Mechanical,thermal, and morphological properties of maleic anhydride‐g‐polypropylene compatibilized and chemically modified banana‐fiber‐reinforced polypropylene composites

Composites were prepared with chemically modified banana fibers in polypropylene (PP). The effects of 40‐mm fiber loading and resin modification on the physical, mechanical, thermal, and morphological properties of the composites were evaluated with scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Infrared (IR) spectroscopy, and so on. Maleic anhydride grafted polypropylene (MA‐g‐PP) compatibilizer was used to improve the fiber‐matrix adhesion. SEM studies carried out on fractured specimens indicated poor dispersion in the unmodified fiber composites and improved adhesion and uniform dispersion in the treated composites. A fiber loading of 15 vol % in the treated composites was optimum, with maximum mechanical properties and thermal stability evident. The composite with 5% MA‐g‐PP concentration at a 15% fiber volume showed an 80% increase in impact strength, a 48% increase in flexural strength, a 125% increase in flexural modulus, a 33% increase in tensile strength, and an 82% increase in tensile modulus, whereas the heat deflection temperature increased by 18°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Influence of organically modified nanoclay on the performance of pineapple leaf fiber‐reinforced polypropylene nanocomposites

Polypropylene/Pine apple leaf fiber (PP/PALF)‐reinforced nanocomposites were fabricated using melt blending technique in a twin‐screw extruder (Haake Rheocord 9000). Variation in mechanical properties, crystallization behavior, water absorption, and thermal stability with the addition of nanoclay in PP/PALF composites were investigated. It was observed that the tensile, flexural, and impact properties of PP increase with the increase in fiber loading from 10 to 30 wt %. Composites prepared using 30 wt % PALF and 5 wt % MA‐g‐PP exhibited optimum mechanical performance with an increase in tensile strength to 31%, flexural strength to 45% when compared with virgin PP. Addition of nanoclay results in a further increase in tensile and flexural strength of PP/PALF composites to 20 and 24.3%, which shows intercalated morphology. However, addition of nanoclay does not show any substantial increase in impact strength when compared with PP/PALF composites. Dynamic mechanical analysis tests revealed an increase in storage modulus (E′) and damping factor (tan δ), confirming a strong influence between the fiber/nanoclay and MA‐g‐PP. Differential scanning calorimetry, thermogravimetric analysis thermograms also showed improved thermal properties when compared with the virgin matrix. TEM micrographs also showed few layers of agglomerated clay galleries along with mixed nanomorphology in the nanocomposites. Wide angle X‐ray diffraction studies indicated an increase in d‐spacing from 22.4 Å in Cloisite 20A to 40.1 Å in PP/PALF nanocomposite because of improved intercalated morphology. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Influence of interfacial adhesion on the structural and mechanical behavior of PP‐banana/glass hybrid composites

Hybrid composites of polypropylene (PP), reinforced with short banana and glass fibers were fabricated using Haake torque rheocord followed by compression molding with and without the presence maleic anhydride grafted polypropylene (MAPP) as a coupling agent. Incorporation of both fibers into PP matrix resulted in increase of tensile strength, flexural strength, and impact strength upto 30 wt% with an optimum strength observed at 2 wt% MAPP treated 15 wt% banana and 15 wt% glass fiber. The rate of water absorption for the hybrid composites was decreased due to the presence of glass fiber and coupling agent. The effect of fiber loading in presence of coupling agent on the dynamic mechanical properties has been analyzed to investigate the interfacial properties. An increase in storage modulus (E′) of the treated‐composite indicates higher stiffness. The loss tangent (tan δ) spectra confirms a strong influence of fiber loading and coupling agent concentration on the α and β relaxation process of PP. The nature of fiber matrix adhesion was examined through scanning electron microscopy (SEM) of the tensile fractured specimen. Thermal measurements were carried out through differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA), indicated an increase in the crystallization temperature and thermal stability of PP with the incorporation of MAPP‐treated banana and glass fiber. POLYM. COMPOS., 31:1247–1257, 2010. © 2009 Society of Plastics Engineers     

