Cellulose Micro Research Articles

Effects of cellulose micro and nanocrystals on the mechanical, thermal, morphological, and structural properties of rigid polyurethanes

Effects of adding microcrystalline cellulose (MCC) and cellulose nanocrystals (CNC) were evaluated relative to the mechanical, thermal, morphological, and structural properties of rigid polyurethanes (rPUs). The composites were prepared with the blending of polyols/isocyanates and the cellulosic fillers at 0.25%, 0.5%, and 1% loadings. Scanning electron microscopic images showed that the samples had micro-scaled porosity, with cell sizes ranging from 250 to 800 nm. The fillers improved the mechanical strengths and modulus of neat rPUs due to the presence of the nano-sized cells in rPUs matrix. The addition of both fillers generally did not provide a positive effect on the thermal properties, and the weight loss generally increased while the loading rate of the fillers was increased from 0.25% to 1%. The samples had two small crystalline peaks at 18° and 19° according to the X-ray diffraction analysis. From the results, it can be said that the presence of both fillers generally improved all properties of the neat rPUs, and the effects of CNC on the properties were higher than MCC due to both lower particle size and the higher crystallinity of CNC.

Enhanced mechanical properties of epoxy composites using cellulose micro‐ and nano‐crystals

AbstractEpoxy polymers are commonly utilized in structural applications due to their high bearing capacity and excellent chemical resistance. However, their inherent brittleness poses a significant challenge for their use in high shock and fracture strength products. To address this shortcoming, fillers can be incorporated into the polymer during preparation. In this study, we aimed to investigate the effect of incorporating cellulose‐based fillers, namely cellulose nanocrystals (CNCs) and microcrystalline cellulose (MCC), on the mechanical properties of epoxy polymer composites. The study evaluated the impact of various factors, including filler concentration, particle size, and moisture content, on the mechanical properties of the composites. The results demonstrated that the incorporation of CNC or MCC powders at concentrations below 5% could enhance the mechanical properties of the resulting epoxy composites without adversely affecting their surface and thermal properties. The maximum tensile strength and fracture toughness of the filler‐based epoxy composites were achieved at 2 and 4 wt% for CNCs and MCC, respectively. CNCs with a smaller particle size distribution were found to be much more effective than MCC in improving the mechanical properties of the epoxy composites. Furthermore, utilizing dried fillers resulted in a higher improvement in tensile strength, which was achieved at lower filler concentrations.

PROCESSING AND CHARACTERIZATION OF MICRO AND NANOCELLULOSE FIBRES PRODUCED BY A LAB VALLEY BEATER (LVB) AND A SUPER MASSCOLLOIDER (SMC)

Cellulose nanofibers, known for their high aspect ratio (>150), are difficult to process and characterize due to a variety of reasons, including lower diameters. In this work, cellulose micro and nanofibers produced by a Lab Valley Beater (LVB) and a Super Masscolloider (SMC) were characterized using optical microscopy and SEM. The thermal degradation behavior was analyzed using thermogravimetric analysis and solar radiation tests. With decreasing clearance between two grinders, SMC refining resulted in fibres with smaller diameter (400 nm to 8 μm) and a marginal increase in the number of fines was noted. LVB refining resulted in fibres with shorter length (500 μm), but a significant increase in the number of fines, contributing to higher tensile strength. The tensile strength of SMC sheets was 10-fold lower and severe ductile fracture was observed when compared to LVB refining. However, a 30 °C increase in thermal stability was found for fibres produced by SMC compared to LVB refining. This could be due to lesser heterogeneity in fibre morphology (reduced packing density), lack of surface fibrillation (reduced mechanical interlocking) and altered cellulose-lignin interaction for SMC refined fibres. Hence, it can be recommended to use blends of LVB and SMC refined fibres to make sheets for applications involving higher temperatures (250 °C) and higher tensile strengths (25 MPa), but the sheets need to be fabricated using the cast evaporation technique by maintaining the water bath temperature at 95-98 °C. The dust capturing ability of SMC sheets was tested using a dust sampler and it was found that sheet SMC_0.01 can capture PM2.5 dust particles, i.e. a weight increase of 7% was noticed in 6 h.

