Reactive compatibilization and performance evaluation of miscanthus biofiber reinforced poly(hydroxybutyrate‐co‐hydroxyvalerate) biocomposites

Dicumyl peroxide (DCP) initiated reactive compatibilization of poly(hydroxybutyrate‐co‐hydroxyvalerate) (PHBV)/miscanthus fibers (70/30 wt %) based biocomposite was prepared in a twin screw extruder followed by injection molding. In the presence of DCP, both the flexural and the tensile strength of the PHBV/miscanthus composites were appreciably higher compared with PHBV/miscanthus composite without DCP as well as neat PHBV. The maximum tensile strength (29 MPa) and flexural strength (51 MPa) were observed in the PHBV/miscanthus composite with 0.7 phr DCP. The enhanced flexural and tensile strength of the PHBV/miscanthus/DCP composites are attributed to the improved interfacial adhesion by free radical initiator. Unlike flexural and tensile strength, the modulus of the PHBV/miscanthus/DCP composites was found to slightly lower than the PHBV/miscanthus composite. The modulus difference in the PHBV/miscanthus composite with and without DCP has good agreement with the observed crystallinity. However, the flexural and tensile modulus of all the prepared biocomposites was at least two fold higher than the neat PHBV. The storage modulus value of the PHBV/miscanthus and PHBV/miscanthus/DCP biocomposites follows similar trend like tensile and flexural modulus. The melting temperature and crystallization temperature of PHBV/DCP and PHBV/miscanthus/DCP samples were considerably lower compared with the neat PHBV and PHBV/miscanthus composites. The surface morphology revealed that the PHBV/miscanthus/DCP composites have good interface with less fiber pull‐outs compared with the corresponding counterpart without DCP. This suggests that the compatibility between the matrix and the fibers is enhanced after the addition of peroxide initiator. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44860.     

Formulation‐properties versatility of wood fiber biocomposites based on polylactide and polylactide/thermoplastic starch blends

This article discusses the interrelation between formulation, processing, and properties of biocomposites composed of a bioplastic reinforced with wood fibers. Polylactide (PLA) and polylactide/thermoplastic starch blends (PLA/TPS) were used as polymeric matrices. Two grades of PLA, an amorphous and a semicrystalline one, were studied. TPS content in the PLA/TPS blends was set at 30, 50, and 70 wt%. Two types of wood fiber were selected, a hardwood (HW) and a softwood (SW), to investigate the effect of the fiber type on the biocomposite properties. Finally, the impact of different additives on biocomposite properties was studied with the purpose to enhance the bioplastic/wood fiber adhesion and, therefore, the final mechanical performance. The biocomposites containing 30 wt% of wood fibers were obtained by twin‐screw extrusion. The properties of the biocomposites are described in terms of morphology, thermal, rheological, and mechanical properties. Furthermore, the biocomposites were tested for humidity and water absorption and biodegradability. An almost 100% increase in elastic modulus and 25% in tensile strength were observed for PLA/wood fiber biocomposite with the best compatibilization strategy used. The presence of the TPS in the biocomposites at 30 and 50 wt% maintained the tensile strength higher or at least equal as for the virgin PLA. These superior tensile results were due to the inherent affinity between the matrices and wood fibers improved by the addition of a combination of coupling and a branching agent. In addition to their outstanding mechanical performance, the biocomposites showed high biodegradation within 60 days. POLYM. ENG. SCI., 54:1325–1340, 2014. © Her Majesty the Queen in Right of Canada 2013 ¹      

Mechanical Properties of Poly(Butylene Succinate) Reinforced with Continuously Steam-Exploded Cotton Stalk Bast

Poly(butylene succinate) (PBS) was reinforced by cotton stalk bast fibers (CSBF), which had been pretreated by the continuous steam explosion method. The influence of water content in CSBF during the explosion and fiber content on the mechanical properties of CSBF/PBS biocomposites was investigated. The results showed that the incorporation of CSBF decreased the tensile and impact strength, while significantly enhanced the flexural strength, flexural modulus and tensile modulus. The mechanical properties of biocomposites reinforced by exploded fibers were much better than that of the biocomposites reinforced by non-exploded fibers. Biocomposites reinforced by fibers with 40 and 50 wt% water contents during the explosion had the best mechanical properties. The morphology of CSBF and biocomposites was evaluated by SEM, which demonstrated that fibers with 40 and 50 wt% water contents had better separation and rougher microsurfaces, indicating a better adhesion between PBS matrix and 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     

