Enhancing interfacial adhesion performance by using poly(vinyl alcohol) in (low‐density polyethylene)/(natural rubber)/(water hyacinth fiber) composites

The effects of (a) the chemical modification of water hyacinth fiber by poly(vinyl alcohol) (WHF‐_PVA) and (b) loading on the properties of low‐density polyethylene (LDPE)/(natural rubber (NR))/(water hyacinth fiber (WHF)) composites were studied. Mechanical properties, water absorption behavior, morphology, and thermal properties were examined; X‐ray diffraction and infrared spectroscopic analysis were done. The results indicated that LDPE/NR/WHF‐_PVA composites had higher values of tensile strength, Young's modulus, melting temperature, and water absorption resistance but lower elongation at break than LDPE/NR/WHF composites. The LDPE/NR/WHF‐_PVA composites had better interfacial adhesion between the matrix and the fibers than LDPE/NR/WHF composites, as shown by SEM results. The LDPE/NR/WHF‐_PVA composites exhibited lower interparticle spacing than LDPE/NR/WHF composites, a feature which enhanced the interparticle interaction between the water hyacinth fibers and the LDPE/NR matrix. J. VINYL ADDIT. TECHNOL., 19:47–54, 2013. © 2012 Society of Plastics Engineers     

Effect of Poly(methyl Methacrylate) Modified Water Hyacinth Fiber on Properties of Low Density Polyethylene/Natural Rubber/Water Hyacinth Fiber Composites

The effect of poly(methyl methacrylate) modified water hyacinth fiber on properties of low density polyethylene (LDPE)/natural rubber (NR)/water hyacinth fiber (WHF) composites were investigated. The composites were prepared with Z-blade mixer at 180°C and rotor speed of 50 rpm. The poly(methyl methacrylate) modified water hyacinth fibers in LDPE/NR composites (LDPE/NR/WHF-_PMMA) gave a greater value of tensile strength, Young's modulus, glass transition temperature (Tg), melting temperature (Tm), and % crystallinity compared to unmodified water hyacinth fibers in LDPE/NR composites (LDPE/NR/WHF). FTIR analysis shows the presence of ester carbonyl group and C-O ester group in poly (methyl methacrylate) modified water hyacinth fiber. The SEM micrograph also shows a better interfacial adhesion between the fibers and LDPE/NR matrixes for LDPE/NR/WHF-_PMMA composites than LDPE/NR/WHF composites. LDPE/NR/WHF-_PMMA composites had a lower value of interparticle spacing compared to LDPE/NR/WHF composites thatenhanced the interparticle interaction between fiber and LDPE/NR matrixes.     

Properties of (Low‐density polyethylene)/(natural rubber)/(water hyacinth fiber) composites: The effect of polyaniline

The effects of polyaniline (PANI)‐modified water hyacinth fiber on the properties of (low‐density polyethylene)/(natural rubber)/(water hyacinth fiber) (LDPE/NR/WHF) composites were studied. The composites were prepared by using a Brabender Plasticorder at 160^oC and a rotor speed of 50 rpm for 6 minutes. LDPE/NR/WHF_PANI composites exhibited higher tensile strength, Young's modulus, elongation at break, melting temperature, and electrical conductivity but lower molar sorption, capacitance, percentage crystallinity, and interparticle spacing than LDPE/NR/WHF composites. Scanning electron microscopy morphology showed a better interfacial adhesion of PANI‐modified water hyacinth fiber (WHF_PANI) and the LDPE/NR phases than when unmodified WHF was used. J. VINYL ADDIT. TECHNOL., 20:122–130, 2014. © 2014 Society of Plastics Engineers     

Effect of filler loading and coconut oil coupling agent on properties of low‐density polyethylene and palm kernel shell eco‐composites

Palm kernel shell (PKS), a waste from the oil palm industry, has been utilized as filler in low‐density polyethylene (LDPE) eco‐composites in the present work. The effect of PKS content and coconut oil coupling agent (COCA) on tensile properties, water absorption, and morphological and thermal properties of LDPE/PKS eco‐composites was investigated. The results show the increase of PKS content decreased the tensile strength and elongation at break, but increased the tensile modulus, crystallinity, and water absorption of eco‐composites. The presence of COCA as coupling agent improved the filler‐matrix adhesion yield to increase the tensile strength, tensile modulus, crystallinity, and reduced water absorption of eco‐composites. The better interfacial adhesion between PKS and LDPE with the addition of COCA was also evidenced by scanning electron microscopy studies. J. VINYL ADDIT. TECHNOL., 22:200–205, 2016. © 2014 Society of Plastics Engineers     