Mechanical and thermal properties of polypropylene nanocomposites using organically modified Indian bentonite

We report preparation and characterization of nanoclay from Indian bentonite and imported nanoclays, and their compounding with polypropylene (PP) and maleic anhydride‐grafted PP (MA‐g‐PP) in twin screw extruder. The compounded polymer/nanoclay nanocomposites (PNCs) are molded into a standard specimen for studying its tensile, flexural and impact strength. A wide angle X‐ray diffraction (WAXD) and transmission electron microscopy (TEM) study demonstrates intercalation of PP in nanoclays rather than exfoliation for both, indigenous and imported nanoclays. The tensile modulus increased by 41 and 39% for PNC1 (PNC with imported nanoclay) and PNC2 (PNC with indigenous nanoclay) with respect to PP. The flexural modulus for PNC1 and PNC2 also increases by 23 and 22% due to incorporation of 5% nanoclay in PP along with 5% MA‐g‐PP. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Bamboo fiber reinforced polypropylene composites and their mechanical,thermal, and morphological properties

Short bamboo fiber reinforced polypropylene composites were prepared by incorporation of various loadings of chemically modified bamboo fibers. Maleic anhydride grafted polypropylene (MA‐g‐PP) was used as compatibilizer to improve fiber–matrix adhesion. The effects of bamboo fiber loading and modification of the resin on the physical, mechanical, thermal, and morphological properties of the bamboo reinforced modified PP composites were studied. Scanning electron microscopy studies of the composites were carried out on the interface and fractured surfaces. Thermogravimetric analysis and IR spectroscopy were also carried out. At 50% volume fraction of the extracted bamboo fiber in the composites, considerable increase in mechanical properties like impact, flexural, tensile, and thermal behavior like heat deflection temperature were observed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Banana/Glass Fiber-Reinforced Polypropylene Hybrid Composites: Fabrication and Performance Evaluation

Hybrid composites of Polypropylene (PP) reinforced with intimately mixed short banana and glass fibers were fabricated using Haake twin screw extruder followed by compression molding with and without the presence maleic anhydride grafted polypropylene (MAPP) as a coupling agent. Incorporation of both the fibers into PP matrix resulted in an increase in tensile, flexural and impact strength with an increasing level of fiber content upto 30 wt% at banana: glass fiber ratio of 15:15 wt% and 2 wt% of MAPP. The rate of water absorption for the hybrid composites decreased due to the presence of glass fiber and coupling agent. The effect of fiber loading in presence of coupling agent on the dynamic mechanical properties has also been analyzed to investigate the interfacial properties. An increase in the storage modulus (E′) of the treated composite indicates higher stiffness. The tan δ spectra confirms a strong influence of fiber contents and coupling agent on the α and β relaxation processes of PP. The nature of fiber matrix adhesion was examined through scanning electron microscopy (SEM) of the tensile fractured specimen. Thermal measurements were carried out employing differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA) which indicated a decrease in the crystallization temperature and thermal stability of PP with the incorporation of MAPP treated banana and Glass fiber.     

Study of effect of old corrugated cardboard in properties of polypropylene composites: Study of mechanical properties,thermal behavior,and morphological properties

The investigation of the economical use of lignocellulose waste, which is one of the environmental problems facing nations, is ongoing. In this study, waste cardboard paper fiber reinforcing polypropylene (PP) composites was developed. In order to modify the PP matrix maleated PP (MA‐g‐PP) a 5 wt% and a grafting rate of 1 and 2 wt% was used as a compatibilizer. The effects of fiber and compatibilizer content as well as graft content are evaluated by mechanical, thermal property measurements, and scanning electron microscopy (SEM). The compatibilizer improved all mechanical properties significantly. Thus, the tensile strength of MA‐g‐PP‐containing composites increases compared to PP/cardboard composites paper content increases. However, the tensile modulus of a PP‐based composite increases with an increase in paper fiber with the compatibilizer having little effect. SEM revealed that the addition of MA‐g‐PP generates strong interactions between a PP matrix and paper fibers. However, the addition of the MA‐g‐PP compatibilizing agent gives a significant improvement on the crystallization of the composites, whereas the compatibilized PP/old corrugated cardboard (OCC) composites have higher crystallinity (Xc) than uncompatibilized PP/OCC composites. The MA‐g‐PP also diminished the water absorption in the composites. J. VINYL ADDIT. TECHNOL., 22:231–238, 2016. © 2014 Society of Plastics Engineers     