Mechanical properties and foaming behavior of cellulose fiber reinforced high‐density polyethylene composites

This article investigates the effects of fiber length and maleated polymers on the mechanical properties and foaming behavior of cellulose fiber reinforced high‐density polyethylene composites. The results from the mechanical tests suggested that long fibers provided higher flexural and impact properties than short fibers. In addition, the maleated high‐density polyethylene increased flexural strength significantly, while the maleated thermoplastic elastormers increased notched Izod impact strength dramatically. On the other hand, the results from the extrusion foaming indicated that the composites with long and short fibers demonstrated similar cell morphology, i.e., a similar average cell size and cell size distribution. However, the addition of maleated high‐density polyethylene caused an increase of the average cell size and cell size distribution in the composites. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Polyolefin composites with natural fibers and wood‐modification of the fiber/filler–matrix interaction

Numerous strategies to improve the fiber–matrix interaction in natural fiber composites (NFCs) and wood polymer composites (WPCs) have been proposed and investigated. We have reviewed literature on polyolefin‐based NFCs and WPCs to get an overview of the current state of the art of compatibilization methods. Those are classified in two categories here, namely fiber‐based strategies and matrix‐based strategies. Although this issue has been covered by several reviews before, as yet no work exists that is focused on polyolefin‐based NFCs and WPCs. Furthermore, a ranking of the compatibilization methods based on their effects on material properties such as tensile/flexural strength and modulus, impact strength and water absorption, allows for an assessment of the efficiency of the various methods. As to the fiber‐based strategies, silanes, maleated polyolefins (MA‐POs), mercerization and acetylation are most thoroughly investigated. Silanes are most effective judged by achievable material property improvements, allowing for increases in tensile and flexural strength of more than 100%. Among the matrix‐based strategies, MA‐POs and isocyanates are most prominent in the literature. The first class enables the more significant material improvements, with reported increases of tensile and flexural strength of 132% and 85%, respectively. While strengths can be enhanced by many compatibilization methods, moduli, and impact strength (notched in particular) are in most cases improved to a lesser degree or even reduced. Especially, the last point calls for further attention, because impact strength is still a weak point of NFCs and WPCs. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013     

Mechanical and thermal properties of waste silk fiber‐reinforced poly(butylene succinate) biocomposites

This article reports the mechanical and thermal properties of poly(butylene succinate) (PBS) biocomposites reinforced with industrially available waste silk fibers, fabricated with varying fiber contents and lengths. The result indicates that use of waste silk fibers may be a potential as reinforcement for effectively improving the static and dynamic mechanical properties of a biodegradable polymer matrix resin, depending on the waste silk fiber content and length in the present biocomposite system. The “as‐separated” waste silk/PBS biocomposites showed the maximum tensile and flexural properties at a fiber loading of 40 wt %, and the “chopped” waste silk/PBS biocomposites showed the optimal strength and modulus with waste silk fibers of 12.7 mm length. The chopped waste silk fibers play a more contributing role in improving the mechanical properties of waste silk/PBS biocomposites than the as‐separated waste silk fibers at a fixed fiber loading. Above the glass transition temperature, the storage modulus of waste silk/PBS biocomposites was significantly greater than that of PBS resin, especially in the higher temperature region. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4972–4980, 2006     

Development and characterization of flax fiber reinforced biocomposite using flaxseed oil‐based bio‐resin

In this study, acrylated epoxidized flaxseed oil (AEFO) resin is synthesized from flaxseed oil, and flax fiber reinforced AEFO biocomposites is produced via a vacuum‐assisted resin transfer molding technique. Different amounts of flax fiber and styrene are added to the resin to improve its mechanical and physical properties. Both flax fiber and styrene improve the mechanical properties of these biocomposites, but the flexural strength decreases with an increase in styrene content. The mass increase during water absorption testing is less than 1.5% (w/w) for all of the AEFO‐based biocomposites. The density of the AEFO resin is 1.166 g/cm³, which increases to 1.191 g/cm³ when reinforced with 10% (w/w) flax fiber. The flax fiber reinforced AEFO‐based biocomposites have a maximum tensile strength of 31.4 ± 1.2 MPa and Young's modulus of 520 ± 31 MPa. These biocomposites also have a maximum flexural strength of 64.5 ± 2.3 MPa and a flexural modulus of 2.98 ± 0.12 GPa. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41807.     

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.     