Improving the properties of LDPE/glass fiber composites with silanized-LDPE

Low density polyethylene (LDPE) is a widely used thermoplastic. The dispersion of inorganic fillers in thermoplastic matrices such as polyethylene has been largely employed to improve some of its properties. However, interaction between both components is a major issue so the presence of a coupling agent is usually necessary to increase the interaction among the phases. In this study, LDPE chemically modified with vinyltriethoxysilane (VTES) was used as a coupling agent in glass fiber-reinforced LDPE. The composites were prepared in a mixing chamber and subsequently analyzed by tensile tests, rotational rheometry, and scanning electron microscopy (SEM). The mechanical properties were significantly increased by the use of small amounts of the coupling agent. Moreover, the rheological behavior and the SEM micrographs showed higher interaction between the matrix and the reinforcing phase in the composites containing LDPE modified with VTES, confirming the suitability of using this coupling agent in these systems. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Effects of chemical modification of epoxy‐(ethylene diamine) on water hyacinth fibers (Eichhornia crassiper)‐filled (low‐density polyethylene)/(natural rubber) blends

The effects of modification by epoxy‐(ethylene diamine) (EED) on (water hyacinth fiber)‐filled (low‐density polyethylene)/(natural rubber) (LDPE/NR/WHF_‐EED) composites were studied. The LDPE/NR/WHF and LDPE/NR/WHF_‐EED composites were prepared by using a Brabender Plasticorder. LDPE/NR/WHF_‐EED showed higher tensile strength, Young's modulus, and elongation at break but lower molar sorption of toluene compared with LDPE/NR/WHF composites. The Fourier‐transform infrared radiation analysis indicated that the absorption peak at 1,648 cm^?1 exhibited the C? N band. This C? N band was formed from the bond of the epoxy group and the amine group in the WHF‐g‐epoxy‐(ethylene diamine) (WHF_‐EED). The scanning electron microscopic morphology of LDPE/NR/WHF_‐EED composites displayed rougher surfaces and less fiber pull, which improved the interfacial adhesion among the fiber/matrix. J. VINYL ADDIT. TECHNOL., 20:201–209, 2014. © 2014 Society of Plastics Engineers     

Effect of Vinyl Alcohol-Phthalic Anhydride on Properties of Low Density Polyethylene (LDPE)/Tyre Dust (TD) Composites

The effect of vinyl alcohol-phthalic anhydride as a coupling agent on the tensile properties, morphology, and thermal degradation of low density polyethylene/tyre dust (LDPE/TD) composites was studied. LDPE/TD composites with different tyre dust loading and the addition of vinyl alcohol-phthalic anhydride were prepared with Z-blade mixer at 180°C and rotor speed of 50 rpm. The result indicated that LDPE/TD_M composites with vinyl alcohol-phthalic anhydride show higher values of tensile strength, Young's modulus and mass swell, but lower elongation at break than LDPE/TD composites without vinyl alcohol-phthalic anhydride. The SEM micrographs showed that the tyre dust was more widely dispersed in the LDPE matrix with the addition of vinyl alcohol-phthalic anhydride as a coupling agent. It was also found that the addition of vinyl alcohol-phthalic anhydride offers better thermal stability in the LDPE/TD_M composites than LDPE/TD composites.     

Banana fiber reinforced low-density polyethylene composites: effect of chemical treatment and compatibilizer addition

In this study, an attempt has been made to utilize banana fiber (a natural fiber from agricultural waste) as reinforcement for low-density polyethylene (LDPE) to develop environmental friendly composite materials. LDPE/banana fiber composites were fabricated at different fiber loadings (10, 15, 20, 25, and 30 wt %) using compression molding technique. The composite with the composition of 25 wt % banana fiber was observed to be optimum on the basis of biodegradability and mechanical properties. Further, the effect of banana fiber surface treatment (alkali and acrylic acid) on the mechanical properties, morphology and water absorption behavior of the LDPE/banana fiber composites in the absence and presence of compatibilizer (maleic anhydride grafted LDPE, MA-g-LDPE) was comparatively studied. The alkali and acrylic acid treatment of the banana fibers led to enhanced mechanical properties and water resistance property of the composites, and these properties got further improved by the addition of the compatibilizer. The addition of compatibilizer to the acrylic acid treated banana fiber composites showed the most effective improvement in the flexural and impact strength and also, exhibited a reduction in the water absorption capacity. However, the tensile strength of the compatibilized composites with treated fibers resulted in slightly lower values than those with untreated fibers, because of the degradation of fibers by chemical attack as was evidenced by scanning electron microscopy (SEM) micrographs. SEM studies carried out on the tensile fractured surface of the specimens showed improved fiber-matrix interaction on the addition of compatibilizer.     