Flexoelectric and piezoelectric effects in micro- and nanocellulose films

In this work, we evaluated the flexoelectric and piezoelectric contributions to the overall macroscopic polarization in cellulose films. To this end, the flexoelectric μ31 and transverse effective piezoelectric e31,f coefficients of cellulose films were determined using cantilever beam bending. The experiments were based on theoretical developments allowing to separate the flexoelectric from the piezoelectric contribution, represented by an effective flexoelectric coefficient, μeff, depending on both e31,f and μ31. Five free-standing and stainless steel/cellulose bilayer films were prepared from cellulose showing different morphologies and surface charge degrees: two almost neutral cellulose microfibers (CMF) and three (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized cellulose micro- (TCMF) and nanofibers (TCNF) bearing negative charged groups on the surface.The dielectric properties of the films indicated a low dielectric constant for unmodified CMF, and a huge increase for TEMPO-oxidized samples, which were up to 9 times higher than poly(vinylidene fluoride)-based polymers. TEMPO-oxidized cellulose films exhibited the largest flexoelectric coefficients (almost 7 times higher than those of synthetic polymer dielectrics), which evidenced that the presence of polar groups and surface charge boosted both flexoelectricity and piezoelectricity in unpoled cellulose films. These findings pave the way towards sustainable cellulose-based curvature sensors with large effective flexoelectric coefficients, without the need of preliminary energy consuming poling step.

Biodegradable Polyethylene-Based Composites Filled with Cellulose Micro- and Nanoparticles

Composite materials filled with cellulose particles (microcrystalline cellulose and nanocellulose) have good prospects for use in various fields. Microcrystalline cellulose (MCC) and nanocellulose (NC) were isolated by chemical and physical methods and investigated. Composite materials based on polyethylene (PE) were obtained using MCC and NC as fillers (5–20 wt.%) and maleic anhydride grafted low molecular weight polyethylene (MA-g-LMPE) as a compatibilizer. The structure and morphology of the composites and fillers were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, thermal analysis (TA), transmission electron microscopy (TEM), atomic force microscopy (AFM), and the strength properties were determined by tensile testing. An increase in the crystallinity index and mechanical strength of composites at low filler contents (up to 5 wt.%) was revealed. The size of the cellulose particles significantly affects the structure and properties of composites. Although the general picture of the effect of fillers on the crystalline structure and mechanical properties is similar, the addition of NC had a greater effect than МСС. The results of this study showed the possibility of using MCC and NC as reinforcement materials in composites, and they have biodegradable properties.

Isolation of cellulose microfibers and nanofibers by mechanical fibrillation in a water-free solvent

Cellulose from vegetable sources is the most abundant biopolymer on earth. In plants, cellulose is a reinforcement element that conforms to a hierarchical structure. Cellulose micro-/nanofibers can be isolated from the cell wall by top-down strategies involving mechanical processes to be used in applications as a reinforcing material. Nonetheless, its use has been limited as its extraction in an aqueous medium is unfavorable when employed in low-hydrophilic matrices. Therefore, this work proposes a novel homogenization route in which cellulose micro-/nanofibers are directly obtained and dispersed in propylene glycol (PG), which generates more possibilities for these (nano) structures in applications that require water-free environments. Moreover, the influence on the cycle numbers in the morphological, chemical, thermal, and rheological properties was researched. Thus, the obtained micro-/nanofibers presented TEM diameters even below 20 nm. XRD analysis evidenced crystalline planes located at 1overline{1 }0, 110, and 200, and crystallinity degree values up to 80%. Also, FTIR spectra bands in 3340 cm−1, 2890 cm−1, 1314 cm−1, and in the fingerprint region corresponded to native cellulose Iβ. FTIR and TGA confirmed no influence of mechanical cycles on cellulose fibers’ chemical and thermal properties. Furthermore, the increase in the cycle number evidenced a shear-thinning rheological behavior of the suspensions. Considering the above results, it was concluded that the proposed high-pressure homogenization within PG is an approach for vegetable nanocellulose homogenization while maintaining high crystallinity, thermal, and chemical features with huge importance for subsequent processes in the development of nanocomposites with hydrophilic matrices for industrial applications.Graphical abstract

Effect of ultrafine grinding and ultrasonication duration on the performance of polyvinyl alcohol (PVA) agave gigantea cellulose micro fiber (CMF) bio-composite film

