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Dynamic mechanical analysis (DMA) is an essential procedure for characterizing the performance of composites and effectively simulate with the real-world applications. This research work aims to characterize the dynamic mechanical (DM) properties of sisal fiber reinforced polyethylene terephthalate (PET) composites as a factor of fiber content and fiber surface modification. The effect of elevated processing temperature (>260°C) on the thermal degradation of sisal fibers is also analyzed. To study the effect of sisal fiber loading, PET composite specimens; one with 25% by weight fraction of raw sisal fiber (w/w), abbreviated as 25% RSC and the other with 40% by weight fraction (w/w) of raw sisal fiber, hereafter abbreviated as 40% RSC, were prepared by injection molding. Similarly, to analyze the impact of fiber surface modifications, PET composite samples containing 40% by weight fraction (w/w) of alkali-treated sisal, hereafter abbreviated as (40% Al-SC), and 40% by weight fraction (w/w) of a combined alkali/acetylation-treated sisal, hereafter abbreviated as (40% Al-ASC), were prepared. It was found that the fiber volume fraction and fiber surface modifications affected the DM properties of the produced composites. The improved storage module and glass transition temperature (Tg) with minimized damping has been demonstrated by increasing fiber content. With the same 40% fiber content, the composites produced from modified fibers enhanced the storage modulus and Tg values. However, with increasing temperature, the storage modulus decreased, the loss modulus increased, and the damping factor increased with composites containing higher fiber content and surface modified fibers. This indicates the low thermal stability of the sisal fiber and the interface damage at elevated temperatures.

Hybrid composites with synthetic and natural fibers are a good choice in the field of composites, as they combine the good mechanical performance of synthetic fibers with the advantages of natural fibers. In this work, polymeric hybrid composites associating glass fiber and natural fibers were developed. Three hybrid composites were developed: sisal/glass, coir/glass and Luffa/glass. The composites are five-layer laminate, three layers of E-glass interspersed with two layers of natural fibers that can be sisal, coir, or Luffa sponge (Luffa Cylindrica). In addition to hybrid composites, a five-layer fiberglass composite was also manufactured. The composites were manufactured by compression molding technique using orthophthalic polyester resin as matrix. Tensile and flexural tests were performed to characterize the composites. Considering the three hybrid composites, the best behavior was observed for the sisal/glass composite, being a potential replacement for fiberglass. The order of performance was the same in the tensile and flexural tests, sisal/glass, coir/glass, and luffa/glass, in this order. In the specimen’s fracture analysis, for both tests, it was observed that the fracture was quite located with no damage in regions far from the fracture. This behavior indicates good adhesion between the layers of natural and synthetic fibers, despite the discrepancy of their properties.

This article aims to improve the sintering quality of the sisal fiber/poly-(ether sulfone) (PES) composite (SFPC) part fabricated via selective laser sintering (SLS). The sisal fiber and PES powders were proposed as the feedstock of the SFPC powder bed for SLS. An orthogonal experimental methodology with four levels and five factors was applied to optimize the process parameters for the single-layer sintering experiment. The mechanical properties and accurate dimensions of the sintered part were tested using a universal testing machine and Vernier caliper. The preheating temperature, scanning speed, and laser power were selected as influencing factors on the mechanical properties and accuracy dimensions of the SFPC part. Furthermore, the influence factors on the quality of the sintered part were studied and analyzed. Additionally, the synthesis weighted scoring method was used to determine the optimum parameters of the SLS part. The results showed that the optimal parameters (factors) were preheating temperature of 82°C, scanning speed of 2 m s−1, laser power of 14 W, and laser wavelength of 10.6 μm. Thus, the quality of SFPC part was significantly enhanced when the optimum parameters were applied in SLS process. This article provided the main reference value for the choice of the process parameters of the biomass composite.

