP的玻璃化转变峰温度,添加MPP后,复合材料的力学性能得到更进一步改善.     

芳纶浆粕增强聚丙烯复合材料的结构与性能

利用双螺杆挤出机制备了聚丙烯(PP) /芳纶浆粕(PPTA-pulp)以及聚丙烯(PP)/芳纶浆粕(PPTA-pulp)/马来酸酐接枝聚丙烯(MAH-g-PP)复合材料。采用力学性能测试、差示扫描量热仪（DSC）、扫描电子显微镜(SEM)、平板流变仪,研究了PP/ PPTA-pulp复合材料的力学性能、结晶行为、断面形态结构及流变行为。结果表明：随着PPTA-pulp含量的增加,复合材料的拉伸强度和弯曲模量增加,缺口冲击强度和断裂伸长率下降,芳纶浆粕对聚丙烯结晶起了成核剂的作用。马来酸酐接枝聚丙烯(MAH-g-PP)作为相容剂,改善了PPTA-pulp与基体PP分子之间的亲和性,提高了界面作用力,并使复合材料的储存模量、损耗模量和力学性能进一步改善。     

椰壳纤维/PBS可降解复合材料的研究

采用碱溶液和偶联剂对椰壳纤维进行表面处理,用转矩流变仪的密炼装置,制备未进行表面处理的不同纤维含量的椰壳纤维/PBS(聚丁二酸丁二醇酯)复合材料和经表面处理的不同纤维含量的椰壳纤维/PBS复合材料。重点研究了椰壳纤维和偶联剂含量对复合材料力学性能的影响。结果表明,椰壳纤维含量和偶联剂含量对复合材料的力学性能影响最大。当椰壳纤维含量为45%时,复合材料的力学性能最好,其拉伸强度、弯曲强度和冲击强度分别为38.59 MPa、52.43 MPa、10.45 k J/m2;偶联剂含量对冲击强度影响不大,但氢氧化钠浓度对冲击强度有一定影响。随着椰壳纤维含量的增加,材料的力学性能相应提高;偶联剂含量增加,纤维-树脂的界面黏结性能提高,材料的力学性能随之提高。扫描电子显微镜(SEM)图片显示,碱处理和偶联剂很好地改善了纤维-树脂的界面黏结性能。     

短芳纶纤维增强聚苯硫醚复合材料的性能

研究了短芳纶纤维增强ＰＰＳ／ＰＥＫ－Ｃ复合材料树脂体系的力学性能。主要讨论了短芳纶纤维的长度、含量及芳纶纤维的表面处理方法和压制温度对复合材料体系力学性能的影响。结果表明：纤维的长度和含量对力学性能有显著影响,在相同纤维含量下,纤维长度增加可使纤维末端数减少,减少了应力集中点,有利于拉伸强度和冲击强度的提高。芳纶纤维不需经过表面化学处理即与ＰＰＳ有良好的界面特性。随加工温度升高,复合材料冲击强度降低,拉伸强度提高     

正辛醇接枝改性杉木粉的制备及其对PP/杉木粉复合材料性能的影响

以甲苯二异氰酸酯(TDI)为偶联剂将正辛醇接枝到杉木粉表面,同时考察处理前后杉木粉填充PP复合材料的力学性能。通过红外光谱分析(FTIR),扫描电子显微镜分析(SEM)等方法对材料的结构进行了分析。结果表明:与未接枝改性杉木粉相比接枝改性杉木粉/PP复合材料的力学性能显著提高,其拉伸强度和冲击强度可分别提高44.3%和65.0%。扫描电镜照片显示正辛醇接枝改性杉木粉在基体中分散更均匀。     

农业废弃秸秆纤维填充聚氯乙烯复合材料相容性的实验探究

采用NaOH溶液浸泡、乙酸酐处理、添加硅烷偶联剂KH570和微波辐照的方法对玉米秸秆纤维进行表面处理,探讨不同实验条件下界面的相容性对复合材料力学性能、热稳定性和防水性能的影响。结果表明:碱溶液蚀刻和微波辐照均可以有效降低秸秆纤维的表面极性,并提高纤维在PVC内部的分散性,从而达到增强界面相容性的效果。与碱溶液蚀刻相比,微波辐照改性的复合材料的力学性能、热稳定性能和防水性能均显著提升。硅烷偶联剂KH570和乙酰化处理可以分别在秸秆纤维表面接枝羧基和乙酰基,从而增强复合材料的相容性。同时,由于乙酸酐力学性能较差,偶联剂对复合材料的性能提升效果优于乙酰化的效果。因此,偶联剂的接枝更适用于优化植物纤维填充PVC复合材料的相容性和性能。综合实验结果,通过微波辐照和偶联剂接枝处理提升秸秆纤维填充PVC复合材料的相容性具有更高的效率和更良好的效果。     