Improved mechanical and thermal properties of bamboo–epoxy nanocomposites

Natural fiber‐reinforced hybrid composites based on bamboo/epoxy/nanoclay were prepared. Ultrasound sonication was used for the dispersion of nanoclay in the bamboo–epoxy composites. The morphology of bamboo–epoxy nanocomposites was investigated by using scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction. The results show that there exists an optimum limit in which the mechanical properties of composites improved by continuously increasing the nanoclay content. The tensile and flexural strength of bamboo–epoxy nanocomposites with 3 wt% nanoclay increased by 40% and 27%, respectively, as compared to pure composites. The highest value of impact strength was obtained for 1 wt% nanoclay content bamboo–epoxy nanocomposites. The enhanced impact strength of bamboo–epoxy nanocomposites was one of the key advantages brought by nanofiller. The results show that incorporation of nanoclay substantially increases the water resistance capability and thermal stability of bamboo–epoxy nanocomposites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Effect on modified nanoclay on dynamic mechanical and thermomechanical properties of natural fiber/polypropylene biocomposites

This study was conducted to investigate the effect of nanoclay addition on thermal and dynamic mechanical properties of polypropylene (PP) biocomposites reinforced with bleached red algae fiber (BRAF), kenaf fiber (KF), and cotton pulp fiber (CPF). The nano-biocomposites were fabricated with 40?wt.% loading of all natural fibers and addition of nanoclay at 5 or 10?wt.% loading by the melting compounding and compression molding techniques. The nanoclay effects on the thermal and dynamic mechanical properties of the biocomposites were analyzed as a function of properties of natural fibers such as chemical composition, fiber length, and surface morphology. Although the thermal decomposition temperature of nano-biocomposites decreased with the addition of nanoclay, the dimensional stability of biocomposites greatly improved with increasing nanoclay loading. Also, the dynamic mechanical properties of nano-biocomposites for the PP reinforced with BRAF, KF, and CPF were enhanced with the addition of 5?wt% nanoclay compared to those of biocomposites without nanoclay. The highest enhancement in dimensional stability was obtained for the nano-biocomposites reinforced with BRAF natural fiber. These increases can be attributed to a uniform distribution of nanoclay and to a good interfacial adhesion between the reinforcement and PP matrix. The well dispersed nanoclay particles can have good interactions with both natural fibers and polymer matrix, with the incorporation of the reinforcing natural fibers restricting the mobility of the polymer molecules resulting in the raised storage modulus values.     

Manufacture and properties of a structural synthetic polymer fiber‐containing nanoclay for concrete reinforcement

This study established the optimum conditions for structural synthetic polymer fiber manufacture to make a fiber having excellent tensile strength. Two polypropylene resins, differing in their melt indices, and four different draw ratio values were investigated, that is, 6, 7, 8, and 9, to establish which had the greatest influence on tensile strength. The tensile strength and the modulus of elasticity were measured for the manufactured fibers. In addition, nanoclay was added to polypropylene and polyolefin fibers to improve the mechanical properties of fiber‐reinforced cementitious composites. The optimum mixing ratio and draw ratio of the synthetic polymer fibers were established prior to nanoclay addition. Fiber mixing ratios (polypropylene:polyethylene) of 100:0, 90:10, and 85:15, a draw ratio of 8, and nanoclay additions of 1, 3, and 5 wt% were studied. The modulus of elasticity improved with nanoclay addition, while the tensile strength remained almost unchanged, except in the case of 100% polypropylene with 5 wt% nanoclay. POLYM. COMPOS., 34:1698–1709, 2013. © 2013 Society of Plastics Engineers     