The interest on poly(lactic acid) (PLA)/poly(methyl methacrylate) (PMMA) blends has increased during the last years due to their promising properties. The novelty of the current work focuses on the preparation and characterization of biocomposites based on PLA/PMMA matrix and NaOH-treated sisal fibers. The effect of the addition of treated sisal fibers on the physico-mechanical properties of high polylactide content composites was studied. For this purpose, PLA/PMMA blend (80/20 wt%) was prepared by melt-blending and reinforced with different fiber contents. Although composites showed interesting specific tensile properties, the estimated heat deflection temperature (HDT), that is, the maximum temperature at which a polymer system can be used as a rigid material, barely increased 4°C respect to unreinforced system. After the annealing process, the HDT of the unreinforced polymer blend increased around 25°C, whereas the composites showed an increase of at least 38°C. Nonetheless, the specific tensile strength of composite decreased approximately 48% because the adhesion between fiber and polymer matrix was damaged and cracks were formed during annealing process.

Natural fibers are increasingly being used as composite reinforcement for both thermoplastic and thermoset resin, mainly for automotive application. Due to their hydrophilic nature, natural fibers have certain limitations during composite manufacture especially owing to their poor resin wettability, weak fiber–polymer interface, high moisture absorption, and being affected by high temperature in case of thermoplastic resin. This work investigates the impact of sisal fiber modification techniques on moisture absorption, thermal, and mechanical properties of the fiber. Four sisal fiber samples were prepared; untreated, alkaline treated, acetylated, and a combined alkaline-treated/acetylation samples. The samples were evaluated for their hygroscopic nature, thermal stability, and tensile properties. It is found that acetylation resulted in a reduction of moisture absorption of sisal fiber as the acetylated and alkaline-treated/acetylated samples recorded a decrease of 42% and 28%, respectively. Alkaline treatment increased the absorbency owing to the removal of hemicellulose and lignin. The thermogravimetric result revealed that alkaline treatment improved the thermal stability as the alkali-treated and alkali-treated/acetylated samples showed improvement in thermal properties. The acetylated sample resulted in a significant reduction in tensile strength. But, the results from tensile tests of the alkaline-treated samples showed an insignificant decrease in tensile strength and improvement in the modulus for all treated samples. Fourier-transform infrared and scanning electron microscopic analysis were included in the study to supplement the results with structural and microstructural changes. The effect of those treatments on the sisal–PET composite properties was studied and will be submitted in part 2 of the study.

Reducing weight and stabilizing or upgrading the strength is more important. Automotive and related industries are making a progress to replace the conventional steel leaf spring to composites material made from glass fibre, natural fibres, and so on. In this study, woven E-glass fibre, woven sisal and hybridization of woven glass and sisal fibre have been selected as materials. The resin used in this study is epoxy (B-11(3101)) VHV and the hardener is (K-6(5205)). The mono leaf spring is fabricated using hand lay-up process, which tends to be simple and cost effective. The existing dimensions of a conventional Tata Ace leaf spring are selected for modelling and analysis. Stress and deflection is tested experimentally by flexural testing. The hardness of the composites is determined with the help of Rockwell and Brinell hardness testing machine and the values are correlated with each other. Leaf spring is modeled in CREO Parametric 2.0 and introduced in ANSYS 14.5 for the numerical analysis. The results suggest that the composites have reduced weight up to 75% in comparison with the conventional one. With reduced component weight and better performance achieved by composite material, the replacement of conventional material with that of the composite is efficient. The efficiency of a vehicle will improve with a reduced component cost when composite leaf spring is used.

