Sisal Cellulose Fibers Research Articles

Synthesis and evaluation of the incorporation of sisal fiber cellulose in the polymeric matrix of starch from jackfruit seed (Artocarpus heterophyllus Lam.) using thermogravimetry

Synthesis and evaluation of the incorporation of sisal fiber cellulose in the polymeric matrix of starch from jackfruit seed (Artocarpus heterophyllus Lam.) using thermogravimetry

Natural Cellulose Fibers for Surgical Suture Applications.

Suture biomaterials are critical in wound repair by providing support to the healing of different tissues including vascular surgery, hemostasis, and plastic surgery. Important properties of a suture material include physical properties, handling characteristics, and biological response for successful performance. However, bacteria can bind to sutures and become a source of infection. For this reason, there is a need for new biomaterials for suture with antifouling properties. Here we report two types of cellulose fibers from coconut (Cocos nucifera) and sisal (Agave sisalana), which were purified with a chemical method, characterized, and tested in vitro and in vivo. According to SEM images, the cellulose fiber from coconut has a porous surface, and sisal has a uniform structure without internal spaces. It was found that the cellulose fiber from sisal has mechanical properties closer to silk fiber biomaterial using Ultimate Tensile Strength. When evaluating the cellulose fibers biodegradability, the cellulose from coconut showed a rapid weight loss compared to sisal. The antifouling test was negative, which demonstrated that neither possesses intrinsic microbicidal activity. Yet, a weak biofilm was formed on sisal cellulose fibers suggesting it possesses antifouling properties compared to cellulose from coconut. In vivo experiments using healthy mice demonstrated that the scarring and mechanical connection was like silk for both cellulose fibers. Overall, our results showed the potential use of cellulose fibers from vegetal for surgical sutures due to excellent mechanical properties, rapid degradation, and no bacterial adhesion.

Hyperbranched Liquid Crystals Modified with Sisal Cellulose Fibers for Reinforcement of Epoxy Composites.

Well-defined functionalized sisal cellulose fibers (SCFs) grafted on hyperbranched liquid crystals (HLP) were synthesized to improve the compatibility between SCFs and epoxy resin (EP). The influence of SCFs-HLP on the mechanical and thermal properties of SCFs-HLP/EP composites was studied. The results show that the mechanical properties of SCFs-HLP/EP composites were enhanced distinctly. Particularly, compared with EP, impact strength, tensile strength, and flexural strength of composites with 4.0 wt % SCFs-HLP were 38.3 KJ·m−2, 86.2 MPa, and 150.7 MPa, increasing by 118.7%, 55.6%, and 89.6%, respectively. As well, the glass transition temperature of the composite material increased by 25 °C. It is hope that this work will inform ongoing efforts to exploit more efficient methods to overcome the poor natural fiber/polymer adhesion in the interface region.

Fabrication of functional biomass carbon aerogels derived from sisal fibers for application in selenium extraction

Selenium (Se) is a rare element, usually in ionic form in aqueous media. The separation of selenium from aqueous solution has received considerable attention due to the large-batch application of selenide. In this work, the Mg–Al layered double hydroxides (LDHs)-functionalized biomass carbon aerogels (CAs) were fabricated by combining freeze-drying, carbonization with in-situ growth method. And the process for extracting selenium based on adsorption of CAs and “memory effect” of LDHs nanosheets has been developed. Firstly, CAs was prepared by alkalization, bleaching, freeze-drying and carbonization using the sisal fiber as precursor. Then, Mg–Al LDHs-functionalized CAs were fabricated by in situ growth of LDHs platelets on the CAs surfaces. The physical and chemical properties of the LDHs-functionalized CAs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET). The SEM results showed that sisal cellulose fibers used in this paper have a smooth surface with a diameter about 8μm and a length of several millimeters. Furthermore, the flowerlike nanosheets are uniform in both size and shape, with each LDHs nanoplatelet grafted to the CAs. The nitrogen sorption analysis confirmed that LDHs-functionalized CAs is mesoporous structure with the mesopores centered at about 3.5–5nm and BET surface area of 165.26m2/g. It is indicated that the maximum adsorption capacity of selenium on LDHs-functionalized CAs reached 73.6mg[Se]/g. The adsorption time profile of selenium onto LDHs-functionalized CAs ndicates that the adsorption equilibrium was achieved within 4h. After recycling 9 times, the regenerated LDHs-functionalized CAs still displayed high selenium absorption properties. Therefore, the high absorption capacity and excellent recycling capabilities of LDHs-functionalized CAs composites give the material an ideal choice for the selenium recovery in practical applications.

