Fiber Surface Treatment Research Articles

Improving the surface treatment of Mannii rattan fibers for the reinforcement of composite materials using Weibull analysis

Improving the surface treatment of Mannii rattan fibers for the reinforcement of composite materials using Weibull analysis

Interlaminar fracture properties of UV and plasma‐treated glass fiber epoxy composites

AbstractDespite the low density and high specific strength properties, the fiber‐reinforced composites are characterized by a relatively low interlaminar fracture toughness and their ultimate properties are strongly affected by the fiber matrix adhesion. This study aims to investigate the influence of fiber surface treatments, such as UV and atmospheric plasma, and of the interfacial shear strength, on the flexural properties and Mode I interlaminar fracture toughness of glass fiber epoxy composites. The vacuum‐assisted resin infusion technique is used for the composite fabrication. Scanning Electron Microscopy analysis is used to observe and to explain the changes in the morphology of the fibers after surface treatment. Remarkably, the results showed an overall reduction in the mechanical properties. The interfacial shear strength values of the UV and plasma‐treated samples were reduced by 34.9% and 49.5% respectively. The flexural strength was reduced by 7.9% and 5.9% respectively. The Mode I fracture toughness values for the UV and plasma‐treated samples were also reduced by 49.8% and 62.2% respectively.Highlights UV and plasma treatments were performed on glass fibers to improve performance. Push‐out tests were carried out to evaluate fiber/matrix adhesion. An aerospace grade epoxy resin curing in thermal press‐clave was used. Mechanical tests related Interfacial Shear Strength to composites performance.

Effect of fiber surface treatment with silane coupling agents and carbon nanotubes on mechanical properties of carbon fiber reinforced polyamide 6 composites

Effect of fiber surface treatment with silane coupling agents and carbon nanotubes on mechanical properties of carbon fiber reinforced polyamide 6 composites

Use of commercial synthetic filament waste to reinforce biobased poly(butylene succinate) with the aid of compatibilizers

Since poly(butylene succinate) (PBS) has low rigidity for engineering application, this research attempted to reinforce PBS with poly(ethylene terephthalate) (PET) and polyamide-6 (nylon6) filaments with the reservation of polymer toughness. Filaments were chopped to be short fibers (length of 2 mm to 4 mm) and melt compounded with PBS pellets in the weight ratio of 1 wt%, 5 wt%, and 7 wt% using a twin-screw extruder that the temperature profile was set high enough for melting only PBS matrix. Two types of compatibilizers; hexamethylene diisocyanate (HMDI) or hexamethylene diamine (HMDA) of 0.05 wt% were used to treat fiber surface. It was found that tensile modulus of PBS increased with respect to fiber concentration, which untreated PET fibers provided higher tensile modulus about 2% to 7%. Surface treatment of fibers with either HMDI or HMDA increased rigidity of the composites, while elongation at break and impact strength were also improved with respect to fiber concentration. Also, shifting in glass transition temperature of PBS by DMA indicated improved interfacial interaction, which HMDA treatment gave the best benefit for mechanical properties. Number-average molecular weight of HMDI-treated composites was closed to extruded PBS, however, those of HMDA-treated composites were reduced dramatically implying chain scission highly occurred. SEM micrographs revealed good interfacial adhesion obtained after fiber treatment. Crystallization of PBS studied by XRD showed that the crystal form was not affected by the compatibilizer.

Effect of matrix modification and fiber surface treatment on the properties of basalt fiber reinforced polypropylene composites

With a focus on sustainable natural fiber reinforced polypropylene composites in varied industries like automotive and aerospace, this study investigates the impact of matrix modification and surface treatment of basalt fibers on the thermomechanical properties of basalt fiber reinforced heterophasic polypropylene composites. Polypropylene matrix modification was achieved by adding maleic anhydride grafted polypropylene (PP-g-MA), resulting in composites that exhibited a 133 % improvement in the tensile strength and 256 % improvement in the tensile modulus at 30 % fiber weight compared to neat polypropylene. The short basalt fibers underwent a silane treatment; However, the thermal treatment used to strip the default manufacturer's sizing resulted in a fluffy fibres texture, which led to agglomeration and feeding issues during processing. Although the silane treatment helped establish a better fiber-matrix interphase, no significant improvement in tensile strength was observed. However, the tensile modulus saw a 343 % improvement at 30 % fiber weight as compared to neat polypropylene. Resizing short basalt fibers following fiber recovery at the end-of-life stage of the composite would be challenging due to the fluffy nature of the fibers. Therefore, any fiber treatment should be done at the initial fiber manufacturing stage, and surface treatment at later stages requires detailed study.