低密度聚乙烯/氧化锌复合材料制备及其隔声性能研究

采用钛酸酯偶联剂对氧化锌(ZnO)进行表面改性,改性ZnO与低密度聚乙烯(LDPE)制备LDPE/ZnO复合材料。分析ZnO形貌及添加量对复合材料力学性能、阻尼性能、隔声性能及热稳定性的影响。结果表明:改性ZnO与LDPE具有良好的界面相容性,ZnO可以提升LDPE/ZnO复合材料的抗拉强度、隔声性能及热稳定性,四针状氧化锌(T-ZnO)添加量为5%时,复合材料的力学性能最好,综合性能最优。     

Characterization and Properties of Recycled Polypropylene/Coconut Shell Powder Composites: Effect of Sodium Dodecyl Sulfate Modification

This research work focuses on the utilization of coconut shell powder (CSP) as filler in recycled polypropylene (rPP). Sodium Dedecyl Sulfate (SDS) was used as coupling agent in these composites. The effect of filler content and SDS on tensile properties, thermal properties, water absorption and morphology of rPP/CSP composites were investigated. In this study, modified rPP/CSP composites with SDS show significant increased tensile propertied, thermal stability, crystallinity and low water absorption compared unmodified rPP/CSP composites. Those improvements were contributed by the coupling effect of SDS.     

Properties of Paper Sludge Filled Polypropylene (PP)/Ethylene Propylene Diene Terpolymer (EPDM) Composites: The Effect of Silane-Based Coupling Agent

Paper sludge was used as a filler in PP/EPDM composites and 3-aminopropyl triethoxysilane (3-APE) was used in this study as a coupling agent. The effects of filler loading and 3-APE on the mechanical properties, water absorption, morphology, and thermal properties of the composites were investigated. It was found that incorporation of a silane coupling agent (3-APE) increased the stabilization (equilibrium) torque, tensile strength, and Young's modulus but decreased the elongation at break and water absorption. Scanning electron microscopy (SEM) study of the tensile fracture surface of the composites indicated that the presence of 3-APE increased the interfacial interaction between paper sludge and PP/EPDM matrix. The addition of a silane coupling agent also increased the crystallinity of PP and thermal stability of PP/EPDM/PS composites.     

Study on Mechanical and Dielectric Properties of Jute Fiber Reinforced Low-Density Polyethylene (LDPE) Composites

Abstract

Jute fiber (Hessian cloth) reinforced low-density polyethylene (LDPE) composites were prepared by heat press molding techniques. The mechanical properties such as tensile strength (TS), bending strength (BS), and elongation at break of the composites were studied. The enhancement of TS (33%) and BS (50%) were obtained as a result of reinforcment jute fabrics in LDPE. In order to improve the mechanical properties and adhesion between jute and LDPE, hessian cloth were each treated with 2-hydroxyl ethyl methacrylate (HEMA). The HEMA-treated jute composite showed higher tensile and bending strength compared to untreated jute composite and LDPE. Dielectric properties like dielectric constant and loss tangent (tan δ) of jute, LDPE and composites were studied. Ferro to paraelectric phase transition occurred in both treated and untreated jute composites containing more than 20% jute. Water uptake behaviors of the composite were monitored and HEMA-treated composite showed lower water absorption behavior. The adhesion nature of jute and LDPE also characterized by scanning electronic microscopy (SEM), better adhesion was observed between HEMA-treated jute and LDPE over untreated ones.     