Improvement of shape stability and thermal properties of PCM using polyethylene glycol (PEG)/sisal fiber cellulose (SFC)/graphene oxide (GO)

This study prepared a polyethylene glycol (PEG)/sisal fiber cellulose (SFC)/graphene oxide (GO) composite using a novel dynamic impregnating method to obtain a high-performance shape-stabilized phase change materials (PCMs). In this material, the ternary system PEG served as the latent heat storage material and SFC and GO served as the supporting materials. The structure, morphology, thermal conductivity, phase change temperature, and latent heat of the composite PCMs were characterized by fourier transform infrared spectroscopy, wide-angle X-ray diffraction, polarizing microscope, digital camera, scanning electron microscopy, differential scanning calorimetry, and thermal conductivity analysis. Results show that the composite PCMs exhibit a fine impregnation morphology and excellent shape-stabilized feature during the phase change process, the shape of the PEG/SFC/GO composite PCMs are unchanged even after being placed on a 85 °C hot plate. Thermal behavior tests indicate that the composite PCM (PEG weight percentage of 80 wt.%) shows a high latent heat storage capacity of approximate 140 J/g after more than 100 thermal cycling, and exhibits good heat-conducting performance.

Mechanical properties of phenol/formaldehyde resin composites reinforced by cellulose microcrystal with different aspect ratio extracted from sisal fiber

Sisal cellulose fiber (SCF) and sisal fiber cellulose microcrystal (SFCM), produced with sulfate pulping method and ball‐milling approach separately, were in‐situ polymerized and dispersed into phenol/formaldehyde (PF) resin, to manufacture SCF/PF and SFCM/PF composites via rolling and molding method and investigate the effect of SCF and SFCM on the impact, flexural, and dynamic mechanical properties of the SCF/PF and SFCM/PF composites. As a result, under the condition of same content, SFCM could preferably enhance these properties maybe resulting from the better dispersion in resin matrix than SCF. In particular, when SFCM content was 7%, the impact strength and equilibrium relaxation modulus of the SFCM/PF composite were increased by 26.5% and 37.7%, while the creep deformation was decreased by 26.5%. In addition, when SFCM content was 5%, the flexural strength, initial storage modulus and glass transition temperature of SFCM/PF composite were increased by 8.5%, 22.6%, and 13°C. Copyright © 2016 John Wiley & Sons, Ltd.

Enhanced thermal and mechanical properties of epoxy composites by addition of hyperbranched polyglycerol grown on cellulose fibers

We reported a novel approach for epoxy composites by incorporation of hyperbranched polyglycerol (HPG) grafted sisal cellulose fibers (SCF). In this work, we have synthesized SCF wrapped HPG shell (SCF-g-HPG) by a “grafting from” strategy for the strong interfacial interaction between fillers and matrix. It was found that the thermal and mechanical properties of epoxy composites were greatly improved by incorporating SCF-g-HPG. For example, the impact strength, flexural strength, tensile strength, Young’s modulus and toughness of the composites with 3.0 wt% SCF-g-HPG loading were 38.35 KJ/m2, 123.40 MPa, 86.62 MPa, 151.7 MPa, and 417.84 MJ/m3, significantly increased by 119.1 %, 55.2 %, 45.6 %, 43.1 %, and 166.1 % respectively, as compared with neat epoxy. In addition, thermal stability of SCF-g-HPG/epoxy composites also showed an obvious enhancement compared with neat epoxy.

Dynamic mechanical properties of sisal fiber cellulose microcrystalline/unsaturated polyesterin‐situcomposites

Sisal is a natural material and a potential additive to reinforce composites. In this paper, sisal fiber cellulose microcrystalline (SFCM) was obtained from sisal fiber, and SFCM/unsaturated polyester (SFCM/UPR)in‐situresins were prepared viain‐situpolymerization. Moreover, SFCM/UPR composites were produced with methods of rolling and molding. Effect of SFCM on dynamic mechanical properties of composites was studied. It is demonstrated that SFCM could significantly improve the dynamic mechanical properties of composites; the effect is closely related with the amount of SFCM, its dispersion in UPR matrix, and interfacial interaction. When the content of SFCM was 3 wt%, at 50°C, the storage modulus of SFCM/UPR composite was 33.22% higher than that of pure UPR. In addition, the glass transition temperature (Tg) was shifted to a higher temperature by 7.5°C, and loss modulus was decreased by 16.24%. The equilibrium value of relaxation modulus at 120 min was 30.52% higher than that of pure UPR composite. Besides, the equilibrium value of creep strain at 120 min was decreased by 41.61% compared with pure UPR composite. Copyright © 2015 John Wiley & Sons, Ltd.