相容剂对生物质纤维/废旧塑料复合材料的影响

通过加入不同的偶联剂马来酸酐接枝聚丙烯(PP-g-MAH)、硅烷、钛酸脂、DN-302研究了在偶联剂含量相同的情况下生物质纤维/废旧塑料复合材料的力学性能,得到了适于该复合材料的偶联剂,并对其最佳含量进行了探究。实验结果表明:采用PP-g-MAH偶联剂较好,当其质量分数为4%时,复合材料的综合力学性能最好。     

正辛醇接枝改性杉木粉的制备及其对PPI杉木粉复合材料性能的影响

以甲苯二异氰酸酯（TDI）为偶联剂将正辛醇接枝到杉木粉表面,同时考察处理前后杉木粉填充PP复合材料的力学性能。通过红外光谱分析（FTIR）,扫描电子显微镜分析（SEM）等方法对材料的结构进行了分析。结果表明：与未接枝改性杉木粉相比接枝改性杉木粉/PP复合材料的力学性能显著提高,其拉伸强度和冲击强度可分别提高44．3％和65.0％。扫描电镜照片显示正辛醇接枝改性杉木粉在基体中分散更均匀。     

PP/生物质灰复合材料的制备与力学性能研究

采用熔融共混工艺制备了聚丙烯(PP)/生物质灰复合材料,考察了生物质灰用量、偶联剂处理和马来酸酐接枝PP增容剂(PP-g-MAH)对复合材料力学性能的影响.研究发现,生物质灰用量为20份时,复合材料的拉伸强度和冲击强度较纯PP的性能有所提高;偶联剂KH550用量为生物质灰用量的l%时效果较好;PP-g-MAH增容剂对复合材料的增容效果明显,使材料的力学性能提高.     

硅烷偶联剂改性芳纶的性能测试

采用硅烷偶联剂对芳纶进行改性,然后用傅里叶红外光谱仪、单一纤维接触角测试仪和X射线衍射仪对改性前后的芳纶进行测试、观察并分析。结果显示:红外光谱分析表明芳纶的改性发生在纤维的表面,并没有对纤维大分子产生明显破坏;接触角测试表明改性后芳纶的接触角变小,说明KH550硅烷偶联剂可改善芳纶的亲水性;X射线衍射测试表明芳纶结晶度有所下降,可以更好地与树脂黏结。     

Effect of macromolecular coupling agent on the property of PP/GF composites

Silane‐grafted polypropylene manufactured by a reactive grafting process was used as the coupling agent in polypropylene/glass‐fiber composites to improve the interaction of the interfacial regions. Polypropylene reinforced with 30% by weight of short glass fibers was injection‐molded and the mechanical behaviors were investigated. The results indicate that the mechanical properties (tensile strength, tensile modulus, flexural strength, flexural modulus, and Izod impact strength) of the composite increased remarkably as compared with the noncoupled glass fiber/polypropylene. SEM of the fracture surfaces of the coupled composites shows a good adhesion at the fiber/matrix interface: The fibers are coated with matrix polymer, and a matrix transition region exists near the fibers. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1537–1542, 1999     

Composition,tensile properties,and dispersion of polypropylene composites reinforced with viscose fibers

The reinforcement mechanics of viscose‐fiber‐reinforced polypropylene (PP) composites were studied. The effect of the coupling agent, maleated polypropylene (MAPP), was of special interest. The fibers, coupling agent, and PP were extruded and injection‐molded. The composition, mechanical properties, fracture morphology, and dispersion of the composites were examined. Thermogravimetric analysis showed that the fiber content in the tensile specimens varied slightly with the sample location; however, the differences in the values were within 1.0%. Scanning electron microscopy images of the fracture surfaces of the composites showed that the surfaces of the composites without MAPP were covered with fibers pulled out from the matrix. A lack of adhesion further appeared as a cracked matrix–fiber interface. A new scanning thermal microscopy method, microthermal analysis, was used to study the dispersion of the fibers in the composites. Local thermal analyses gave further information about the location of the fibers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2676–2684, 2004     