Effect of wettability on the void formation during liquid infusion into fibers

AbstractLiquid composite molding (LCM) is a promising option for low‐cost manufacturing of high‐performance composites compared to traditional prepreg‐autoclave methods. Void formation may be the most significant roadblock to such adaptation of LCM. In this article, the hypothesis that higher wettability, that is, lower contact angles of liquid on solids, would lead to lower void content for LCM is tested. First, a theory that calculates the energy required to form a bubble with varying contact angles is formulated by considering interfacial energy differences of a system with and without it. To experimentally prove this hypothesis, six different carbon fiber reinforcement samples were prepared each with a different fiber surface treatment. The wettability from the surface treatments was evaluated with contact angle measurements based on capillary rise between two fiber yarns. Void formation in situ during infusion was evaluated by a series of 1D infusion experiments using the same six surface modifications. Of the six samples, the reinforcements coated with fluorinated alkane and aminosilane showed the highest wettability and lowest void content, confirming that a lower contact angle can reduce the formation of voids during the infusion process.Highlights Higher wettability was correlated with less bubble (void) formation. Theoretical model and LCM experimental confirmation. Various surface modifications of carbon fibers tested. Potential application: enhancement of properties from LCM manufactured parts.

Response of short jute fibre preform based epoxy composites subjected to low-velocity impact loadings

This work aimed to investigate the low velocity impact behaviour of short jute fibre non-woven preform epoxy matrix composites experimentally. Dry fibre preforms were developed using an optimised process and a laboratory made preforming device. The effects of alkali and poly vinyl alcohol (PVA binder) treatments on impact performances of jute composites were investigated and compared at 3 J and 6 J impact energy levels. To identify the failure modes of tested composites, the X-ray µCT tomography was employed. The results demonstrated that the developed untreated short jute fibre preform reinforced composites absorbed a higher impact energy, when they were compared to treated (alkali or PVA binder) composites. For untreated composites, maximum impact forces at 3 J and 6 J energies, were found as ⁓2478 N and ⁓2319 N, respectively; for the PVA treatment these values were measured as ⁓2457 N and ⁓2216 N, while, at same energy levels, alkali treated composites showed the lowest values as ⁓1683 N and ⁓1440 N, respectively. Untreated jute fibre contains natural matrices such as hemicellulose, lignin and waxes, which ensured a positive response to absorb more energy upon impact loading. In contrast, the alkali treatment facilitates a highly fibre packed composite structure, which accelerated the impact crack propagation in tested composites, resulting in lower resistance to impact energy. Although, PVA treated composites showed reduced impact properties compared to untreated composites due to the PVA polymer brittleness on the treated fibre surface during the impact incidents, this treatment demonstrated better impact responses over the alkali treatment. The application of PVA binder on alkali-treated fibres provided an extra support to fibres and a better fibre/matrix interface and hence, this combined treatment demonstrated a slightly better impact resistance (⁓2027 N and ⁓1874 N impact forces at 3 J and 6 J respectively) compared to only alkali treated fibre composites. The SEM fracture images and the X-ray µCT damage analysis revealed different impact damage modes, which supported the observed impact results. The obtained results from this investigation could be helpful for using short jute fibre composites in various load demanding applications where impact incidents are likely to be happened.