改性竹纤维增强聚丙烯复合材料的性能研究

以聚丙烯为基体材料,不同处理工艺改性的竹纤维为增强材料,采用密炼-注塑工艺制备聚丙烯/竹纤维复合材料。通过红外光谱仪(FTIR)、扫描电子显微镜(SEM)、热重分析仪(TGA)、万能试验机等对复合材料的化学结构、表面形态、热性能、力学性能等进行表征和测试。结果表明:偶联剂与碱处理均可改变竹纤维的表面特性,改善复合材料的界面相容性,其力学性能、热性能均随处理工艺有所改善。当偶联剂KH-550含量为2%时,复合材料有较好的力学性能,其断裂伸长率为14.5%,拉伸强度为30.48 MPa,冲击强度为22.4 kJ/m2。     

PBAT/木粉复合材料的制备

以木粉和聚己二酸/对苯二甲酸丁二酯(PBAT)为原料,添加硅烷偶联剂,混合均匀后,在开炼机中混炼一定时间制备PBAT/木粉复合材料,从偶联剂种类及其用量、加工温度、加工时间4个方面探讨了制备PBAT/木粉复合材料的最佳工艺条件。研究结果表明,加入的硅烷偶联剂KH–560用量为木粉和PBAT总质量的2%,与木粉和PBAT在130℃下混炼10 min,制备出的PBAT/木粉复合材料的相容性较好,且复合材料的拉伸性能达到最优,拉伸强度和断裂伸长率分别达到12.42 MPa和56.58%。SEM分析表明,添加KH–560后,PBAT/木粉的相容性得到了明显改善,耐水性更好,吸水率从13.04%下降到10.39%,制备出的PBAT/木粉复合材料的耐热性能较原料木粉也得到了较大的提高,在395℃时仅分解40%。     

Al-BaSO4/PE复合材料与临床材料性能对比

采用熔融共混方法制备了铝酸酯偶联剂改性硫酸钡(Al-BaSO4)/聚乙烯(PE)复合材料。重点研究了AlBaSO4与PE基体之间的界面结合机制,并且对Al-BaSO4/PE复合材料与临床应用复合材料进行了力学性能对比。运用X射线衍射(XRD)、X射线能谱仪(EDS)、扫描电镜(SEM)及万能拉伸试验等测试方法,表征了复合材料的结构、填料分布、形貌及力学性能。结果表明,铝酸酯偶联剂改善了BaSO4与PE的相容性,Al-BaSO4在聚乙烯基体中的分散性较好,Al-BaSO4/PE复合材料的力学性能优于临床应用产品的力学性能。Al-BaSO4/PE复合材料的拉伸强度与临床应用产品相比,提高了10.4%;断裂伸长率与临床应用产品相比,提高了14.2%;弯曲强度与临床应用产品相比提高了16.4%。     

Recycled milk pouch and virgin low‐density polyethylene/linear low‐density polyethylene based coir fiber composites

The viability of the thermomechanical recycling of postconsumer milk pouches [a 50 : 50 low‐density polyethylene/linear low‐density polyethylene (LDPE–LLDPE) blend] and their use as polymeric matrices for coir‐fiber‐reinforced composites were investigated. The mechanical, thermal, morphological, and water absorption properties of recycled milk pouch polymer/coir fiber composites with different treated and untreated fiber contents were evaluated and compared with those of virgin LDPE–LLDPE/coir fiber composites. The water absorption of the composites measured at three different temperatures (25, 45, and 75°C) was found to follow Fickian diffusion. The mechanical properties of the composites significantly deteriorated after water absorption. The recycled polymer/coir fiber composites showed inferior mechanical performances and thermooxidative stability (oxidation induction time and oxidation temperature) in comparison with those observed for virgin polymer/fiber composites. However, a small quantity of a coupling agent (2 wt %) significantly improved all the mechanical, thermal, and moisture‐resistance properties of both types of composites. The overall mechanical performances of the composites containing recycled and virgin polymer matrices were correlated by the phase morphology, as observed with scanning electron microscopy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Effects of (conductive polypyrrole)‐modified tire dust on the mechanical,electrical, and morphology properties of (low‐density polyethylene)/(tire dust) composites

The effects of conductive polypyrrole (PPy) as a coupling agent on the mechanical properties, morphology, electrical properties, and thermal degradation of (low‐density polyethylene)/(tire dust) (LDPE/TD) composites were studied. LDPE/TD composites with different TD loadings and added PPy were prepared with a Brabender Plasticorder. The LDPE/TD_T (treated with PPy) composites showed higher values of tensile strength, modulus of elasticity, electrical conductivity, thermal stability, and swelling resistance than LDPE/TD composites. Scanning electron microscopy morphology revealed that the interfacial adhesion between the TD and LDPE phases was improved by the addition of conductive PPy. J. VINYL ADDIT. TECHNOL., 20:131–136, 2014. © 2014 Society of Plastics Engineers     