A comparative study on some properties of wood plastic composites using canola stalk,Paulownia, and nanoclay

In this research, the reinforcing effect of fillers including canola stalk, paulownia and nanoclay, in polypropylene (PP) has been investigated. In the sample preparation, 50 wt% of lignocellulosic materials and 0, 3, and 5 wt% of nanoclay particles were used. The results showed that while flexural and tensile properties were moderately enhanced by the addition of nanoclay in the matrix, notched Izod impact strengths decreased dramatically. However, with increase in the nanoclay content (5 wt%), the flexural and tensile properties decreased considerably. The mechanical properties of composites filled with paulownia are generally greater than canola stalk composites, due to the higher aspect ratio. The thickness swelling and water absorption of the composites significantly decreased with the increase in nanoclay loading. Except tensile modulus, the differences between the type of fibrous materials and nanoclay contents had significant influence on physicomechanical properties. Morphologies of the composites were analyzed using transmission electron microscopy (TEM) and X‐ray diffraction (XRD), and the results showed increased d‐spacing of clay layers indicating enhanced compatibility among PP, clay, and lignocellulosic material. TEM micrographs also confirmed that the composites containing 3 wt% nanoclay had uniform dispersion and distribution of clay layers in the polymer matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation and characterization of nanoclay‐filled polyurethane/polypropylene blends

Ester‐based thermoplastic polyurethane (TPU) nanocomposites were prepared by melt blending at 190°C, using 3 wt% Cloisite 10A (organically modified montmorillonite clay) as the nanoscale reinforcement [TPU(C10A)]. The nanocomposites were subsequently melt‐blended with polypropylene (PP) using maleic anhydride–grafted polypropylene (MA‐g‐PP) as a compatibilizer [in the ratio of 70/30‐TPU/PP, 70/25/5‐TPU/PP/MA‐g‐PP, 70/25/5‐TPU (C10A)/PP/MA‐g‐PP]. Besides giving substantial increase in modulus, tensile strength, and other properties, organoclay reinforcement functions as a surface modifier for TPU hard segment resulting in improved dispersion. The morphology and other characteristics of the nanocomposite blends were investigated in terms of X‐ray diffraction, fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, tensile properties, scanning electron microscopy, and atomic force microscopy. The results indicate that the ester‐TPU(C10A)/PP/MA‐g‐PP exhibited better dispersion than other blend systems; abrasion resistance and water absorption resistance were also better for this system. POLYM. ENG. SCI., 50:1878–1886, 2010. © 2010 Society of Plastics Engineers     

Influence of varying fiber lengths on mechanical,thermal, and morphological properties of MA‐g‐PP compatibilized and chemically modified short pineapple leaf fiber reinforced polypropylene composites

Environmentally benign, low cost and abundantly available short pineapple leaf fibers (PALF), found mostly in the Tropical rain forest climates are ideal materials for manufacture of thermoplastic polymer‐matrix composites. Here, mechanical and thermal properties of composites of maleic anhydride grafted polypropylene (MA‐g‐PP) and chemically modified short PALF are studied as a function of different fiber lengths at 10 vol % fibers loading with fiber orientation in the longitudinal direction. The effects of fiber lengths and fiber loading on the morphological properties are assessed via observations by scanning electron microscopy. Fiber length of 6 mm oriented longitudinally at 10 vol % fibers loading in PP is the optimum and recommended composition, where 73% increase in impact properties, 37% increase in the flexural modulus, 33% increase in flexural strength, and 14% increase in vicat softening temperature are observed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Combined effect of organic phosphate sodium and nanoclay on the mechanical properties and crystallization behavior of isotactic polypropylene