Bond behavior between recycled macro fibers and ultra-high-performance concrete matrix: Tests and property characterization

A green and cost-efficient ultra-high-performance concrete (UHPC) has been proposed using discrete macro fibers recycled from waste glass fiber reinforced polymer (GFRP). The tensile properties of such composites are significantly affected by the macro fiber/UHPC bond properties. However, there is very little work characterizing the bond properties of the macro fiber/UHPC interface. Furthermore. lack of study focused on the methods for macro fiber surface treatment and their effects on macro fiber/UHPC interfacial bonding. Therefore, the present study first carried out pullout tests in two series consisting of 128 pullout specimens. Series 1 aimed to characterize the bond behavior of the macro fiber/UHPC interface, while Series 2 aimed to investigate the effect of surface-modifying agents on macro fiber/UHPC interfacial bonding. The results demonstrated that the bond strength increased from 19.3 to 20.9 MPa when the embedded length of the 8 mm-wide fiber increased from 5 to 10 mm. The modification of neutral Nano SiO2 (NNS) enhanced the bond strength by up to 20.5 %, while alkaline Nano SiO2 (ANS) and silane coupling agent (SCA) showed a negative effect on bond strength. Then, the shear-lag theory was utilized for predicting the pull force-slip curves of the fibers embedded in UHPC, and then the bond parameters of the interfaces were obtained through an inverse analysis. A good agreement is exhibited with integral absolute error (IAE) from 4.5 % to 10.5 % between predicted results and test results.

Influence of CO2 laser surface treatment of basalt fibers on the mechanical properties of epoxy/basalt composites

AbstractIn fiber reinforced composite materials, the interfacial strength between the fibers and the matrix plays a key role in controlling the stress transfer and damage mechanisms of the composite. In this study, CO2 laser surface treatment of the fibers was investigated as a potential sustainable substitute for conventional chemical treatments, that can be costly and have negative environmental effects. The influence of the laser treatment on basalt fiber fabric was comprehensively investigated. The fibers were subjected to different laser power levels and characterized from a morphological and mechanical point of view. From optical and scanning electron microscopy, it was observed that the treated fibers manifested increased surface roughness along with spots of fused and bonded fibers. Individual treated fibers exhibited improved tensile properties with increased values of scale parameter (by about 21%) in the case of a laser power equal to 1.04 W/mm2, and no substantial changes in Young's modulus. The treated fibers were subsequently used in the preparation of epoxy‐based microcomposites, and microdebonding tests revealed an increase in the interfacial shear strength (IFSS) up to 8%. Therefore, this work proved that a laser surface treatment of basalt fibers is a valid alternative to conventional fiber surface modification to enhance the mechanical compatibility between fibers and matrix, and therefore to improve the mechanical performances of basalt fiber composites.Highlights Failure in composites due to weak interfacial adhesion with epoxy. CO2 laser treatment of basalt fibers to enhance interfacial adhesion. Treated fibers exhibit improved tensile properties. Treated fibers manifested improved interfacial shear strength (IFSS, +8%).

A review of the emerging approaches for developing multi‐scale filler‐reinforced epoxy nanocomposites with enhanced impact performance

AbstractFiber‐reinforced polymer composites (FRPCs) are utilized for myriad applications owing to their exceptional characteristics like high specific strength and stiffness. However, the low‐to‐moderate impact strength of these materials is a major constraint restricting their usage in fields requiring high‐impact performance. To ensure the reliable performance of FRPCs throughout the intended life span, a combination of good static mechanical properties and high impact resistance is crucial. Recent advancements in this field have yielded a breakthrough by developing novel materials that overcome this limitation. This groundbreaking achievement was realized by processing epoxy‐based GFRPs containing a synergistic blend of surface‐modified nano‐clay and compatibilized polymeric fiber micro‐reinforcement. This review provides an overview of advancements in the development of FRPCs, starting from the single‐filler to multi‐scale filler‐reinforced materials. The review elaborates on the effect of reinforcement of various thermoplastic fibers (polyethylene, para‐aramid, and spandex) on the mechanical performance of FRPCs. The necessity of filler compatibilization to enhance interfacial bonding constituents is also discussed. It can be concluded that the choice of surface treatment for a given thermoplastic fiber is governed by its chemical composition, the functional groups to be added on its surface through a specific compatibilization treatment, and the chemical nature of other constituents of the composite system with which the treated fiber surface interacts. Further, the greater the elasticity and ductility of the reinforced thermoplastic fiber, the higher the impact strength of the resulting epoxy‐based GFRPs. Finally, the review brings forth the potential opportunities for future research in this area.Highlights Discussed recent advancements in epoxy‐based GFRPs with multi‐scale filler reinforcement. Multi‐scale filler‐reinforced epoxy‐based GFRPs have myriad applications in aviation, automobile, marine, sports, etc. Nano‐/micro‐fillers in their pristine state degrade the mechanical performance of epoxy‐based GFRPs. Filler compatibilization is essential for achieving superior mechanical performance in epoxy‐based GFRPs. Reinforcing compatibilized soft/ductile thermoplastic fibers resulted in a notable increase in impact strength while maintaining tensile properties.