Eco-friendly coupling agent-treated kenaf/linear low-density polyethylene/poly (vinyl alcohol) composites

Untreated kenaf (KNF) and eco-friendly coupling agent (EFCA)-treated kenaf were used as filler to prepare natural fiber-reinforced polymer composites (NFPCs) using linear low-density polyethylene (LLDPE) and poly(vinyl alcohol) (PVOH) as polymer matrices. The composites containing various loadings of untreated and EFCA-treated KNF (0, 10, 20, and 40 phr) were melt-blended in an internal mixer. The effect of treatment on the behavior of processing torque, mechanical properties, morphology, functional groups, water absorption, and thermal stability of KNF/LLDPE/PVOH composites were investigated. The results revealed that EFCA-treated KNF composites exhibited higher equilibrium torque, indicating that the viscosity of molten composites increased in the presence of EFCA. The tensile strength and tensile modulus of KNF/LLDPE/PVOH composites were improved with the addition of EFCA-treated KNF attributed to the enhancement of the interfacial adhesion between KNF and LLDPE/PVOH matrices, as confirmed by field-emission scanning electron microscopy. Fourier transform infrared spectroscopy indicated the presence of ester bond in EFCA-treated KNF composites. Furthermore, EFCA-treated KNF composites possessed a lower water absorption and greater thermal stability as compared to untreated KNF composites. Therefore, EFCA could be suggested as an effective coupling agent to enhance the performance of KNF/LLDPE/PVOH composites.     

Effect of proton irradiation on mechanical properties of low‐density polyethylene/multiwalled carbon nanotubes composites

The mechanical properties of low‐density polyethylene/multiwalled carbon nanotubes (LDPE/MWCNTs) composites without and with 170 keV proton irradiation were studied by tensile tests. Mechanisms of changes of mechanical properties were examined by means of small angle X‐ray scattering (SAXS), wide angle X‐ray diffraction (WAXD), Raman spectroscopy, and scanning electron microscopy (SEM). The tensile curve of LDPE exhibits three characteristic regions, while those for LDPE/MWCNTs composites only give the first and the second ones. The tensile curves of all samples with 170 keV proton irradiation have no obvious yield phenomenon. The addition of MWCNTs increases the ultimate tensile strength and decreases the elongation at break. Moreover, the ultimate tensile strengths of both LDPE and LDPE/MWCNTs composites with 170 keV proton irradiation are enhanced, and the elongations at break for them are decreased. Based on the analyses of SAXS, WAXD, Raman spectroscopy, and SEM, both the loading of MWCNTs and the proton irradiation can change the mechanical properties of LDPE/MWCNTs composites by a number of factors including the homogeneous distribution of MWCNTs in LDPE matrix, the aberrance zone between MWCNTs, and LDPE matrix, the interaction between MWCNTs and LDPE matrix, and the crystallinities of samples. POLYM. COMPOS., 36:278–286, 2015. © 2014 Society of Plastics Engineers     

Influence of grafted polypropylene on the mechanical properties of mineral‐filled polypropylene composites

The purpose of this work was to study how mineral fillers would behave in a polypropylene (PP) matrix when PP modified with maleic anhydride (MA) and/or itaconic acid (IA) was used as a coupling agent in the preparation of mineral‐filled PP composites. The composites were characterized with tensile mechanical measurements and morphological analysis. The optimum amount of the coupling agent to be used to obtain composites with improved mechanical properties was established. The results indicated that these coupling agents enhanced the tensile strength of the composites significantly, and the extent of the coupling effect depended on the nature of the interface that formed. The incorporation of coupling agents enhanced the resistance to deformation of the composite. The behavior of IA‐modified PP as a coupling agent was similar to that of a commercial MA‐modified PP for the filled PP composites. Evidence of improved interfacial bonding was revealed by scanning electron microscopy studies, which examined the surfaces of fractured tensile test specimens; their microstructures confirmed the mechanical results with respect to the observed homogeneous or optimized dispersion of the mineral‐filler phase in these composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2343–2350, 2007