Effects of preparation methods on mechanical and tribological properties of SFCM/UP composites

In this paper, the effects of preparation methods on mechanical and tribological properties of sisal fiber cellulose microcrystalline (SFCM)/unsaturated polyester (UP) composites were studied. Compared with the pure UP composites, the SFCM/UP composites prepared by in‐situ polymerization had greatly improved the mechanical and tribological properties. The impact strength, flexural strength, and flexural modulus of SFCM/UP composites with 2 wt% SFCM were 6.8 KJ/M2, 105.53 MPa, and 14.29 GPa, increased by 74.81%, 33.38%, and 7.36% in comparison with pure UP composites, respectively. Meanwhile, the volume wear rate of SFCM/UP composites at 100, 150, and 200°C decreased 50.40%, 52.39%, and 50.06%, respectively. These results suggested that the properties of SFCM/UP composites prepared by in‐situ polymerization were significantly improved, which may be attributed to the strong interface interactions between SFCM and UP matrix. Copyright © 2015 John Wiley & Sons, Ltd.

Impact of Layer-by-Layer Self-Assembly Clay-Based Nanocoating on Flame Retardant Properties of Sisal Fiber Cellulose Microcrystals

The renewable cationic polyelectrolyte chitosan (CH) and anionic nanomontmorillonite (MMT) layers were alternately deposited on the surface of sisal fiber cellulose microcrystals (SFCM) via layer-by-layer (LBL) self-assembly method. The structure and properties of the composites were characterized by zeta potential, thermal gravimetric analysis (TGA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectrometer (FTIR), microcalorimeter (MCC), and so forth. The zeta potential results show that the cellulose microcrystalline surface charge reversed due to the adsorption of CH and MMT nanoplatelets during multilayer deposition. MMT characteristic diffraction peaks appear in XRD patterns of SFCM(CH/MMT)5and SFCM(CH/MMT)10composites. Additionally, FESEM reveals that the SFCM(CH/MMT)10surface is covered with a layer of material containing Si, which has been verified by elemental analysis. TGA results show that the initial decomposition (weight loss of 5%) temperature of SFCM(CH/MMT)5is increased by 4°C compared to that of pure SFCM. On the other hand, carbon residue percentage of SFCM(CH/MMT)10is 25.1%, higher than that of pure SFCM (5.4%) by 19.7%. Eventually, it is testified by MCC measurement that CH/MMT coating can significantly reinforce the flame retardant performance of SFCM.

Mechanical and Wear Properties of Sisal Fiber Cellulose Microcrystal Reinforced Unsaturated Polyester Composites

ABSTRACTIn this paper, sisal fiber cellulose microcrystal (SFCM) was prepared by the sulfate pulping method, and sisal fiber cellulose microcrystal/unsaturated polyester (SFCM/UP) in situ resin was polymerized. Furthermore, the SFCM/UP composite was prepared by rolling and molding techniques. Effects of SFCM content on mechanical and wear properties of the UP composites were studied. Structure and properties of the in situ SFCM/UP resin and its composites were characterized by using Fourier transform infrared, polarized optical microscopy, thermogravimetric analysis, scanning electron microscopy, and other methods. The results showed that the addition of SFCM by in situ polymerization significantly improves the thermal stability of UP: The decomposition temperature (Td5) of SFCM/UP in situ resin, at thermal weight loss of 5%, is increased by 16°C compared to that of the pure UP resin. On a condition that the SFCM content was 2%, the impact strength, flexural strength, and flexural modulus of SFCM/UP composites are higher than those of UP composites by 41.08%, 52.52%, and 32.31%, respectively. Moreover, the addition of SFCM significantly enhances the wear properties of unsaturated polyester composite at 200°C; the volume wear rate of SFCM/UP composite is lower than that of UP composites by 64%, indicating SFCM could significantly strengthen and toughen UP composites.

Surface Modification of Sisal Fiber Cellulose Microcrystallites by a Renewable Flame-Retardant CH/PA Coating

Sisal fiber cellulose microcrystallines(SFCM) was coated with a fully renewable flame-retardant coatings consisted of cationic chitosan(CH) and anionic phytic acid(PA) via layer-by-layer(LbL) assembly. The structure and properties of the formed microcrystallite composite were characterized by Zeta potential, TGA, FESEM, VFT, and MCC methods. Zeta potential and FESEM results show that the surface charge of the coated cellulose microcrystallites reversed due to the adsorption of polyelectrolyte during multilayer deposition process. TG analysis show that the initial decomposition temperature of the composites decreased from 299℃ to 257℃ and the residues increased from 5.41% up to 37.34% with the increase of CH/PA film layers. Examination of SFCM(CH/PA) 5 residues by FESEM revealed that the distinct fiber structure have been preserved and insignificant fiber shrinkage was observed.Vertical combustion testing(VFT)results show that for SFCM(CH/PA)5, in comparison with the plain SFCM, the afterflame time is drops from 150 s down to 39 s; the pkHRR and total heat release(HR)exhibit great reduction of 70.6% and 79.2% respectively. These results demonstrate that the CH/PA coating has obviously improved the flame retardant performance of SFCM.