The ablation threshold and incubation effect in picosecond laser surface treatment of CFRP

The ablation threshold of carbon fiber is a critical parameter to consider in the laser surface treatment of carbon fiber reinforced polymers (CFRP), as it is necessary to design process parameters based on the threshold fluence to ensure process quality and efficiency. The incubation effect is a key factor influencing the ablation threshold, and a more rational incubation model contributes to a more accurate prediction of the ablation threshold. The conventional incubation model describes the regular decrease of the ablation threshold with an increasing pulse number. However, experimental findings show that the time interval of pulses is also a significant factor affecting the ablation and incubation process. In this study, the conventional incubation model was improved by comprehensively considering the time interval and space interval of pulses, which shows better prediction ability of ablation threshold under different parameter sets. The temperature history of CFRP under picosecond laser irradiation was calculated to support the rationality of the optimized incubation model. In addition, the laser-induced periodic surface structures (LIPSS) and the ablation of carbon fibers and resin were investigated based on the ablation threshold.

Study on the picosecond laser surface treatment and tribological properties of 3D woven carbon fiber reinforced carbon matrix (Cf/C) composites

Carbon fiber reinforced carbon matrix (Cf/C) composites have demonstrated great significance in many fields, especially in aircraft and automobiles as brake materials. The surface physical/chemical states of Cf/C composites significantly affect their tribological properties. Although ultrafast laser machining technology has been proven to be an effective method for modifying material surfaces, there are some issues concerning the ultrafast laser surface treatment of Cf/C composites and the adjustment of their tribological properties by laser treatment. Here, the 3D woven Cf/C composites were treated with an infrared picosecond laser. The effects of machining parameters on the surface microscopic morphology, chemical compositions, and graphitization degree were investigated. The experiment results indicated that the ultrafast laser treatment could eliminate surface defects, improve surface quality, and reduce the porosity of the Cf/C composites due to photothermal-mechanical ablation. More importantly, the laser-induced photothermal effects led to a graphitization transformation of Cf/C composites from a disordered turbostratic structure into an ordered graphite structure with an increased graphitization degree. The abundant micro-nano structures and the graphitization transformation on the Cf/C composite surface contributed to forming a complete and dense friction film on the Cf/C composites. Therefore, the laser-treated Cf/C composites showed lower COF, higher wear rate, and more stable tribological properties. This study demonstrated a method to adjust the tribological properties of Cf/C composites by ultrafast laser surface treatment, which showed great significance for the surface treatment and tribological property enhancement of Cf/C composites.

Study on the physicochemical properties of human hair fiber‐reinforced modified epoxidized soybean oil‐based composites

This paper investigates the effect of fiber surface treatment on various properties of hair fiber reinforced composites. Human hair fiber reinforced modified epoxidized soybean oil based composites were prepared by compression molding technique. Acid treatment of hair fibers was carried out by using three different concentrations of HCl solution (0.25%, 0.75%, and 1%, respectively) in order to achieve improvement in adhesion between the fiber and the matrix. Epoxidized soybean oil was modified using methacrylic acid and methacrylic anhydride to form methacrylic anhydride modified epoxidized soybean oil. Rosin acid derivative (a rigid comonomer) was prepared and used as a crosslinker. Fourier‐transform infrared spectroscopy was carried out to study the interaction among the components of the composites. Various properties, namely, mechanical, thermal, flame resistance, and chemical resistance were checked. Scanning electron microscopy of the fractured surface of the composites was carried out to examine the morphologies. Hair fibers treated with 0.75% of HCl showed maximum improvement in all the properties and could be employed as reinforcement in various composites to be used for structural applications.