An effective method was adopted to improve the thermo-mechanical properties of the epoxy composite by functionalization of the sisal fiber. Initially, a neat sisal fiber was acetylated with molar solution of acidic mixture (0.5:1 of HNO3:H2SO4) that removed the content of lignin and hemicellulose and increased the crystallinity of the sisal fiber. The acetylated sisal ( a-sisal) fiber was further treated with 3-aminpropyltriethoxy silane to graft the silanol moieties on sisal fiber. The functionalization of the sisal fiber with 3-aminpropyltriethoxy silane exhibits the strong interaction with epoxy, resulting in homogenous dispersion of the sisal fiber in epoxy. The composite possesses great enhancement in thermal and mechanical properties. The tensile strength in functionalized sisal epoxy composite ( CP-f-Sisal) was significantly enhanced up to 23% in comparison to non-functionalized sisal epoxy composite ( CP-n-Sisal) by adding 15 wt.% of the sisal fiber. In addition, the functionalized sisal epoxy composite ( CP-f-sisal) shows better thermal stability as compared to non-functionalized sisal epoxy composite ( CP-n-sisal). Similar results are attributed by investigating the kinetics of thermal stability parameters that include activation energy and integral procedure decomposition temperature.

In this article, a detailed systematic methodology to fabricate and characterize the diverse properties of soy protein and sisal fiber reinforced green composites has been presented. After fabrication by hand lay-up and solution casting method, these composites with varying sisal fiber weight percentages (0, 3, 4, 5, 6, 7 and 10) were put to various characterization tests. The surfaces of sisal fiber were treated with sodium hydroxide to enhance its interfacial bonding properties. The fabricated samples were examined on the basis of microstructural tests that included the scanning electron microscopy; followed by the mechanical (tensile) and physical (water absorption) tests. Finally, the thermal tests were performed that involved the thermogravimetric analysis, differential thermal analysis and dynamic mechanical analysis tests. The phytagel modified soy protein-based composite with 5 wt.% of sisal fiber content was confirmed to be the best of all compositions under this scrutiny, which was authenticated by the micro-structural and mechanical tests. To further enhance the mechanical, physical and thermal properties of fabricated composites, chitosan coating was applied on them.

The influence of hydrothermal carbonization of sisal fibers on the mechanical properties of composites based on recycled polypropylene matrices was investigated in this paper. The fibers were chara...

The incorporation of sisal fiber as reinforcement materials for polymers will be advantageous if it is synthesized and manufactured perfectly. In this study, surface modification using polymeric diphenylmethane di-isocyanate and gamma-aminopropyltriethoxysilane was applied for further amelioration of polypropylene–sisal bonding. Surface morphology, thermomechanical properties, thermal stability, and chemical bonding were investigated using scanning electron microscopy, dynamic mechanical analysis, thermogravimetric analysis, and Fourier transform infrared spectroscopy, respectively. A number of mathematical models were studied for predicting the effect of untreated and modified sisal fiber loadings on the mechanical properties of biocomposites. Polymeric diphenylmethane di-isocyanate showed a significant improvement on the thermal and mechanical properties of polypropylene biocomposites. Fourier transform infrared spectroscopy analysis of polypropylene–sisal biocomposite showed the formation of urethane group at 3333 cm−1 in the presence of polymeric diphenylmethane di-isocyanate. Glass transition temperature of polypropylene–sisal was slightly increased to 6.8°C by chemical modification with polymeric diphenylmethane di-isocyanate. Yield strength of polypropylene–sisal (30 wt%) was enhanced by more than 50% with polymeric diphenylmethane di-isocyanate chemical treatment. Halpin–Tsai and Nielsen theoretical mathematical models showed a good agreement with experimental results of polypropylene–untreated sisal and polypropylene–treated sisal, respectively.

In this study, the effects of fiber loading from 0 vol.% to 15 vol.% and the chemical treatments on the properties of the sisal fiber-reinforced sheet molding compounds were investigated. The chemical treatments were performed with alkali, γ-ammoniapropyl-triethoxy-silane (KH-550) and γ-methacryloxypropyl-trimethoxy-sliane (KH-570), respectively, to improve the interfacial adhesion between sisal fiber and the matrix (unsaturated polyester resin). The changes of surface morphology and sisal fiber functional groups were investigated by scanning electron microscopy and Fourier transform infrared spectroscopic analysis, respectively. Compared to the untreated sisal fiber-reinforced sheet molding compounds, the mechanical property of the treated sisal fiber-reinforced sheet molding compounds increased due to the interfacial enhancement between sisal fiber and the matrix, which could be observed through the scanning electron microscopy images of fracture surface. Moreover, the better interfacial adhesion was also assisted in water absorption resistance and the thermal stability of the treated sisal fiber-reinforced sheet molding compounds. In the chemical treatments, KH-570 treatment was proved to be an effective method to improve the interfacial adhesion between sisal fiber and the matrix.