Comparative Study of the Effects Induced by Different Laccase-Based Systems on Sisal Cellulose Fibers

This paper reports a comparative study of the effects induced on sisal pulp fibers by three different laccase-based systems, namely, laccase–sinapyl aldehyde, laccase–ferulic acid, and laccase–TEMPO systems, applied to perform biobleaching, biografting, and cellulose oxidation, respectively. (The abbreviations SLD, FRC, and TEMPO are used to represent sinapyl aldehyde, ferulic acid, and the 2,2,6,6-tetramethylpiperidine-1-oxyl free radical.) A novel aspect of this study was the use of thermogravimetric analysis (TGA) to monitor surface changes in cellulosic microfibrils during the enzyme treatments and gain a greater understanding of the mechanisms of action of the laccase-based systems. The different modes of action of the studied laccase-based systems reflected in the different degradation profiles of pulps after treatment. TGA showed laccase to modify the thermal degradation path of the initial pulp, increasing the proportion of cellulose degrading at low temperature. The addition of SLD resulted in virtually no change of the thermal degradation path of the initial pulp, indicating that the laccase–SLD system basically exerted its action on the lignin component of fibers. In contrast to SLD, FRC was found to significantly increase the amount of the paracrystalline fraction of cellulose, probably as a consequence of its incorporation into fibers. The presence of TEMPO, especially under those conditions boosting the oxidative functionalization, was found to cause an intense degradation of cellulose and the formation of a substantial amount of amorphous cellulose degrading at low temperature. A novel aspect of the laccase–TEMPO system was identified in this work: its ability to reduce the hexenuronic acids (HexA) content content of pulp, under specific reaction conditions.

Paper strength improvement by oxidative modification of sisal cellulose fibers with laccase–TEMPO system: Influence of the process variables

The oxidation of sisal pulp fibers by the laccase–TEMPO system was investigated and the influence of process variables including the laccase and TEMPO doses, and reaction time, on various properties of the oxidized fibers and of handsheets made from them was for the first time assessed using a three-variable statistical plan. The laccase–TEMPO system was found to oxidatively modify cellulose fibers, largely by introducing aldehyde groups and, to a much lesser extent, by introducing carboxyl groups. Based on the mathematical models used, increasing the TEMPO dose and reaction time increases the aldehyde content of the fibers, thereby also increasing their wet strength by effect of inter-fiber covalent bonding via hemiacetal linkages. Although no accurate model for the carboxyl content could be established, this property was found to peak under the specific conditions yielding the highest response in the dry tensile index model. The fact that the oxidative treatment diminished pulp viscosity is indicative of partial depolymerization of cellulose. This was especially marked under the conditions providing the highest contents in aldehyde and carboxyl groups, and the greatest improvements in the dry and wet tensile indices.

Controlling the moisture absorption capacity in a fiber-reinforced thermoplastic starch using sodium trimetaphosphate

A novel biodegradable material derived from thermoplastic potato starch was prepared with intended uses in high moisture environments where its high water sorption characteristics are beneficial, such as wound dressing, transdermal patches or food packaging. A modified composite was prepared for this purpose by reactive extrusion whereby potato starch and 2.5–25% (w/w) sisal cellulose fibers were compounded together in the presence of 2.7% (w/w) sodium trimetaphosphate. The fibers were included to increase the wet strength of the material. A low degree of substitution (0.088–0.113) was sought by bound phosphate groups with anionic character in order to overcome a reduction in moisture absorption capacity resulting from fiber incorporation, yet being insufficient to cause embrittlement via crosslinking. The results showed the approach has sufficient merit to minimize the influence of the hydrophobic fibers on the water absorption capacity of the starch material but adhering to so low of a degree of substitution could not fully prevent a reduction. The results also suggested that the fibers may have participated in the crosslinking reaction.

Wet strength development in sisal cellulose fibers by effect of a laccase–TEMPO treatment

The aim of this study was to investigate the oxidation of sisal pulp fibers by laccase–TEMPO system which had never previously been examined. High cellulose content sisal fibers were treated with laccase from Trametes villosa and a varying amount of TEMPO in order to evaluate the potential of laccase–TEMPO system to improve the paper physical properties of pulp fibers. The effect of the oxidative treatment on the carboxyl group content and viscosity of pulp fibers was examined. The resulting papers were analyzed in terms of strength-related properties, water absorbency capabilities and fiber morphology. Oxidation of sisal pulp by laccase–TEMPO system resulted in a very important improvement of wet strength of the resulting papers, suggesting the formation of a substantial amount of aldehyde groups in cellulose chains providing interfiber bonding through hemiacetal linkages.