Effect of Graphene Oxide Surface Deposition Process on Synthetic Macrofibers and Its Results on the Microstructure of Fiber-Reinforced Concrete.

The improvement of the mechanical properties of concrete can be achieved with the use of synthetic macrofibers. However, this fiber-matrix interaction will be sufficiently efficient for tensile efforts only when there is a binding agent that associates the characteristics of the paste with the characteristics of the surface of the reinforcing material. As already identified, in a first phase of this research using synthetic microfibers, a better fiber-matrix interaction can be achieved with the surface treatment of synthetic fibers with graphene oxide. In this way, we sought to evaluate the surface treatment with graphene oxide on two synthetic polypropylene macrofibers (macrofiber "A" and macrofiber "B") and its contribution to the concrete transition zone. The surface deposition on the macrofiber was carried out using the ultrasonication method; then, the macrofiber with the best deposition for creating reinforced concrete mixtures was identified. To evaluate the quality of GO deposition, scanning electron microscopy (SEM-FEG) and energy-dispersive spectroscopy (EDS) tests were carried out; the same technique was used to evaluate the macrofiber-matrix transition zone. The SEM-FEG images indicated that macrofiber "B" obtained greater homogeneity in surface deposition and it presented a 13% greater deposition of C in the EDS spectra. The SEM-FEG micrographs for reinforced concrete indicated a reduction in voids in the macrofiber-matrix transition zone for concretes that used macrofibers treated with GO.

A treatise on mechanical properties of natural and synthetic fibre reinforced hybrid polymer composites

Hybrid composites have proved to be a potential material attracting large scale attention for applications such as in construction, automobiles, aerospace and locomotives. In this article, a treatise on the hybrid composites types, their diversity of properties, the effect of various fibre surface treatments on mechanical properties of natural fibres and possible natural and synthetic fibre combinations for a variety of applications is presented. The mechanical characterization (tensile, flexural and impact) of different combinations of natural and synthetic fibres in thermoplastic or thermoset polymer matrices along with the critical issues is also showcased. Although the importance of hybrid composites, mechanical properties and their applications are already available in the literature, enhancing damage tolerance and impact resistance has not been duly focused by the research community.

The surface treatment of PVA fibres to enhance fibre distribution and mechanical properties of foam concrete

Fibres are often used to improve the mechanical properties of foam concrete. However, the poor dispersion of PVA fibres in foam concrete significantly restricts their reinforcement efficiency. Limited studies have been conducted on improving the distribution of PVA fibres in a cementitious matrix, particularly in relation to foam concrete. This is noteworthy because pore structure, which can be significantly influenced by the fibres and fibre treatment agents, is a critical parameter that affects the mechanical properties of foam concrete. Therefore, this study employed polar agents (non-ionic surfactants) to treat the fibre surface, aiming to enhance the distribution and reinforcement efficiency of PVA fibres in foam concrete. In view of safety and feasibility, two non-hazardous polar agents, namely PEG-PPG-PEG (designated as PA A) and Polyoxyethylene (20) cetyl ether (designated as PA B), were used to treat the PVA fibres. The impact of fibre treatments on fibre dispersion and pore structure was investigated, and the compressive strength and flexural behaviour of foam concrete were measured before and after the treatments. PA A was found to be unsuitable for fibre treatment due to its poor bonding with the fibre surface. On the other hand, PA B exhibited good bonding with PVA fibres, resulting in enhanced fibre dispersion and pore structure in the foam concrete. Compared to plain foam concrete, the fibres treated with PA B increased the compressive and flexural strength by 47.4 % and 190.3 %, respectively. Moreover, the treated fibres (by PA B) were observed to improve the 0.8 mm toughness of foam concrete by 27.2 %.