In the current research enterprise, behavior of novel bio-composites incorporating Aloe Vera fibers in biopolymer matrix (polylactic acid) has been experimentally examined in comparison to Sisal fiber reinforced bio-composites. These bio-composites were melt blended using single screw extruder prior to injection molding. The effect of fiber weight fraction (10–20–30%) and fiber surface modification on mechanical behavior of developed bio-composites was investigated. Alkaline treatment using sodium hydroxide concentration of 5% was used for fiber surface modification. Both alkali treated and raw fibers were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscope. Thermal stability of the fibers improved after alkaline treatment. The mechanical characteristics of developed bio-composites exhibited an improvement with increasing fiber concentration. Alkaline treatment of fibers further improved the tensile, flexural and compressive properties of developed bio-composites, while their impact properties declined compared to raw fiber reinforced bio-composites. Moreover, from the results, it is evident that the characteristics of Aloe Vera fiber reinforced bio-composites are comparable to Sisal fiber reinforced bio-composites and the developed bio-composites have the potential to be used in various automotive, furniture and architectural applications.

In this paper, the effects of fiber shape, fiber distribution, fiber size and fiber hybridization on the tensile properties of short sisal fiber-reinforced polypropylene composites were studied by the generalized method of cells and laminate analogy approaches. It is found that the fiber distribution has a large effect on the axial Young’s modulus. The fiber shape and fiber size have stronger influences on the transverse Young’s modulus and axial Poisson’s ratio than the fiber distribution. The fiber type hybridization and fiber shape are shown to be important factors in affecting the axial shear modulus. Hybridization with glass fiber is found to be an efficient method of creating high-performance composites.

Sisal fiber (SF) reinforced recycled polypropylene biocomposites were prepared by melt blending technique. Biocomposites prepared with the incorporation of 40 wt% untreated sisal fiber loading showed a marginal improvement in mechanical properties as compared with matrix recycled polypropylene. SF surface was mercerized and maleic anhydride grafted polypropylene was used as a coupling agent for better fiber matrix interfacial bonding. Mercerized sisal fiber reinforced biocomposites prepared with compatibilizer (maleic anhydride grafted polypropylene) shows significant improvement in tensile and flexural strength. Damage tolerance of recycled polypropylene matrix and its biocomposites were evaluated in monotonic and cyclic tensile test. Untreated sisal fiber reinforced biocomposites prepared with maleic anhydride grafted polypropylene shows improvement in damage tolerance compared with untreated sisal fiber biocomposites. Impact fractured morphology of biocomposites revealed better interfacial bonding between fiber, maleic anhydride grafted polypropylene, and recycled polypropylene matrix.

The natural fiber reinforced biodegradable polymer composites were prepared with short sisal fiber as reinforcement in poly lactic acid (PLA) matrix. The sisal fiber is treated with 10% NaOH followed by H2O2. The composites were prepared with untreated and treated short sisal fibers at different weight proportions up to 25% in PLA matrix and investigated for mechanical and degradation properties. The results showed that the composite with treated fiber at 20% fiber loading has shown 30% and 8% higher tensile strength than neat PLA and untreated sisal/PLA composite, respectively. The flexural strength of treated sisal fiber composite at same weight fraction was 17% higher than that of plain PLA. The impact strength of composite with untreated fibers at 25% fiber loading was 107% high compared to that of neat PLA whereas the impact strength of treated sisal composite was reduced with increased fiber loading. The water absorption was high for untreated sisal/PLA composite compared to all other composites in the present study. Untreated sisal/PLA composite has high thermal degradation temperature compared to composite with treated fibers but lower than that of pure PLA. The enzymatic environment has increased the rate of degradation of composites. Surface morphology of tensile fractured and soil degraded surfaces of the composites were observed using scanning electron microscopy.

