Fiber-matrix Interfacial Adhesion Research Articles

Mechanical and Tribological Properties of Carbon Fiber Reinforced POM Composite Filled With Maleamidic Acid Treated Carbon Nanotube

ABSTRACTIn order to attain improved mechanical properties of the carbon fiber (CF) reinforced polyoxymethylene (POM) composite, maleamidic acid treated carbon nanotube (CNT) was deposited on carbon fiber. The mechanical properties of composites have been investigated. The tensile strength values of the treated CF/POM composites at all CNT mixing ratios are found to be higher than that of untreated one. The surface morphologies of the fractured surfaces of the composites were recorded using scanning electron microscopy (SEM) to gain information about the fiber–matrix interfacial adhesion in the composites. The friction coefficient of all the CF/POM/CNT composites decrease as the load increases from 10 to 20 N under the same sliding speed of 1000 r/min. XPS results showed that the formation of C–O, C=O, and O–C=O based species give rise to chemical bonds of the CF and the POM.

Recycled Low Density Polyethylene Reinforced with Deverra tortuosa Vegetable Fibers

In this work, natural fibers extracted from the medicinal aromatic plant Deverra tortuosa, with different sizes (S1 = 2 mm and S2 = 500 μm), were incorporated into recycled low density polyethylene (rLDPE) to produce sustainable biocomposites. Compounding was performed with different fiber concentrations (0 to 30% wt.) via twin-screw extrusion followed by injection molding. Based on the samples obtained, a comprehensive series of characterization was conducted, encompassing morphological and mechanical (flexural, tensile, hardness, and impact) properties. Additionally, thermal properties were assessed via differential scanning calorimetry (DSC), while Fourier transform infrared spectroscopy (FTIR) was used to elucidate potential chemical interactions and changes with processing. Across the range of conditions investigated, substantial improvements were observed in the rLDPE properties, in particular for the tensile modulus (23% for S1 and 104% for S2), flexural modulus (47% for S1 and 61% for S2), and flexural strength (31% for S1 and 65% for S2). Nevertheless, the tensile strength decreased (15% for S1 and 46% for S2) due to poor fiber–matrix interfacial adhesion. These preliminary results can be used for further development in sustainable packaging materials.

A study of mechanical properties and performance of bamboo fiber/polymer composites

In recent years, bamboo seems to have attracted the attention of researchers due to its advantages over synthetic polymers including being renewable, environmentally friendly, and fully biodegradable. Bamboo fibers at (9, 13, and 18 wt%) are filled with epoxy resin and the effects of mixing the bamboo fibers on mechanical properties were studied. In this paper, the tensile properties and performance of natural bamboo fiber powder-reinforced epoxy polymer matrix-based composites were investigated at three different curing temperatures ranging from T26 °C, T38 °C, and T50 °C. The results showed that the tensile strength and Young's modulus of the bamboo fiber/epoxy composites increased at T26 °C are 41.6 MPa and 2.84 GPa, respectively, for particle size 0.52 μm at a weight loading of 13 %. The increase in tensile strength is due to the excellent fiber matrix interface adhesion. However, it was found that the samples tested under T26 °C for bamboo fiber-reinforced epoxy composites acquired better tensile strength than those tested under the high temperatures of T38 °C and T50 °C. According to the analysis of the flexural characteristics of bamboo particle/epoxy composites, the composite with 1.5 μm particle size has the highest flexural strength at 13 wt% weight loading, measuring 105 MPa. The composite with a 1.5 μm particle size at 18 wt% loading records the maximum impact strength of, 5593 J/m2. This work provides a new approach for the development of lightweight and high-strength composite from natural fiber and polymer.

Fully bio‐based flax/furan versus carbon/glass epoxy composites: Scope and limitations in terms of fire and physico‐mechanical performances