酸式磷酸二辛酯的合成及其在膨胀型阻燃聚丙烯中的偶联作用

以三氯氧磷、异辛醇为原料合成的酸式磷酸二辛酯是一种含磷阻燃偶联剂 ,作者研究了其对膨胀型阻燃剂 (IFR) /聚丙烯 (PP)共混材料的偶联作用。力学性能、阻燃性能测试和SEM结果表明 :酸式磷酸二辛酯是体系有效的偶联剂 ,在不损害原有阻燃性能的条件下 ,提高了共混材料的力学性能 ,明显改善共混体系的形貌结构 ,是一种可选的阻燃偶联剂。经酸式磷酸二辛酯偶联的IFR/PP拉伸强度、抗冲击强度和水平燃烧性能分别为 2 5 4MPa、4 0 2kJ·m-2 和GB 2 40 8—80II- 0 5mm ,离火 36s自熄 ,未加偶联剂的对应值为 2 2 5 7MPa、3 2 7kJ·m-2 和GB 2 40 8— 80II- 1mm ,离火 39s自熄。     

Effect of ultrasound on wettability between aramid fibers and epoxy resin

Good wetting of reinforced fiber by resin was a main factor in the improvement of the interface adhesion of their composites. Ultrasound with a frequency of 20 kHz was used to improve the wettability between aramid fibers and epoxy resin during the winding process of the composites. The effects of ultrasound on the viscosity and surface tension of epoxy resin and on the surface characteristics of aramid fibers were investigated. The wettability of aramid fibers and treated epoxy resin under different conditions and of aramid fibers and epoxy resin under ultrasonic online treatment were compared. The results indicated that the main action of ultrasound was to force epoxy resin to impregnate aramid fibers, in addition to the influence of ultrasound on the properties of epoxy resin and aramid fibers. The results of microdebond testing showed that the interfacial shear strength (IFSS) of aramid/epoxy composites could be 26% higher than that of untreated composites because of the improved wettability between aramid fibers and epoxy resin subjected to ultrasonic online treatment. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Comparison of the effects of polyethylenimine and maleated polypropylene coupling agents on the properties of cellulose‐reinforced polypropylene composites

The desire to improve the properties of cellulose‐reinforced composites while producing them by methods as similar as possible to those used on an industrial scale is one of the driving forces in this field of research. In this work, extensive research for determining the mechanical, thermal, rheological, and physical properties of novel cellulose‐reinforced polypropylene composites containing a polyethylenimine (PEI) coupling agent was conducted. A comparison of their properties with those of reference composites without any coupling agent or containing a maleated polypropylene (MAPP) coupling agent was also carried out. The presence of the PEI coupling agent mainly gave rise to a substantial increase in the tensile and flexural strengths and elongations as well as the impact strength, heat deflection temperature (HDT), melt volume flow index, and water absorption of PEI‐containing composites in comparison with composites without any coupling agent added. However, the increases achieved in the tensile and flexural composite strengths and HDT were lower than those achieved with the MAPP coupling agent mainly for composites containing 50 wt % cellulose fibers. On the other hand, PEI‐containing composites exhibited, in most cases, larger elongations and energies required to break in tensile tests as well as larger impact strengths, melt volume flow indices, and water absorption percentages than MAPP‐containing composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Characterization and properties of activated nanosilica/polypropylene composites with coupling agents