Influence of fly ash cenospheres on performance of coir fiber‐reinforced recycled high‐density polyethylene biocomposites

Recycled high‐density polyethylene (RHDPE)/coir fiber (CF)‐reinforced biocomposites were fabricated using melt blending technique in a twin‐screw extruder and the test specimens were prepared in an automatic injection molding machine. Variation in mechanical properties, crystallization behavior, water absorption, and thermal stability with the addition of fly ash cenospheres (FACS) in RHDPE/CF composites were investigated. It was observed that the tensile modulus, flexural strength, flexural modulus, and hardness properties of RHDPE increase with an increase in fiber loading from 10 to 30 wt %. Composites prepared using 30 wt % CF and 1 wt % MA‐g‐HDPE exhibited optimum mechanical performance with an increase in tensile modulus to 217%, flexural strength to 30%, flexural modulus to 97%, and hardness to 27% when compared with the RHDPE matrix. Addition of FACS results in a significant increase in the flexural modulus and hardness of the RHDPE/CF composites. Dynamic mechanical analysis tests of the RHDPE/CF/FACS biocomposites in presence of MA‐g‐HDPE revealed an increase in storage (E′) and loss (E″) modulus with reduction in damping factor (tan δ), confirming a strong influence between the fiber/FACS and MA‐g‐HDPE in the RHDPE matrix. Differential scanning calorimetry, thermogravimetric analysis thermograms also showed improved thermal properties in the composites when compared with RHDPE matrix. The main motivation of this study was to prepare a value added and low‐cost composite material with optimum properties from consumer and industrial wastes as matrix and filler. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42237.     

Nonwoven polylactic acid and flax biocomposites

Flax fiber‐reinforced polylactic acid (PLA) biocomposites were made using a new technique incorporating an air‐laying nonwoven process. Flax and PLA fibers were blended and converted to fiber webs in the air‐laying process. Composite prepregs were then made from the fiber webs. The prepregs were finally converted to composites by compression molding. The relationship between the main process variables and the properties of the biocomposite was investigated. It was found that with increasing flax content, the mechanical properties increased. The maximum tensile strength of 80.3 MPa, flexural strength of 138.5 MPa, tensile modulus of 9.9 GPa and flexural modulus of 7.9 GPa were achieved. As the molding temperature and molding time increased, the mechanical properties decreased. The thermal and morphological properties of the biocomposites were also studied. The appropriate processing parameters for the biocomposites were established for different fiber contents. POLYM. COMPOS., 34:1611–1619, 2013. © 2013 Society of Plastics Engineers     

Regenerated cellulose fibers as impact modifier in long jute fiber reinforced polypropylene composites: Effect on mechanical properties,morphology, and fiber breakage

Polypropylene/jute fiber (PP‐J) composites with various concentrations of viscose fibers (VF) as impact modifiers and maleated polypropylene (MAPP) as a compatibilizer have been studied. The composite materials were manufactured using direct long fiber thermoplastic (D‐LFT) extrusion and compression molding. The effect of fiber length, after the extrusion process, on composites mechanical performance and toughness was investigated. The results showed that the incorporation of soft and tough VF on the PP‐J improved the energy absorption of the composites. The higher impact strength was found with the addition of 10 wt % of the impact modifier, but the increased concentration of the impact modifier affected the tensile and flexural properties negatively. Similarly, HDT values were reduced with addition of viscose fibers whereas the addition of 2 wt % of maleated polypropylene significantly improved the overall composite properties. The microscopic analysis clearly demonstrated longer fiber pullouts on the optimized impact modified composite. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41301.     

Preparation and properties of biocomposites based on jute fibers and blend of plasticized starch and poly(β‐hydroxybutyrate)

In this work, preparation and properties of biocomposites based on jute fibers and blend of plasticized starch and poly(β‐hydroxybutyrate) (PHB) have been investigated. Different amounts of glycerol and aliphatic polyesters (PHB) have been added to native starch to obtain a processable biodegradable matrix. In the same way natural jute fibers up to 30 wt % loading were added to improve the mechanical and thermal stability of the material. Tensile mechanical, thermal, and thermomecahnical analyses have been performed to characterize the ensuing materials. Significant enhancement in the mechanical properties and water sensitivity were noted by the addition of 8 wt % PHB. The fibers incorporation into the biopolymer matrix brings about an increase in both the mechanical strength and modulus as much higher as the fibers loading is important. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effective mechanical properties of polyvinylalcohol biocomposites with reinforcement of date palm leaf fibers