AbstractFire and mechanical performances of a bio‐based flax/furan resin composite are evaluated and, in order to assess their commercial potential, compared with those of conventional carbon/glass fiber‐reinforced composites. Fire retardant (FR) variants of flax/furan were obtained by adding FRs to the resin and using (i) flax or (ii) FR‐treated flax fabrics. With (i), the fire hazard of the composite could be reduced to minimum, without detrimental effect on the mechanical properties. However, use of FR‐flax fabric (ii) led to impairment of mechanical properties. This indicated that for optimized fire and mechanical properties, use of a FR in the resin matrix suffices; there is no advantage in using a FR‐treated flax fabric. Natural aging of the samples for 10 years followed by water aging indicated that water absorption in flax/furan composites was much higher than in comparable carbon/epoxy composites. While there was evidence of released acidic components such as acetic acid, oxalic acid, and so forth, in flax/furan composites, mainly from oxidative degradation of furan resin, there was no evidence of leaching of FR additives from the matrix. However, FR treatment of flax fabric affected the fiber–matrix interfacial adhesion, leading to considerable water absorption during aging and disintegration of the reinforcement.Highlights Furan resins are naturally fire retardant, burn only under forced combustion. FR flax/furan composites obtained by adding FRs to the resin or the flax fabric. FR treatment of the flax impairs mechanical properties and water tolerance. FRs in the resin neither affect mechanical properties nor leach out in water.

Silane treatment for sisal fibers to improve the degradation resistance and interface with cement matrix

In order to improve the degradation resistance of sisal fibers in the alkaline cement matrix and enhance the fiber-matrix interface adhesion, silane treatment on fiber was studied. Four kinds of commonly used silane coupling agents were selected to modify the sisal fibers via the simple dip-coating method. Contact angle, water retention, and semi-immersion tests were performed on the sisal fibers to determine the influence of silane treatment on their hydrophilicity and barrier property. The interfacial bonding between the sisal fibers and cement matrix was studied by a self-designed fiber pull-out test. Furthermore, the degradation of sisal fibers embedded in cement matrix and sisal fiber reinforced cementitious composites (SFRCC) was evaluated based on the changes of mechanical properties with accelerated aging. The results indicate that silane treatment is an efficient approach to mitigate the degradation of SFRCC.

Mechanical and Thermal Characterization of Bamboo and Interlaminar Hybrid Bamboo/Synthetic Fibre-Reinforced Epoxy Composites.

The main objective of this study was to investigate the mechanical and thermal properties of bamboo, as well as interlaminar hybrid composites reinforced with both bamboo and synthetic fibres in an epoxy matrix. Bamboo and glass, aramid, and carbon bidirectional fabrics were used with a bi-component epoxy matrix to fabricate the composite materials using the vacuum bagging process. The synthetic fabrics were placed on the outer layers, while the bamboo fabrics were used as the core of the hybrid composites. The developed composites were characterized and compared in terms of morphological, physical, and mechanical properties. Further, thermogravimetric (TGA) analysis was used to measure and compare the degradation temperature of the composites studied. Finally, a Scanning Electron Microscopy (SEM) analysis was performed in order to examine the fracture surfaces of the specimens tested. It was found that the fibre hybridization technique significantly improved the general mechanical properties. TGA analysis showed an increase in the thermal stability of the composites obtained by incorporating the synthetic fibres, confirming the effect of hybridization and efficient fibre matrix interfacial adhesion. The results from this work showed that the use of synthetic fibre reinforcements can help to significantly improve the mechanical and thermal properties of bamboo fibre-reinforced composites.

Performance analysis of fiber-reinforced polypropylene composite laminates under quasi-static and super-sonic shock loading conditions for impact application

In the present research, glass and basalt fiber-reinforced polypropylene composites’ behaviour in quasi-static and dynamic conditions is studied. Composites were fabricated by vacuum assisted Compression molding method. Composites failure under quasi-static tension and compressive conditions was studied along with its failure behaviour under low-velocity impact and super-sonic shock loading under dynamic conditions. The study results showed that basalt fiber-reinforced polypropylene (Basalt/PP) composite’s tensile and compressive strength is higher than glass fiber-reinforced polypropylene (Glass/PP). The Basalt/PP showed no penetration against low velocity impact (LVI) with negligible deformations till 50 J. However, the Glass/PP perforated at 50 J with various failure patterns occurring at back side. The fiber-matrix interface adhesion plays an important role in super-sonic shock loading by absorbing shock wave energy due to ductile nature of polypropylene and the two composites absorbed energy via matrix and fibers failure, no brittle failure of laminates occurred under shock loading.

The mechanical effect of functionalization in laminated composite material

PurposeThis study aims to systematically compare the effect of increasing fiber–matrix interface adhesion and matrix toughness in layered composite materials.Design/methodology/approachSilane ((3-glycidyloxypropyl) trimethoxysilane) was applied to strengthen the fiber–matrix interface connection in e-glass/epoxy laminated composite material. Using a cationic surfactant, 0.1% multi-walled carbon nanotubes (CNTs) were added to the matrix in two different ways, by with and without chemical functionalization using the vacuum infusion method.FindingsIn the results obtained from the three-point bending test specimens, it was determined that the synergistic effect of silane application and non-functionalized CNT in the matrix was higher in terms of flexural modulus and strength values.Practical implicationsThe functionalization of multi-walled CNT did not give the expected results because of reasons such as viscosity increase and agglomeration in the matrix.Originality/valueIn this study, a simple model for normalization and prediction purposes was developed, which allows the determination of the flexural modulus and un-notched flexural strength values from one test result of the notched specimen. A systematic comparison was performed by varying each parameter in the composite material.