A review on natural fiber composites: Polymer matrices, fiber surface treatments, fabrication methods, properties, and applications

AbstractHigh performance and durability are essential for goods to satisfy the needs of the expanding worldwide market. Wood plastic composites (WPCs) are materials made from a combination of wood, polymers, and additives. WPCs can be extruded, injected, compressed, or thermoformed. Presently, WPCs are manufactured using sophisticated processes including as laser sintering, fused layer modeling, and additive manufacturing. Properly managing the melt temperature and pressure is crucial in the manufacturing process of WPCs to ensure effective polymer incorporation. Natural fibers have distinct benefits for polymer composites, but they also have some serious drawbacks, like lower strength properties—especially lower impact strength than synthetic fibers—poor compatibility with hydrophobic polymers, poorer dimensional stability and moisture absorption due to hydroxly groups, a maximum processing temperature that is limited, thermal degradation above 200–220°C, and lower biological durability. The modification of the surface of the fibers improves the mentioned disadvantages of the natural fibers. High‐quality WPCs require the application of chemical or physical treatment to the wood fibers. This extensive review focused on the modification techniques applied to the surface of wood, manufacturing processes, and properties and applications of WPCs.Highlights Modification methods used in surface treatment of natural fibers was explained. Properties and recent applications of wood polymer composites were given. Optimum requirements of natural fibers and polymer matrices are given. Fabrication methods of natural fiber composites are extensively given.

Plant Fiber Reinforced Polymeric Composites for Engineering Applications: A Review

Purpose: Scientists are looking for unconventional materials to achieve sustainable goals and reduce the consumption of non-renewable resources. This review focuses on polymeric composite materials with improved properties and low cost, synthesized from plant fibres and their potential fields of application. Theoretical Framework: Natural fibers, which are globally accessible, play a crucial role in improving thermal and mechanical properties when incorporated into polymers. With remarkable stiffness-density, strength and lightness, fibers stand out as promising, low-cost composite materials for applications in various areas of engineering. The plant diversity of the Amazon makes Brazil one of the largest global producers of natural fibers, providing an opportunity to develop new sustainable technologies. Method/Design/approach: Systematic literature review addressing potential applications of polymeric materials with plant fibers, fiber extraction methods, influence of fiber surface treatments and composite processing, and mechanical properties of polymeric composites with fibers. Results: Polymer composites reinforced with natural fibers are emerging as sustainable alternatives to synthetic materials, driven by their ecological nature, easy availability, low cost and biodegradability. A systematic review of the literature revealed that the mechanical properties of these composites are intrinsically linked to various factors, such as fibre orientation and length, which require careful optimization. In addition, it was observed that surface treatments, such as chemical acetylation and alkaline treatments, play a crucial role in improving the properties of plant fiber reinforced materials. These processes are responsible for removing impurities present in the cell walls of the fibers, such as lignins, waxes and hemicellulose, among others. Given Brazil's significant potential in the production of natural fibers, their application in industrial contexts is promising, offering an environmentally friendly solution for waste management. Thus, it is believed that, in the future, plant fibers will gain even more prominence, possibly effectively replacing the synthetic fibers widely used in the market. Research implications: This work contributes to the development of innovative, low-cost, sustainable materials, capable of minimizing the consumption of non-renewable resources and with potential applicability. Originality/value: The results are promising for the development of environmentally sustainable polymer composites with plant fibers, with wide applications in engineering.

Mechanical and ballistic performance of ramie fiber-reinforced polymer composites: A review

Natural fiber composites (NFCs) have seen an increased innovation and research activities due to their strength, environmental impact, and low cost. NFCs are used in aerospace, construction, leisure, packing, sport, and automotive industries. One such NFC, ramie fiber-reinforced composite has gained more importance due to its high mechanical strength, stiffness, and easy availability to all other natural fibers. In this review, an insight of the research works focusing on ramie fiber, and its reinforced polymer composite has been summarized. Factors such as fiber content, surface treatment, manufacturing techniques, and coupling agents influencing the mechanical properties (tensile, flexural, and impact) have been summarized. It is evident that the surface modification of ramie fiber through chemical treatment and the addition of coupling agents directly impact the mechanical properties of the composite. Furthermore, the usage of ramie fiber composite is still inadequate due to its poor fire and moisture-resistant properties.

Influence of fiber surface treatment on the mechanical properties of sisal fiber reinforced polylactic acid bio-composites

Influence of fiber surface treatment on the mechanical properties of sisal fiber reinforced polylactic acid bio-composites