Polyvinylalcohol/date palm leaf fiber (PVA/DPL) biocomposites were prepared by the melt mixing fabrication technique with various proportions of fibers. DPL fibers were chemically modified with the purpose of improving the dispersion and better compatibility with PVA matrix. Different chemical processes of modification were adopted and the tensile strengths of both treated and untreated fibers were compared. It was noticed that the tensile strength of acrylic acid treated fiber was optimum in comparison to other methods. The interaction of DPL fibers with PVA matrix were studied by Fourier transforms infrared spectroscopy (FTIR). Field emission scanning electron microscope (FESEM) was used to study the morphology of biocomposites. The tensile strength, Young's modulus, elongation at break, flexural strength, and impact strength of PVA/DPL biocomposites were investigated and compared with that of virgin PVA matrix. It was found that the above properties were first increased with fiber loading and then decreased. The optimum properties were obtained at 28 wt% of DPL fiber. The storage modulus and tan delta values of PVA/DPL biocomposites were analyzed. The thermal properties of biocomposites were also studied through the results of thermogravimetric (TGA). POLYM. COMPOS., 34:959–966, 2013. © 2013 Society of Plastics Engineers     

苎麻纤维增强磷建筑石膏复合材料耐水性能和力学性能研究

通过吸水率、软化系数、抗折强度和抗压强度试验,并结合傅里叶红外光谱和扫描电子显微镜测试,探究不同长度和掺量的苎麻纤维对苎麻纤维增强磷建筑石膏复合材料耐水性能和力学性能的影响。研究结果表明,掺入适量苎麻纤维可改善苎麻纤维增强磷建筑石膏复合材料的耐水性能和力学性能,以及提高复合材料的延性。掺入0.5%(体积分数,下同)的10 mm苎麻纤维时,复合材料的软化系数达到最大,较空白组提高20.0%。苎麻纤维的掺入能有效提高复合材料的抗折强度,28 d时,掺入1.5%的10 mm苎麻纤维试样较空白组抗折强度提高39.5%。掺入小于20 mm的苎麻纤维会降低复合材料的抗压强度,掺入不超过1.5%的30 mm苎麻纤维可提高复合材料的抗压强度,28 d时,掺入1.5%的30 mm苎麻纤维试样较空白组抗压强度提高10.1%。苎麻纤维在复合材料基体内会发生水解,随龄期的增长水解程度加重,表面逐渐粗糙。     

Biocomposites based on renewable resource: Acetylated and non acetylated cellulose cardboard coated with polyhydroxybutyrate

Renewable resource based bilayer films were prepared from polyhydroxybutyrate film (PHB) and cellulose cardboard via compression molding, containing 5, 10, 15 and 20 wt% of PHB.The effects of PHB contents on moisture absorption, water absorption and water vapor permeation of films were investigated. All biocomposites showed improved permeation properties. As of 15% of PHB, water permeation, equilibrium moisture content and polarity showed a marked drop. It is therefore assumed that the hydrophobic PHB covered up the cellulose cardboard and formed a continuous layer. The water-polymer interactions in materials are critical to the prediction of their behavior in applications where they are exposed to water or humid environment.The elastic modulus (E), tensile strength (σ) and strain at break (?) of two-layer biocomposites depend on the PHB content. Improved uniaxial tensile behaviour was obtained in composites with more than 15% of PHB.In order to improve the adhesion between the cellulose and the PHB, the cellulose cardboard was acetylated. The percentage of moisture absorbed is less than the composites without treatment, due to the better adhesion between the PHB and the cellulose cardboard.This work showed the studies carried out to obtain and study a new biodegradable bilayer material with the needed amount of PHB to improve the barrier and the mechanical properties of cellulose cardboard. It was demonstrated that two-layer PHB-cellulose films exhibited suitable barrier and mechanical performance for packaging applications, taking advantage of the good properties of both materials. Use PHB coatings should provide an outlet for replace Tetra Pak packaging.     

Effects of fiber extraction,morphology, and surface modification on the mechanical properties and water absorption of bamboo fibers‐unsaturated polyester composites