Characterization of chemically treated waste wood fiber and its potential application in cementitious composites

In recent years, the utilization of various fibers in cementitious composites gained remarkable popularity worldwide. Unlike well-known fibers, this study focused on examining the incorporation of waste wood fiber (WWF) assorted from construction and demolition sites into the cementitious matrix. In the first stage of the study, alkali-treatment of the WWF was carried out with different concentrations of sodium hydroxide (NaOH) solution (i.e., 1.0 M, 2.0 M, 2.5 M, 5.0 M, 10.0 M) and treatment durations (i.e., 2 h, 4 h, 6 h, 12 h) to eliminate impurities and enhance fiber properties and fiber-matrix compatibility through surface treatment. To investigate alkali-treatment efficiency, microstructural analyses were conducted on the untreated and alkali-treated WWFs by Scanning Electron Microscopy and Fourier Transform Infrared Spectrophotometer measurements. Afterward, physical and mechanical performance assessments were conducted by water absorption test, compressive and four-point bending tests on the WWF-incorporated cementitious composites to monitor the compatibility behaviour of the WWF-matrix interface. Microstructural examinations showed that after the alkali treatment, impurities (i.e., painting, hemicellulose, lignin, etc.) on the WWF surface were successfully removed; however, higher alkali concentrations (beyond 5.0 M) and longer treatment duration (after 6 h) lead to deterioration, fragmentation, and a more heterogeneous structure due to the degradation of long cellulosic chains of WWF. Four-point bending test results showed that the flexural strength capacity of 2.5M-2 h-WWF-composite was 7.9 MPa, which was higher than untreated WWF-composite and plain mortar by 34.7% and 39.8%, respectively. Furthermore, the 2.5M-2 h treated WWF composite had the highest compressive strength of 46.3 MPa, which was higher than plain mortar, and the untreated WWF composite by 6.4% and 21.5%, respectively. The elimination of impurities such as painting, lignin, hemicellulose, and other inorganic compounds at the optimal alkali treatment concentration and time increases the WWF surface area and strengthens the fiber-matrix interface adhesion, resulting in a stronger matrix-WWF interface connection and an increase in load-carrying capability. The study's findings are believed to encourage the usage of alkali-treated WWF in cementitious matrix with improved mechanical performance and high waste upcycling.

Appropriate software model for evaluating the effect of untreated and treated sisal fibre with different gauge length and strain rates for geotextile applications

Geotextiles are commonly used as reinforcement in building, engineering and road laying applications. The sisal fibre is one of the natural fibres which is used to reinforce soil and prevent damage. This sisal fibre is specifically helpful to fill gaps between roads to improve soil structure, and prevent soil erosion but allows the water to drain off. This paper is concerned with the study of the effect of gauge length on the strength and elongation of sisal fibres in untreated and treated states with sodium hydroxide at different concentrations and duration of treatment. The reason for applying sodium hydroxide treatment on sisal fibre is to remove the impurities from it and to improve the inter fibre adhesion with resin for producing a composite. The effective reinforcement of composites with plant fibres depends on the moisture content and the fibre matrix interfacial adhesion. Treatment with alkali improves the performance of fibres when they are used as composites. Also, the effect of strain rate on the strength and elongation of sisal in untreated and treated states has been investigated. The Weibull modelling software model has been used in many studies to quantify the degree of variability in the fibres. This paper deals with the application of an appropriate software model such as the Weibull distribution model for quantifying the variability in strength and elongation at different gauge lengths varied from 10 mm to 100 mm and also varied the strain rate from 10 mm/min to 500 mm/min. In addition to the Weibull distribution model, air plasma treatment and SEM (Scanning Electron Microscope) analysis on sisal fibre were also carried out in this paper. The result shows that the sisal fibre is more suitable for geotextile applications.