The effect of fiber twist on the tensile properties of single sisal fibers was investigated by single fiber tensile test. Four kinds of sisal yarns with four different levels of twist were made and the mechanical properties were investigated on both unimpregnated and resin-impregnated sisal yarns. A critical fiber twist level for unimpregnated sisal yarns was found beyond which the tensile properties started to decrease with the increasing of the level of fiber twist. However, for resin-impregnated sisal yarns, both tensile strength and modulus decreased with the increasing of the fiber twist level. In addition, the effect of fiber twist on both the tensile and flexural properties of unidirectional sisal yarn reinforced composites was studied. It was shown that lower twist level led to higher mechanical properties of its reinforced composites. Compared with the experimental results, Rao’s model proved to accurately calculate the Young’s modulus of fiber yarns with different levels of twist. Thus, the Young’s modulus of sisal yarn reinforced composites could be predicted by the rule of mixtures hereafter.

Application of natural fibers has attracted a great deal of attention among the composite research community in the past couple of decades. In this study, sisal fiber was utilized in fabrication of syntactic foam to improve the mechanical properties. Four sets of samples with different volume fractions of sisal fibers (0%, 1.5%, 2.5%, and 3.5%) were prepared. Viscoelastic properties of the samples were characterized with dynamic mechanical analysis. Storage and loss moduli, complex viscosity, and damping factor (tan δ) of syntactic foam samples were recorded. Dynamic mechanical analysis results showed improvement in storage and loss moduli in glassy region (30℃) up to 12% and 300%, respectively. In rubbery region (150℃), the storage modulus of sisal fiber syntactic foam was three orders of magnitude higher than plain ones. Decrease in the tan δ peak also indicated improved interfacial bonding by addition and increase in the content of sisal fibers. All these improvements in viscoelastic properties were achieved without any significant change in the density of syntactic foam.

Sisal fibers were pretreated by alkali and maleic anhydride, and then mixed with polypropylene to fabricate sisal fiber-reinforced composites by a self-made vane extruder based on elongational flow field. Maleic anhydride-grafted polypropylene was used as compatilizer to increase the fiber/matrix interactions. The influence of treatment on the fibers structure, the damage to fibers in processing, interfaces of composites and the mechanical properties of composites were investigated. It was observed that the surface of treated fibers was improved obviously compared with that of untreated fibers, which was believed to increase the adhesion between the fibers and matrix. However, the treated fibers were more likely to be damaged during processing. In comparison to unmodified system, the incorporation of treated fibers could significantly enhance the mechanical properties of composites, especially adding the compatilizer of maleic anhydride-grafted polypropylene. The flexural and impact strengths were maximum for the sisal fiber/polypropylene and maleic anhydride-grafted polypropylene composites, and its tensile strength was also improved significantly. The major contribution of this change should be that the morphology of fibers could be well preserved in elongational flow field, which based on the vane extruder showed a good application in fiber-reinforced composites.

In this study, properties of natural rubber (NR) were enhanced by adding sisal fiber, which is a tropical plant in Thailand. Sisal fiber/natural rubber composites were prepared by the incorporation of sisal fiber at various loadings into natural rubber. Natural rubber grafted with maleic anhydride (NR-g-MA) prepared in house and epoxidized natural rubber (ENR50) were used to enhance the compatibility between sisal fiber and natural rubber. With increasing fiber loading, tear strength and hardness of natural rubber composites increased while their scorch time, cure time, tensile strength, and elongation at break decreased. Moreover, interfacial adhesion between sisal fiber and natural rubber was enhanced with the addition of NR-g-MA and ENR50. In comparison, NR-g-MA provided more effective improvement in mechanical properties of natural rubber composites than ENR50. For NR-g-MA compatibilized natural rubber composite at fiber loading of 10 phr, its tensile strength, modulus at 100% strain, modulus at 300% strain, tear strength, and hardness were increased 43, 44, 53, 42, and 13%, respectively, comparing with that of uncompatibilized natural rubber composite.