ABSTRACT This paper aims to assess the effect of ultrafine grinding and ultrasonication treatment on the bio-composite characteristics of polyvinyl alcohol (PVA) Agave gigantea (AG) Cellulose Micro Fiber (CMF) bio-composite film performance. This study included five different types of samples. FESEM investigation of PVA/CMF revealed a fiber diameter of 10–15 μm. According to X-ray diffraction, the CMF bio-composite has the highest crystallinity index (87%). The bio-composite film was as transparent as the pure PVA film, demonstrating that the CMF was uniformly dispersed throughout the film. Tensile testing revealed that the ultrafine grinding and ultrasonication treatment for 2 h (PVA/U2) increased tensile strength by 43% compared to the untreated PVA/CMF sample. This finding is confirmed by thermogravimetry analysis (TGA) and derivative (DTG) analyses, which show that the PVA/U2 sample has the most significant degree of thermal stability when compared to other samples. An ANOVA output supports the results of this experiment with an R2 value of 0.94600232 at a 95% confidence level. The p-value of 0.000079 and F-value of 10.80004 for ultrafine grinding and ultrasonication duration on AG leaf-based PVA bio-composite revealed a statistically significant influence on the studied parameters.

Mechanically strong nanopapers based on lignin containing cellulose micro- and nano-hybrid fibrils: Lignin content-fibrils morphology-strengthening mechanism

Lignin-containing cellulose nanopapers are emerging multifunctional materials in the fields of coatings, films, and packaging. However, the forming mechanism and properties of nanopapers with various lignin content have not been thoroughly studied. In this work, a mechanically strong nanopaper was fabricated based on lignin-containing cellulose micro- and nano-hybrid fibrils (LCNFs). The influence of lignin content and fibrils morphology on the formation process of nanopapers was investigated to understand the strengthening mechanism of nanopapers. LCNFs with high lignin content provided nanopapers with intertwined micro- and nano-hybrid fibrils layers with small layer spacing, while LCNFs with low lignin content offered nanopapers interlaced nanofibrils layers with large layer spacing. Although lignin was expected to interfere with hydrogen bonds between fibrils, the uniformly distributed lignin contributed to the stress transfer between fibrils. Due to the good coordination between microfibrils, nanofibrils and lignin (as network skeleton, filler and natural binder, respectively), the well-designed LCNFs nanopapers with lignin content of 14.5 % showed excellent mechanical properties, including tensile strength (183.8 MPa), Young's modulus (5.6 GPa) and elongation (9.2 %). This work deeply reveals the relationship between lignin content, morphology and strengthening mechanism of nanopapers, and providing theoretical guidance for employing LCNFs as structural and reinforcing materials to design robust composites.

Sustainability of cellulose micro-/nanofibers: A comparative life cycle assessment of pathway technologies

Cellulose micro- and nanofibers (CNFs) are commonly regarded as “greener” than petro-based materials. The high energy input that their production still demands, along with the use of chemicals or heat in some pretreatments, asks for a critical view. This paper attempts a life cycle assessment of CNFs produced from bleached hardwood kraft pulp via three different pre-treatments before mechanical homogenization. First, a fully mechanical route, based on a Valley beating pre-treatment. Second, an enzymatic route, based on endoglucanases and requiring certain temperature (~50 °C). Third, a TEMPO-mediated oxidation route, considering not only the impact of the chemical treatment itself but also the production of TEMPO from ammonia and acetone. The main output of the study is that both, mechanical and TEMPO-mediated oxidation routes, present lower impacts than the enzymatic pre-treatment. Although the mechanical route presents slightly milder contributions to climate change, acidification, eutrophication, and other indicators, saying that TEMPO-mediated oxidation is environmentally unfeasible should be put under question. After all, and despite being disregarded in most assessment publications up to date, it is the only well-known way to selectively oxidize primary hydroxyl groups and thus producing kinds of CNFs that are unthinkable by other ways.

An investigation on Moringa oleifera fruit (drumstick)‐derived cellulose micro and nanofiber reinforced styrene butadiene rubber composites

AbstractThe current focus in the elastomer industry is to look for biobased or natural filler for various compounds. The reinforcing effect of waste drumstick‐derived cellulose micro and nanofiber in styrene butadiene rubber (SBR) was investigated for the very first time. Cellulose microfibers and nanofibers were isolated from the drumstick fruit peel and characterized using different techniques such as x‐ray diffraction, scanning and transmission electron microscopy, and x‐ray photoelectron spectroscopy. The filler‐polymer interaction in the composites was studied using the bound rubber measurements, which showed that the bound rubber content of the composite increased from 0.5% to 8.1% at 5 phr cellulose nanofiber loading. The tensile strength and modulus of the modified cellulose microfiber‐containing composite were higher than both the unfilled SBR and the raw fiber‐SBR composites. The addition of 5 phr nanofiber to SBR showed a 46% increment of the tensile strength than the control compound. The die swell index of the cellulose fiber reinforced composites came down attesting the better processability of the extrudates. The addition of cellulose fiber also improved the wet skid resistance of the composites as seen from dynamic mechanical thermal analysis. Hence, this work confirms the application of modified drumstick microfibers and nanofibers as sustainable fillers for high‐performance elastomers composites.