Amine-caged ZrO2@GO multilayer core-shell hybrids in epoxy matrix for enhancing interfacial adhesion of carbon fiber composites

Amine-caged ZrO2@GO multilayer core-shell hybrids were successfully fabricated and incorporated into epoxy matrix for the first time for enhancing the carbon fiber-matrix interfacial adhesion. Composites with the addition of this hybrid exhibit the highest interfacial shear strength, with 48.4%, 26.7% and 19.5% augmentations over those of untreated, ZrO2 and GO reinforced composites. The strengthening mechanism is by increasing the wettability of resin to the fiber. Moreover, the outer amino-rich cage facilitates the covalent and π-π stacking interactions at interphase, thus transferring stress effectively. Mutual slippage of middle flexible GO could dissipate energy under shear force. The inner rigid ZrO2 is apt to restrict the initiation and propagation of cracks. The three synergies work together to contribute the obvious increment in interfacial adhesion. The innovative utilization of such multilayer core-shell structured hybrids as polymer modifier may provide a design strategy for obtaining composites with ideal interfacial bonding.

Eucalyptus Bark Residue Application for Poly(Vinyl Chloride) Composite Production: Influence of Fiber Size and Content

Background: Brazil is the world’s largest producer of short fiber cellulose, generating large amounts of eucalyptus bark residue (EBR). Aiming to obtain composites known as wood plastic composites (WPC), the effect of ground EBR addition to a poly(vinyl chloride) (PVC) matrix was studied, considering different granulometries and matrix/load proportions. The influence of fiber content addition and particle size range was analyzed in terms of mechanical and thermal properties of the PVC-EBR fiber composites obtained. Finally, by comparing these properties with those reported in the literature, the viability of EBR application as filler/reinforcement in a WPC with PVC matrix was verified. Objective: The main objective of the present study was to evaluated the influence of EBR fiber size and content in the WPC with PVC matrix, aiming to reduce the costs and improve its mechanical and physical properties. Materials and Methods: The processing method for prepared the composites were two-roll milling and subsequent hot pressing. The residue was characterized via chemical and thermogravimetric analyses, scanning electron microscopy (SEM), and aspect ratio determination. Composite evaluation involved density, tensile and flexural tests, impact resistance, heat deflection temperature (HDT), moisture absorption, and SEM of tensile fractured specimens. Results: Tensile and flexural moduli were improved with fiber addition attaining 46% and 58% increases, respectively, with better results for smaller particle size fibers; impact resistance and elongation at break, however, were reduced, attaining 48% and 5% of the control sample’s properties. SEM images reveal fiber detachment and pull-out due to their low matrix adhesion. EBR fibers cause more void formation due to low interface adhesion, which results in poor stress transference from the matrix to the fiber, in addition to EBR acting as stress concentrators in the PVC matrix; therefore, impact fracture occurs with lower energy levels. Discussion: Regions with fiber detachment and pullout from the matrix are visible, clearly demonstrating the low adhesion properties of the phases and also in accordance with the observed decrease in mechanical properties for both fibers. SEM images indicate that fibers can be considered foreign particles inside the PVC matrix, acting as stress concentrators. Also, since fibers have diameters larger than the voids caused by crazing, planar density is reduced in the direction perpendicular to chain stretching leading to low strain at break values. Composites of fiber with finer particle showed fewer voids, possibly indicating a more efficient adhesion for fibers. This could be due to a higher penetration of polymeric chains in the rugosity of finer fibers, leading to higher values of tensile strength. Conclusion: The addition of EBR content increased especially flexural and tensile moduli whilst elongation at break and impact resistance are reduced. The reduction in tensile strength due to poor fiber-matrix interfacial adhesion, though significant, allowed the use of composites with higher fiber additions. The use of EBR is coherent with the concept of circular economy. Thus, higher fiber additions relate directly to money savings since this residue costs less than PVC, and also this is an environmentally correct destination for this residue since WPC is long-term usable allowing for recycling.

Development and characterization of surface functionalized hierarchical carbon fiber reinforced hybrid polypropylene composites

Light-weight hybrid composites of relevant industrial applications were prepared using surface functionalized hierarchical carbon fibers ( f-CF), silane treated hollow glass microspheres (HGM), and a blend of polypropylene (PP) and maleic anhydride-grafted-styrene ethylene butylene styrene as the base polymer matrix. The f-CF were prepared by coating amine functionalized carbon nanotubes onto silane treated CF using an ultrasonic assisted electrophoretic deposition technique to improve fiber-matrix interfacial adhesion. For hybrid composition of 20 wt.% f-CF and 10 wt.% HGM, the tensile strength and modulus improved by ∼141 and ∼536% over neat PP while flexural strength and modulus increased by ∼118% and ∼583% respectively. Impact strength of 11.06 kJ/m2 was obtained and uniform dispersion and distribution of f-CF and HGMs was observed in Scanning electron microscope (SEM) images. Desirable reduction in density and melt viscosity along with improvement in composite stiffness were observed due to addition of HGM filler. Compared to PP, the crystallization temperature increased by ∼12°C while a maximum decrease of ∼5°C in melting temperature was obtained for the hybrid composites. Crystallinity of the hybrid composites decreased with an evident β crystal formation brought in by the nucleation.