Combined effect of α‐nucleating agent (NA) sodium 2,2′‐methylene‐bis(4,6‐di‐tert‐butylphenyl) phosphate (NA11) and nanoclay (NC) on the mechanical properties and crystallization behavior of isotactic polypropylene (iPP) was investigated by mechanical testing, wide‐angle X‐ray scattering (WAXD), differential scanning calorimetry (DSC), polarized optical microscopy (POM), and scanning electron microscopy (SEM). The mechanical testing results indicated that the separate addition of NA11 and NC only increased the stiffness of iPP while the combined addition of NA11, NC, and maleic anhydride grafted polypropylene (PP‐g‐MA) simultaneously improved stiffness and toughness of iPP. Compared to pure iPP, the tensile strength, the flexural modulus, and impact strength of iPP composites increased 9.7, 38.6, and 42.9%, respectively. The result indicated good synergistic effects of NC, NA11, and PP‐g‐MA in improving iPP mechanical properties. WAXD patterns revealed NA11, and NC only induced the α‐crystals of iPP. SEM micrograph showed that the PP‐g‐MA could effectively improve the dispersing of NC in iPP. Finally, the nonisothermal crystallization kinetics of neat iPP and PP nanocomposites was described by Caze method. The result indicated that the addition of NA overcame the shortcoming of low crystallization rate of NC nanocomposites and maintained the excellent mechanical properties, which is another highlight of the combined addition of NAs and nanoclay. Meanwhile, the result showed that nuclei formation and spherulite growth of iPP were affected by the presence of NA and nanoclay. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of maleic anhydride grafted polypropylene on the mechanical and morphological properties of chemically modified short‐pineapple‐leaf‐fiber‐reinforced polypropylene composites

With the rising cost of petroleum‐based fibers, the utilization of plant fibers in the manufacture of polymer–matrix composites is gaining importance worldwide. The scope of this study was to examine the perspective of the use of pineapple leaf fibers (PALFs) as reinforcements for polypropylene (PP). These fibers are environmentally friendly, low‐cost byproducts of pineapple cultivation and are readily available in the northeastern region of India. Here, both untreated and treated pineapple fibers were used. Maleic anhydride grafted polypropylene (MA‐g‐PP) was used as a compatibilizing agent. The polymer matrix of PP was used to prepare composite specimens with different volume fractions (5–20%) of fibers by the addition of 5% of MA‐g‐PP. These specimens were tested for their mechanical properties, and additional assessments were made via observations by scanning electron microscopy, thermogravimetric analysis, and IR spectroscopy. Increase in the impact behavior, flexural properties, and tensile moduli of the composites were noticed, and these were more appreciable in the treated fibers mixed with MA‐g‐PP. PALF in 10 vol % in PP mixed with MA‐g‐PP was the optimum and recommended composition, where the flexural properties were the maximum. The impact strength and the tensile modulus were also considerably high. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

An investigation for the effect of recycled matrix on the properties of textile waste cotton fiber reinforced (T‐FRP) composites

The main objective of this research is to study the effect of recycled low density polyethylene (r‐LDPE) matrix on the tensile, impact, and flexural properties of the novel textile waste cotton fiber reinforced (T‐FRP) composites. For this purpose, the T‐FRP composites were manufactured by using two different matrix types; namely, virgin LPDE (v‐LDPE) and r‐LDPE, with different waste cotton fiber content. All composites were compatibilized by maleic anhydride‐LDPE (MA‐LDPE) in order to increase the interfacial adhesion between fibers and matrices. Differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic mechanical analyzer studies were performed in order to characterize the materials. The results have shown that best tensile and flexural properties have been obtained from the composites with the content of 30 wt% cotton fiber, 5 wt% maleic anhydride‐LDPE, and 65 wt% recycled LDPE matrix. However, the impact properties of the composites were decreased drastically compared to the pure LDPE matrix. POLYM. COMPOS., 38:1231–1240, 2017. © 2015 Society of Plastics Engineers     

Isolation and characterization of betel nut leaf fiber: Its potential application in making composites