Disk-shaped cellulose fibers from red algae, Eucheuma cottonii and its use for high oxygen barrier

We could prepare disk-shaped fibers without particular mechanical treatments from Eucheuma cottonii, the commonly used red algae for obtaining carrageenan. After carrageenan extraction from cottonii, the residues were bleached using chlorine dioxide and hydrogen peroxide. The morphology of the bleached fiber was disk-shaped one with a very thin fiber wall thickness of less than 100 nm and a diameter of approximately 100 μm. The sugar analysis and X-ray diffraction of the bleached fibers showed that they consisted of mostly glucose and had the same pattern as cellulose I with more than 50% crystalline structure, respectively. Compared to one-dimensional cellulose micro- or nanofibrils, which exhibits slow drainage and possess intolerably high drying energy, these two-dimensional disk-shaped fibers, when formed a layer in water medium, exhibit fast drainage and low drying energy. The formed sheet resulted in excellent transparency and high oxygen barrier property. Therefore, by using these disk-shaped, thin fibers from cottonii, we expect that the biodegradable and transparent oxygen barrier layer can be produced at a paper machine, which is, if possible, extremely difficult in the case of cellulose micro- or nanofibrils due to their slow drainage and high drying energy.

Cellulosic Microfiber Extraction from Ecofriendly Bahunia Racemosa and Its Characterization

ABSTRACT Recent demand of eco-friendly advanced materials for automotive components motivated to develop natural fiber-reinforced composites due to their extraordinary properties with minimum weight at low cost. The reinforcement of microcellulosic extracted from lignocellulosic materials can enhance the mechanical properties with astonishing the biodegradability quality in the polymer-based composites. Bahunia racemosa (BR) fibers were chosen to extract cellulose microfibers through chemo-mechanical method and the chemical compositions at different stages are determined by using ASTM standards. The average diameter of the extracted cellulose micro Bahunia racemosa fibers (CMBRF) found as 10 μm. The microfiber composites are fabricated at different weight fractions such as 20, 30, 40 and 50 by compression molding method. Surface properties of the produced fibers and fabricated composite structures are analyzed through microscopic techniques. The influence of reinforcement effect on the mechanical properties of fabricated composite structures is analyzed through standard testing methods. The composites reinforced with 40 wt% of cellulose microfibers exhibited highest enhancement about the tensile strength and young modulus of 80.25 and 40%, respectively. The proposed composites can be used to make various low cost, light weight composite materials for industrial and construction industries.

Structure and Properties of Cellulose/Mycelium Biocomposites.

The current environmental problems require the use of low-energy, environmentally friendly methods and nature-like technologies for the creation of materials. In this work, we aim to study the possibility of the direct biotransformation of fibrillar cellulose by fungi through obtaining a cellulose/mycelium-based biocomposite. The cellulose micro- and nanofibrils were used as the main carbon sources in the solid-phase cultivation of basidiomycete Trametes hirsuta. The cellulose fibrils in this process act as a template for growing mycelium with the formation of well-developed net structure. The biotransformation dynamics of cellulose fibrils were studied with the help of scanning electron microscopy. The appearance of nitrogen in the structure of formed fibers was revealed by elemental analysis and FTIR-spectroscopy. The fibers diameters were estimated based on micrograph analysis and the laser diffraction method. It was shown that the diameter of cellulose fibrils can be tuned by fungi through obtaining cellulose-based mycelium fibers with a narrower diameter-size distribution as compared to the pristine cellulose fibrils. The morphology of the resulting mycelium differed when the micro or nanofibrils were used as a substrate.

Modification of Cellulose Micro- and Nanomaterials to Improve Properties of Aliphatic Polyesters/Cellulose Composites: A Review.