A review on the enhancement of composite’s interface properties through biological treatment of natural fibre/lignocellulosic material

Natural fibre or lignocellulosic fibres have aroused the attention of scientists in the polymer industry, given their eco-friendly, low density, and biodegradability. Nevertheless, the major obstacle to wide commercial applications is the incompatibility between polar natural plant fibres with non-polar polymer matrix due to different chemical constitutions. Therefore, surface treatment of natural fibres before they are implemented to prepare fibre-reinforced composites is considered. Chemical and physical treatments are not preferred as it involves hazardous chemicals and high energy consumption. This review article provides an overview of various environmentally friendly approaches, such as introducing bacterial nanocellulose, pre-treatment with bacterial cellulase, fungal treatment, and enzymatic treatments aimed to treat natural fibres. The implications of working mechanisms on the characteristics of fibre itself and polymer composites with reinforcement are reviewed. The application of treated fibres reinforced composites and comparison of biological treatment with other treatments are discussed in this article. It is evidenced that fibre that undergoes biological modifications facilitates better fibre-matrix interfacial adhesion, has stronger mechanical bonding with the matrix, along with the reduction of water uptake of the composites.

Effect of Fiber Shape on the Tribological, Mechanical, and Morphological Behaviors of Sisal Fiber-Reinforced Resin-Based Friction Materials: Helical, Undulated, and Straight Shapes.

In this paper, we aim to evaluate the tribological, mechanical, and morphological performance of resin-based friction composites reinforced by sisal fibers with different shapes, namely helical, undulated, and straight shapes. The experimental results show that the shape of the sisal fibers exerts a significant effect on the impact property of the composite materials but no obvious influence on the density and hardness. The friction composite containing the helical-shaped sisal fibers exhibits the best overall tribological behaviors, with a relatively low fade (9.26%), high recovery (98.65%), and good wear resistance (2.061 × 10−7 cm3∙N−1∙m−1) compared with the other two composites containing undulated-shaped fibers and straight-shaped fibers. The impact fracture surfaces and worn surfaces of the composite materials were inspected by scanning electron microscopy, and we demonstrate that adding helical-shaped sisal fibers into the polymer composites provides an enhanced fiber–matrix interface adhesion condition and reduces the extent of fiber debonding and pullout, effectively facilitating the presence of more secondary plateaus on the friction surface, which are responsible for the enhanced tribological and mechanical properties. The outcome of this study reveals that sisal fibers with a helical shape could be a promising candidate as a reinforcement material for resin-based brake friction composite applications.

Characterization of interfacial strength in natural fibre – polyolefin composites at different temperatures

ABSTRACT It is often suggested that optimization of the fibre-matrix interfacial adhesion is essential to improve the mechanical performance of natural fibre reinforced thermoplastic compounds. The use of such composites in many applications often requires characterisation of performance over a range of temperatures. This paper presents a study on the measurements of the interfacial adhesion of coir fibre with various polyolefin matrices at room temperature. We then present a novel adaptation of a dynamical mechanical analyser to enable the measurement of interfacial shear strength over the temperature range of −40°C to 120°C. Results from these measurements are presented and discussed in terms of the relationship of apparent IFSS to residual thermal stresses in such thermoplastic composites.

Effect of layering pattern and fiber hybridization on viscoelastic properties of PALF/COIR hybrid epoxy composites

To design and develop a hybrid biocomposite material for structural applications, it becomes necessary to determine the optimum fibers layering pattern. Therefore, in this research work, the different layered hybrid biocomposite boards i.e. bilayer pineapple/coir (P/C), trilayer (PCP, CPC), and intimately mixed (IM) were developed and characterized for viscoelastic properties. The composites were made by hand lay-up method, keeping the volume ratio of PALF and COIR 1:1 and the total fiber volume fraction is 0.40 volume of composite. Dynamic mechanical thermal analysis test was employed to characterize the viscoelastic behavior in terms of storage modulus, loss modulus, loss damping factor, and the glass transition temperature. Amongst all the different layered hybrid composites, the trilayer CPC has lowest value (0.635) of effectiveness coefficient with highest stiffness and activation energy (40.54 kJ/mole). It confirms the better fiber-matrix interaction at the interfacial region. The glass transition temperature of CF-EP and PF-EP was increased by 8.74% and 13.15% respectively by the synergistic hybridization of cellulosic fibers. The PCP layered composite possesses lowest value of phase transition energy (9.17 kJ/mole) and this was because of the poor fiber-matrix interfacial adhesion.