Betel nut leaf fiber (BNLF) is a new finding as cellulosic filler for polymer composites. Its main constituents are 75% α‐cellulose, 12% hemicelluloses, 10% lignin, and 3% others matter, viscosity average molecular weight 132,000 and degree of crystallinity 70%. In the present work, BNLF reinforced polypropylene (PP) composites were prepared using heat press molding method. 5–20 wt% short length fiber is taken for getting benefits of easy manufacturing and the fiber was chemically treated with NaOH, dicumyl peroxide (DCP), and maleic anhydride‐modified PP (MAPP) to promote the interfacial bond with PP. The extent of modification of fiber was assessed on the basis of morphology, bulk density, moisture absorption, thermal, and mechanical properties of untreated fiber, treated fiber, and their reinforcing PP composites. The tensile and flexural strength of composites increase with the increase of fiber loading up to 10 and 20 wt%, respectively. It was also observed that Young's modulus and flexural modulus increase with fiber loading. The thermal degradation behavior of resulting composites was investigated. Among the various treated fibers, MAPP‐treated fiber composite showed best interfacial interactions as well as mechanical and thermal properties. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Injection molding of long sisal fiber–reinforced polypropylene: Effects of compatibilizer concentration and viscosity on fiber adhesion and thermal degradation

A two‐step process was used to obtain long sisal fiber‐polypropylene (SF/PP)–reinforced thermoplastic composites, using maleic anhydride grafted polypropylene (MA‐g‐PP) as a compatibilizer. At a first stage, modified polypropylenes (mPP) were used for an extrusion impregnation process, for the preparation of composite pellets containing about 70 wt% of SF. SF/mPP pellets with a large aspect ratio were prepared by continuous extrusion impregnation of a continuous SF yarn, using a single screw extruder and an adequate impregnation die. The mPP used were MA‐g‐PP and regular polypropylene (PP), modified by reaction with different amounts of an organic peroxide. The composite pellets were thus dry blended with regular PP pellets in an injection machine hopper, and injection molded to obtain composite tensile specimens with a minimum quantity of modified polypropylene, minimum fiber breakage and thermal degradation, and excellent mechanical properties. It is shown that the fiber breakage is reduced to a minimum, even for recycled composites, due to the presence of the low‐viscosity polymer layer wetting the SF fibers. The bulk composite effective viscosity and the fiber breakage extent and thermal degradation during the injection‐molding step are found to be closely related. Blending with much less expensive mPP at the impregnation stage optimizes the amount of expensive MA‐g‐PP. POLYM. ENG. SCI., 45:613–621, 2005. © 2005 Society of Plastics Engineers     

Experimental investigation on the influence of the composition on the morphology and the mechanical properties of short glass fiber‐reinforced polypropylene nanocomposites

Polypropylene composites containing 0–5 wt% layered silicate and 0–30 wt% short glass fibers are prepared by melt compounding. To investigate the influence of different compositions on the mechanical properties of short glass fiber‐reinforced polypropylene nanocomposites, materials with various filler contents are prepared. At a glass fiber content of 10 wt% Young's modulus of the layered silicate‐containing composites decreases by around 30% compared to conventional glass fiber‐reinforced polypropylene. But at higher glass fiber loadings, an increasing modulus of up to 10% is observed. However, the addition of layered silicate results in large decreases of the tensile and the notched impact strength. A maleic anhydride‐grafted polypropylene enhances Young's modulus and the tensile strength. © 2012 Society of Plastics Engineers     

香蕉纤维的表面改性及其增强环氧树脂复合材料的性能研究

采用硅烷偶联剂(A-174)偶联、高锰酸钾接枝和乙酰化包覆等3种方法对香蕉纤维进行表面改性,制备了改性香蕉纤维增强环氧树脂复合材料,测试其拉伸、弯曲、压缩、冲击等力学性能。结果表明,偶联、接枝、包覆等表面改性均能明显改善香蕉纤维与基体树脂的相容性,提高复合材料的力学性能,其中偶联改性的效果最好。当改性香蕉纤维含量为10wt%时,与未改性的香蕉纤维比较,复合材料的拉伸强度、弯曲强度、压缩强度分别提高了1.8、1.0、2.6倍;随着纤维含量的增加,复合材料的力学性能明显提高。