Aliphatic polyesters/cellulose composites have attracted a lot attention due to the perspectives of their application in biomedicine and the production of disposable materials, food packaging, etc. Both aliphatic polyesters and cellulose are biocompatible and biodegradable polymers, which makes them highly promising for the production of “green” composite materials. However, the main challenge in obtaining composites with favorable properties is the poor compatibility of these polymers. Unlike cellulose, which is very hydrophilic, aliphatic polyesters exhibit strong hydrophobic properties. In recent times, the modification of cellulose micro- and nanomaterials is widely considered as a tool to enhance interfacial biocompatibility with aliphatic polyesters and, consequently, improve the properties of composites. This review summarizes the main types and properties of cellulose micro- and nanomaterials as well as aliphatic polyesters used to produce composites with cellulose. In addition, the methods for noncovalent and covalent modification of cellulose materials with small molecules, polymers and nanoparticles have been comprehensively overviewed and discussed. Composite fabrication techniques, as well as the effect of cellulose modification on the mechanical and thermal properties, rate of degradation, and biological compatibility have been also analyzed.

Gel Point as Measurement of Dispersion Degree of Nano-Cellulose Suspensions and Its Application in Papermaking.

The dispersion degree of cellulose micro and nanofibrils (CMFs/CNFs) in water suspensions is key to understand and optimize their effectiveness in several applications. In this study, we proposed a method, based on gel point (Øg), to calculate both aspect ratio and dispersion degree. This methodology was validated through the morphological characterization of CMFs/CNFs by Transmission Electronic Microscopy. The influence of dispersion degree on the reinforcement of recycled cardboard has also been evaluated by stirring CMF/CNF suspensions at different speeds. Results show that as stirring speed increases, Øg decreased to a minimum value, in which the aspect ratio is maximum. Then, Øg increased again. Suspensions with lower Øg, in the intermediate region of agitation present very good dispersion behavior with an open and spongy network structure, in which nanofibril clusters are totally dispersed. Higher stirring speeds shorten the nanofibrils and the networks collapse. Results show that the dispersion of the nanocellulose at the minimum Øg before their addition to the pulp, produces higher mechanical properties, even higher than when CNFs and pulp are agitated together. This method allows for the determination of the CMF/CNF dispersion, to maximize their behavior as strength agents. This knowledge would be crucial to understand why some industrial trials did not give satisfactory results.

Thermo-Reversible Cellulose Micro Phase-Separation in Mixtures of Methyltributylphosphonium Acetate and γ-Valerolactone or DMSO.

We have identified cellulose solvents, comprised of binary mixtures of molecular solvents and ionic liquids that rapidly dissolve cellulose to high concentration and show upper‐critical solution temperature (UCST)‐like thermodynamic behaviour ‐ upon cooling and micro phase‐separation to roughly spherical microparticle particle‐gel mixtures. This is a result of an entropy‐dominant process, controllable by changing temperature, with an overall exothermic regeneration step. However, the initial dissolution of cellulose in this system, from the majority cellulose I allomorph upon increasing temperature, is also exothermic. The mixtures essentially act as ‘thermo‐switchable’ gels. Upon initial dissolution and cooling, micro‐scaled spherical particles are formed, the formation onset and size of which are dependent on the presence of traces of water. Wide‐angle X‐ray scattering (WAXS) and 13C cross‐polarisation magic‐angle spinning (CP‐MAS) NMR spectroscopy have identified that the cellulose micro phase‐separates with no remaining cellulose I allomorph and eventually forms a proportion of the cellulose II allomorph after water washing and drying. The rheological properties of these solutions demonstrate the possibility of a new type of cellulose processing, whereby morphology can be influenced by changing temperature.

Spherical Cellulose Micro and Nanoparticles: A Review of Recent Developments and Applications.

Cellulose, the most abundant natural polymer, is a versatile polysaccharide that is being exploited to manufacture innovative blends, composites, and hybrid materials in the form of membranes, films, coatings, hydrogels, and foams, as well as particles at the micro and nano scales. The application fields of cellulose micro and nanoparticles run the gamut from medicine, biology, and environment to electronics and energy. In fact, the number of studies dealing with sphere-shaped micro and nanoparticles based exclusively on cellulose (or its derivatives) or cellulose in combination with other molecules and macromolecules has been steadily increasing in the last five years. Hence, there is a clear need for an up-to-date narrative that gathers the latest advances on this research topic. So, the aim of this review is to portray some of the most recent and relevant developments on the use of cellulose to produce spherical micro- and nano-sized particles. An attempt was made to illustrate the present state of affairs in terms of the go-to strategies (e.g., emulsification processes, nanoprecipitation, microfluidics, and other assembly approaches) for the generation of sphere-shaped particles of cellulose and derivatives thereof. A concise description of the application fields of these cellulose-based spherical micro and nanoparticles is also presented.