Sisal fibers (SFs) were pretreated by heat treatment (HT). The SFs were mixed with a biodegradable material, polylactide (PLA), and the composites were prepared by hot press molding. The effects of the HT temperature and time on the mechanical properties of the composites were investigated, and the HT mechanism was studied by scanning electron microscopy and infrared, x-ray photoelectron, and nuclear magnetic resonance spectroscopies. The results show that an appropriate HT can remove strongly hydrophilic materials such as hemicelluloses from the fibers, and thus decrease their hydrophilicity, thereby improving the retting between the fibers and the matrix. This improves fiber–matrix interfacial adhesion, which can improve the mechanical properties of the composites. The HT also influences the fiber strength to some extent and affects the mechanical properties of composites.

In this study, polymer mortars manufactured with epoxy and unsaturated polyester resins reinforced with 1%, in weight, of sisal fibers were prepared. The fibers were chemically modified in order to improve their compatibility with inorganic aggregate, foundry sand, organic binder, and polymer resin. Sisal fibers were treated with 5% and 10% of NaOH and 20% of acetic acid diluted in an aqueous solution. Flexural and compressive tests were performed to evaluate the mechanical properties of such materials. Results showed that untreated sisal fibers improve the mechanical properties but treated fibers contribute to lower polymer mortars’ mechanical properties. An increase in stiffness is observed in all reinforced mortars due to fiber bridging.

Poly(lactic acid) (PLA) and polypropylene (PP) were comparatively investigated as matrices for injection-moulded composites containing small (1–3 wt%) amounts of short sisal fibre. The morphology, thermal and dynamic mechanical properties, as well as degradation characteristics were investigated. The scanning electron microscopy (SEM) micrographs of the composites show more intimate contact and better interaction between the fibres and PLA, compared to PP. This improved interaction was confirmed by the Fourier-transform infrared (FTIR) spectroscopy results which showed the presence of hydrogen bonding interaction between PLA and the fibres. The thermal stability (as determined through thermogravimetric analysis [TGA]) of both polymers increased with increasing fibre content, with a more significant improvement in the case of PP. The differential scanning calorimetry (DSC) results showed a significant influence of the fibres on the cold crystallization and melting behaviour of PLA, even at the low fibre contents of 1–3%. The influence of the fibres on the melting characteristics of the PP was negligible, but it had a significant influence on the nonisothermal crystallization temperature range. Both the storage and loss moduli of the PLA decreased with increasing fibre content below the glass transition of PLA, but the influence on the loss modulus was more significant. The dynamic mechanical analysis (DMA) results clearly show cold crystallization of PLA around 110°C, and the presence of fibres gave rise to higher modulus values between the cold crystallization and melting of the PLA. The presence of fibres also had an influence on the dynamic mechanical properties of PP. This article further describes basic biodegradation observations for the investigated samples.

The natural fiber composites based on kapok/sisal and its hybrid composites with polyester as resin matrix have been prepared and tested for mechanical properties. In this paper hardness and flexural properties of kapok/sisal composites were determined with reference to the fabrics content and varying the volume ratios of fabrics. The maximum strength in the properties determined is observed for the optimum fabric loadings. The effect of alkali treatment of fabrics on polyester composites reinforced with kapok/sisal fabrics was studied. Increasing the sisal fiber content resulted in a reduction in the hardness and flexural properties. The properties were found to increase with alkali treated fabrics used in composite. The properties of kapok/polyester composites are found to be better than those of kapok/sisal polyester composites.