Bamboo fibers reinforced unsaturated polyester (UPE) composites were prepared by compression molding. Effects of fiber extraction, morphology, and chemical modification on the mechanical properties and water absorption of the bamboo fibers‐UPE composites were investigated. Results showed that the unidirectional original bamboo fibers resulting composites demonstrated the highest tensile strength, flexural strength, and flexural modulus; the 30–40 mesh bamboo particles resulting composites had the lowest tensile strength and flexural strength, but had comparable flexural modulus with that of chemical pulp fibers. The treatment of bamboo fibers with 1,6‐diisocyanatohexane (DIH) and 2‐hydroxyethyl acrylate (HEA) significantly increased the tensile strength, flexural strength and flexural modulus, and water resistance of the resulting composites. Fourier Transform Infrared and X‐ray photoelectron spectroscopy analyses showed that DIH and HEA were covalently bonded onto bamboo fibers. Scanning electron microscopic images of the fractured surfaces of the composites showed that the treatment of bamboo fibers greatly improved the interfacial adhesion between the fibers and UPE resins. The water absorption kinetics of the composites was also investigated; and the results showed that the water absorption of the composites fitted Fickian behavior well. POLYM. COMPOS., 37:1612–1619, 2016. © 2014 Society of Plastics Engineers     

Development of biodegradable composites with treated and compatibilized lignocellulosic fibers

The aliphatic polyester Bionolle 3020 was combined with lignocellulosic fibers, namely, flax, hemp, and wood, to produce biodegradable composite materials. The effect of two fiber surface treatments, acetylation and propionylation, and the addition of maleic anhydride (MA)‐grafted Bionolle 3001 as a compatibilizer on the fiber/matrix interfacial adhesion was studied. The compatibilizer was synthesized through a MA grafting reaction in the presence of dicumyl peroxide as an initiator. The composites' mechanical properties, water absorption, fracture morphology (scanning electron microscopy), and biodegradation were evaluated. Both the fiber treatments and the compatibilizer incorporation significantly improved the composites' tensile strength, whereas an important reduction in the water absorption was found with the addition of treated fibers. Moreover, fiber incorporation into the matrix increased its biodegradation rate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4703–4710, 2006     

The morphology and degradation behavior of electrospun poly(3‐hydroxybutyrate)/Magnetite and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/Magnetite composites

Electrospinning of biodegradable poly(3‐hydroxybutyrate) (PHB)/magnetite and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV)/magnetite composites in 2,2,2‐trifluoroethanol (TFE) and chloroform are investigated to develop nonwoven nanofibrous structure. Ultrafine PHB/magnetite fibers are obtained and the resulting fiber diameters are in the range of 690–710 nm and 8.0–8.4 µm for the polymer dissolved in TFE and chloroform. The surface of PHB composites fiber fabricated in chloroform contains porous structures, which are not observed for the sample of PHB composites fiber dissolved in TFE. The fiber diameters for PHBV5/magnetite composites are in the range of 500–540 nm and 2.3–2.5 µm, depending on the use of TFE and chloroform. The average diameters of PHBV5/magnetite composite fibers are smaller than those of PHB/magnetite composites fiber. All electrospun PHB/magnetite and composite fibers are superparamagnetic. The degradation behaviors of PHB/magnetite and PHBV5/magnetite composite fibers were investigated using Caldimonas manganoxidans. For the fabricated composite fibers, it is found that the degradation rate increased with the increasing loading of magnetite nanoparticles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41070.     

An efficient way to improve the mechanical properties of polypropylene/short glass fiber composites

Enhancement of tensile strength, impact strength, and flexural strength of polypropylene/short glass fiber composites by treating the glass fibers with coupling agent, mixing with maleated polypropylene (MPP) for compatibilization and adhesion, and with nucleating agent for improvement of polypropylene crystallization was studied. The results showed that both the silane coupling agent and MPP enhance tensile strength, impact strength, and flexural strength. In the absence of MPP, the effect of silane coupling agent on the mechanical properties of the composites decreases in the following order: alkyl trimethoxy silane (WD‐10) > γ‐methacryloxypropyl trimethoxysilane (WD‐70) > N‐(β‐aminoethyl)‐γ‐aminopropyl trimethoxysilane (WD‐52), whereas in the presence of MPP, the order changes as follows: WD‐70 > WD‐10 > WD‐52. When the glass fibers were treated with WD‐52, 4,4‐diamino‐diphenylmethane bismaleimide (BMI) can further enhance the mechanical properties of the composite. The three kinds of strengths increase with MPP amount to maximum values at 5% MPP. As a nucleating agent, adipic acid is better than disodium phthalate in improving the mechanical properties, except for the notched impact strength. Wide‐angle X‐ray diffraction showed that the adipic acid is an α‐type nucleating agent, whereas disodium phthalate is a β‐type nucleating agent. Blending with styrene–butadiene rubber can somewhat improve the notched impact strength of the composites, but severely lowers the tensile strength and bending strength. Scanning electron micrographs of the broken surface of the composite showed greater interfacial adhesion between the glass fibers and polypropylene in the modified composite than that without modification. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1414–1420, 2005