Novel bionanocomposite of polycaprolactone reinforced with steam-exploded microfibrillated cellulose modified with ZnO

Polycaprolactone (PCL) bionanocomposites reinforced with microfibrillated cellulose (MFC), either plain or modified with 2 wt% of zinc oxide (ZnO) nanoparticles, were first time developed for possible application as multifunctional packing. The MFC was obtained by an alkali treatment, a steam explosion process, and ZnO modification applied to parchment (PAR), a husk waste from the coffee industry. X-ray diffraction (XDR), thermogravimetric analysis (TGA/DTG), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), tensile tests, and CO2 permeability characterized the MFCs and the bionanocomposites. As for the MCFs, the crystallinity index of 50.6% measured by XRD for the plain PAR fiber increases with the combined alkaline treatment and steam explosion (CFA/EXP) to 68.2%, and further with ZnO modification (ZnO-CFA/EXP) to 80.1%. TGA/DTG displays a rising onset of thermal degradation from 214 to 306 °C, as well as maximum degradation rate from 330 to 350 °C, for PAR and ZnO-CFA/EXP, respectively. Regarding the nanocomposites, the addition of 3 wt% of alkali/steam explosion and ZnO-modified CFA/EXP contributes to enhancing thermal stability. Tensile tests disclosed improved mechanical properties of the novel nanocomposites as compared to the PCL matrix. In particular, Young's modulus rose from 88.5 to 169.5 MPa for the plain PCL and PCL reinforced with 3(ZnO-CFA/EXP), respectively. SEM images evidenced the participation of cellulose micro and nanofibrils in the PCL matrix. Approximately 20% reduction in the CO2 permeability coefficient of both PCL and its 3CFA/EXP nanocomposite compared with 3(ZnO-CFA/EXP) proved that the ZnO nanoparticles provide a gas barrier to the nanocomposite, a convenient property for food packing.

A Review on Micro- to Nanocellulose Biopolymer Scaffold Forming for Tissue Engineering Applications.

Biopolymers have been used as a replacement material for synthetic polymers in scaffold forming due to its biocompatibility and nontoxic properties. Production of scaffold for tissue repair is a major part of tissue engineering. Tissue engineering techniques for scaffold forming with cellulose-based material is at the forefront of present-day research. Micro- and nanocellulose-based materials are at the forefront of scientific development in the areas of biomedical engineering. Cellulose in scaffold forming has attracted a lot of attention because of its availability and toxicity properties. The discovery of nanocellulose has further improved the usability of cellulose as a reinforcement in biopolymers intended for scaffold fabrication. Its unique physical, chemical, mechanical, and biological properties offer some important advantages over synthetic polymer materials. This review presents a critical overview of micro- and nanoscale cellulose-based materials used for scaffold preparation. It also analyses the relationship between the method of fabrication and properties of the fabricated scaffold. The review concludes with future potential research on cellulose micro- and nano-based scaffolds. The review provides an up-to-date summary of the status and future prospective applications of micro- and nanocellulose-based scaffolds for tissue engineering.

Micro Cellulose Grewia Optiva Fiber-reinforced Polymer Composites: Relationship between Structural and Mechanical Properties

ABSTRACT Bio-based composites are getting popular due to its major contribution to the green materials industry application. Green techniques reduce the toxic gas emission, waste generation and improve environmental protection. The extraction of cellulose microfibers from natural fibers using the steam explosion technique is a cost-effective and traditional method. In this study, cellulose microfiber was extracted from raw Grewia optiva (GO) fiber by a chemo-mechanical method. Chemical treatments like alkaline treatment, steam explosion, bleaching, and acid treatment are used. Also, mechanical defibrillation of fiber was carried out by stirring and homogenization. The chemical compositions of various stages were determined by using ASTM standards. The microscopic, XRD, FTIR and TGA techniques were used to analyze structural and morphological properties of fibers. The extracted cellulose micro Grewia optiva fibers (CMGOF) had an average diameter of 10 μm. TGA results indicated that the thermal properties of isolated cellulose microfibers are improved after chemical treatment. The cellulose micro Grewia optiva fibers reinforced epoxy composites were fabricated adopting the compression molding method by varying the fiber ratio. Also, the mechanical properties of composites with various fiber ratios were investigated. The experimental results revealed that composite having 40 wt% of fiber has shown higher tensile, impact strength and hardness properties.