In this work, nanosilica/polypropylene composites containing 1 wt% of silica nanoparticles were prepared by melt mixing in a Thermo Haake internal mixer. Prior compounding, nanosilica was subjected to surface activation using sodium hydroxide (NaOH) solution. The effectiveness of the activation process was evaluated by measuring the amount of hydroxyl groups ( OH) on the surface of nanosilica via titration method and supported by FTIR analysis. Two coupling agents namely 3‐aminopropyl triethoxysilane (APTES) and neopentyl (diallyl)oxy, tri(dioctyl) phosphate titanate (Lica 12) were used for surface treatment after activation process. The mechanical properties of polypropylene matrix reinforced with silica nanoparticles were determined by tensile and impact test. Hydroxyl groups on the nanosilica surface played an important role in enhancing the treatment with silane coupling agents. To increase the amount of hydroxyl groups on the nanosilica surface, the optimum concentration of NaOH is 1 mol%. Tensile strength, tensile modulus, and impact strength of nanosilica/PP composites improved with activation process. As the coupling agent is concerned, APTES coupling agent is more pronounced in enhancing the mechanical properties of the composites when compared with Lica 12 coupling agent. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Comparative study of the effects of different fibers on the processing and properties of ternary composites based on PP-EPDM blends

The effects of the incorporation of different kinds of fibers on the physical and mechanical properties of thermoplastics elastomers based on blends of isotactic polypropylene (iPP) and ethylene-propylene diene rubber (EPDM) are described. For this purpose, three different compositions of PP-EPDM blends reinforced with fibers are studied and reported here. In particular, the flow behavior, mechanical properties (tensile, flexural and impact resistance) and morphology are examined. Rheological measurements confirm the viscosity increase of thermoplastics elastomers with the incorporation of the fibers. This increment is more evident in the presence of aramid fibers. In addition, the results obtained by dynamic-mechanical analysis and mechanical properties show that the fibers act as an effective reinforcing agent of PP-EPDM blends. In fact, a significant increase of the modulus and strength is obtained in presence of all fibers, this effect being more noticeable at higher elastomer percentages in the thermoplastic. The morphology of the ternary composites is also analyzed by scanning electron microscopy (SEM). A good interfacial adhesion between fibers and matrix is observed, but also in this case, aramid fibers are the most effective ones.     

RETRACTED ARTICLE: Surface modification of aramid fibers with novel chemical approach

Friedel–Crafts Reaction as a simple and convenient approach to the surface modification of aramid fiber was introduced in this paper. Epoxy chloropropane was chosen as the treatment reagent to modify aramid fibers surface via Graft reaction. After the modification, the interfacial properties of aramid/epoxy composites were investigated by the single fiber pull-out test (SFP), and the mechanical properties of aramid fibers were investigated by the tensile strength test. The results showed that the interfacial shear strength (IFSS) value of aramid/epoxy composites was enhanced by about 50%, and the tensile strength of aramid fibers had no obvious damage. The crystalline state of aramid fibers was determined by X-ray diffraction instrument (XRD), and the results showed that there were not any distinct crystal type varieties. The surface elements of aramid fibers were determined by X-ray photoelectron spectroscopy (XPS), the analysis of which showed that the oxygen/carbon ratio of aramid fiber surface increased obviously. The possible changes of the chemical structure of aramid fibers were investigated via Fourier transform infrared spectrum (FTIR), and the analysis of which showed that the epoxy functional groups were grafted into the molecule structure of aramid fibers. The surface morphology of aramid fibers was analyzed by Scanning electron microscope (SEM), and the SEM results showed that the physical structure of aramid fibers was not etched or damaged obviously. The surface energy of aramid fibers was investigated via the dynamic capillary method, and the results showed that the surface energy was enhanced by 31.5%, and then the wettability degree of aramid fiber surface was enhanced obviously too. All of the results indicated that this novel chemical modification approach not only can improve the interfacial bonding strength of aramid/epoxy composites remarkably, but also have no negative influence on the intrinsic tensile strength of aramid fibers.     

Mechanical properties and water absorption of fiber‐reinforced polypropylene composites prepared by bagasse and beech fiber

The present study investigates the tensile, flexural, notched Izod impact, and water absorption properties of bagasse and beech reinforced polypropylene (PP) composites as a function of fiber content. The surface of fibers was modified through the use of maleated polypropylene (MAPP) coupling agent. From this study, it was found that mechanical properties increase with an increase in fiber loading in both cases. However, the addition of wood fibers resulted in a decrease in impact strength of the composites. The water absorption property at varying fiber loading was evaluated and found maximum for the BA/PP composites. The weight gains for all specimens were less than 7%. In general, the results showed the usefulness of bagasse fiber as a good alternative and reinforcing agent for composite. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009