Experiments are conducted to find out the tensile properties of short sun hemp, banana, and sisal fiber reinforced composites. Length of these natural fibers and fiber weight are varied and are impregnated in polyester resin to prepare tensile test specimen. Optimum values of fiber length and fiber weight ratios are found through experimental results. Analysis is done on these results.

The unsaturated polyester resin based sisal/glass hybrid composites were developed using the hand lay-up technique. Chemical resistance tests of these hybrid composites were performed in order to probe whether these composites can be used for making articles that are resistant to chemicals. The hybrid samples and the matrix have been tested for various acids, alkalis, and solvents. It is observed from the results that the developed hybrid composites are resistant to all the tested chemicals except carbon tetrachloride.

In order to evaluate the effect of processing conditions, composites of MaterBi-Y matrix with 15 wt% sisal fibers are obtained with different temperature profiles and speeds of rotation of the screw, using a twin-screw extruder. Three different temperature profiles are selected. The speeds of rotation are 25, 60, and 80 rpm. The samples are obtained by compression at 180°C and 700 MPa for 10 min. The mechanical properties of composites increase when the rotation speed changes from 25 to 60 rpm and then decreases. Fiber breakage increases with rotational speed, but aspect ratio increases too. Increased modulus with fiber aspect ratio is easily understood because longer fibers carry more tensile loads as a result of increase in transfer length. The decrease in the mechanical properties at a high rotational speed can be due to the degradation of the matrix. The impact properties increase when temperature increases. The decrease in impact properties at temperatures above 185°C can be due to the thermal decomposition of the material. Fil: Alvarez, Vera Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentina Fil: Ianonni, Antonio. Università di Perugia; Italia Fil: Kenny, José. Università di Perugia; Italia Fil: Vázquez, Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; Argentina

The variations of flexural strength and flexural modulus of unsaturated polyester-based sisal/glass hybrid composites with fiber content have been studied. The hybrid composites showed an increase in flexural properties with glass fiber loading. The effects of alkali treatment and silane treatment of fibers on the flexural properties of these sisal/glass hybrid composites have also been studied. No significant effect on the flexural properties has been observed by silane treatment but a small increase in these properties has been observed by alkali treatment.

This study investigates the permeability-porosity relationship for glass and natural fiber mats. The estimation of the permeability-porosity relationship for glass mats is not new and has been investigated before by several authors, but in the present paper the same relationship was discovered for natural fibers. The experimental permeability values were fitted by the Carman-Kozeny equation with two fitting parameters: the Kozeny constant and the exponent of the porosity. The obtained permeability for the natural fiber mats shows higher values than glass fiber mat.

The effect of surface treated sisal fiber on the mechanical, thermal, flammability, and morphological properties of sisal fiber (SF) reinforced recycled polypropylene (RPP) composites was investigated. The surface of sisal fiber was modified with different chemical reagent such as silane, glycidyl methacrylate (GMA), and O-hydroxybenzene diazonium chloride (OBDC) to improve the compatibility with the matrix polymer. The experimental results revealed an improvement in the tensile strength to 11%, 20%, and 31.36% and impact strength to 78.72%, 77%, and 81% for silane, GMA, and OBDC treated sisal fiber reinforced recycled Polypropylene (RPP/SF) composites, respectively, as compared to RPP. The thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), and heat deflection temperature (HDT) results revealed improved thermal stability as compared with RPP. The flammability behaviour of silane, GMA, and OBDC treated SF/RPP composites was studied by the horizontal burning rate by UL-94. The morphological analysis through scanning electron micrograph (SEM) supports improves surface interaction between fiber surface and polymer matrix.

This investigation deals with the effect of environmental influences on the mechanical properties of sisal fiber reinforced polymer composites. Dependencies between moisture, acid as well as lys attacks were determined and mechanical data of sisal fiber-polypropylene are evaluated. The results obtained led to the conclusion that the bending properties of sisal fiber-polypropylene composites are sensitive to environmental attack.