In-situ Microfibrillar Recycled PET/Glass Fiber/PP Hybrid Thermoplastic Composites

Hybrid composites of in-situ microfibrillar recycled polyethylene terephthalate (rPET)/glass fiber (GF)/polypropylene (PP) were developed as an economical and environmentally friendly alternative to glass fiber reinforced thermoplastic PP composites. The effect of replacing glass fibers with in-situ formed polymer microfibrils on mechanical and viscoelastic properties of the composites was investigated with tensile, flexural, and dynamic mechanical tests. Characterization results showed that mechanical and viscoelastic performance of 34% glass fiber reinforced PP can be obtained with 24% glass fiber, 10% microfibrillar rPET composites. Compatibilization effect of the maleic anhydride grafted PP (MA-g-PP) was studied using Fourier transform infrared (FTIR) spectroscopy. The scanning electron microscopy (SEM) images confirmed the formation of the rPET microfibrils in the hybrid matrix. Besides, composites with MA-g-PP compatibilizers showed significantly improved fiber-matrix interfacial adhesion on the SEM images.

Animal fiber characterization and fiber loading effect on mechanical behaviors of sheep wool fiber reinforced polyester composites

ABSTRACT This study presents animal fiber characterization and the influence of various fiber loadings on mechanical properties of sheep hair fiber-reinforced polymer (SHFRP) composites. The sheep hair fibers (SHF) characterization was carried out using X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM) and non-contact surface roughness machine. The functional group and chemical bond were analyzed using FTIR techniques. The crystallinity index and thermal stability of the SHF were characterized, using XRD and TGA techniques, respectively. The composites were fabricated using a compression molding technique and a varying weight percentage of 20, 30 and 40 fiber. The composite plates were cut into test samples according to ASTM standard methods for their mechanical (tensile, flexural and impact) behaviors to be extensively analyzed. The surface morphology of the fractured samples was examined with aid of an SEM. From the results obtained, it was evident that the SHFRP composite recorded a significantly increased tensile strength property when fiber loading was increased from 20 to 40 wt%. The optimum 40 wt% SHFRP composite sample recorded better flexural and impact strength, when compared with other counterparts. This was attributed to a better fiber-matrix interfacial adhesion, as established fromSEM micrographs.

Study of the Compatibilization Effect of Different Reactive Agents in PHB/Natural Fiber-Based Composites

Fiber–matrix interfacial adhesion is one of the key factors governing the final properties of natural fiber-based polymer composites. In this work, four extrusion reactive agents were tested as potential compatibilizers in polyhydroxylbutyrate (PHB)/cellulose composites: dicumyl peroxide (DCP), hexamethylene diisocyanate (HMDI), resorcinol diglycidyl ether (RDGE), and triglycidyl isocyanurate (TGIC). The influence of the fibers and the different reactive agents on the mechanical properties, physical aging, and crystallization behavior were assessed. To evaluate the compatibilization effectiveness of each reactive agent, highly purified commercial cellulose fibers (TC90) were used as reference filler. Then, the influence of fiber purity on the compatibilization effect of the reactive agent HMDI was evaluated using untreated (U_RH) and chemically purified (T_RH) rice husk fibers, comparing the results with the ones using TC90 fibers. The results show that reactive agents interact with the polymer matrix at different levels, but all compositions showed a drastic embrittlement due to the aging of PHB. No clear compatibilization effect was found using DCP, RDGE, or TGIC reactive agents. On the other hand, the fiber–polymer interfacial adhesion was enhanced with HMDI. The purity of the fiber played an important role in the effectiveness of HMDI as a compatibilizer, since composites with highly purified fibers showed the greatest improvements in tensile strength and the most favorable morphology. None of the reactive agents negatively affected the compostability of PHB. Finally, thermoformed trays with good mold reproducibility were successfully obtained for PHB/T_RH/HMDI composition.