Lignocellulosic fiber processing techniques

The Musaceae family has significant potential as a source of lignocellulosic fibres and starch from the plant’s bunches and pseudostems. These materials, which have traditionally been considered waste, can be used to produce fully bio-based composites to replace petroleum-derived synthetic plastics in some sectors such as packaging, the automotive industry, and implants. The fibres extracted from Musaceae have mechanical, thermal, and physicochemical properties that allow them to compete with other natural fibres such as sisal, henequen, fique, and jute, among others, which are currently used in the preparation of bio-based composites. Despite the potential use of Musaceae residues, there are currently not many records related to bio-based composites’ developments using starches, flours, and lignocellulosic fibres from banana and plantain pseudostems. In this sense, the present study focusses on the description of the Musaceae components and the review of experimental reports where both lignocellulosic fibre from banana pseudostem and flour and starch are used with different biodegradable and non-biodegradable matrices, specifying the types of surface modification, the processing techniques used, and the applications achieved.

Lignocellulosic fibers or their derivatives may be used to reinforce packaging materials. The aim of this study was to assess the effect of adding microcrystalline cellulose (MCC) on the microstructure and properties of thermoplastic starch (TPS)/poly(butylene adipate-co-terephthalate) (PBAT) films. MCC concentrations of 0, 1, 3 and 5 g 100 g−1 TPS/PBAT were added to mixtures containing 56 g 100 g−1 of TPS and 44 g 100 g−1 of PBAT. The morphology of the film changed slightly and the storage modulus increased when MCC was added at the concentration of 3 g 100 g−1 TPS/PBAT. No differences were observed in the Fourier transform infrared spectra and in the crystallinity of the films without and with 3 g MCC 100 g−1 TPS/PBAT. The tensile strength (medium value 6.52 MPa), elongation at break (medium value 723.83 %) and water vapor permeability (WVP; medium value 5.68 × 10−11 g m−1 s−1 Pa−1) of the films with and without MCC showed no significant differences. The films with 3 and 5 g MCC 100 g−1 TPS/PBAT were stiffer than control film. The low interaction of MCC with the polymer matrix (mainly with PBAT), the processing technique, and the low concentration of MCC may have contributed to these results.

The global demand for wood as a building material is steadily growing, while the availability of this natural resource is diminishing. This situation has led to the development of alternative materials. Of the various synthetic materials that have been explored and advocated, polymer composites claim a major participation as building materials. There has been a growing interest in utilizing natural fibres as reinforcement in polymer composite for making low cost construction materials in recent years. Natural fibres are prospective reinforcing materials and their use until now has been more traditional than technical. They have long served many useful purposes but the application of the material technology for the utilization of natural fibres as reinforcement in polymer matrix took place in comparatively recent years. Economic and other related factors in many developing countries where natural fibres are abundant, demand that scientists and engineers apply appropriate technology to utilize these natural fibres as effectively and economically as possible to produce good quality fibre reinforced polymer composites for housing and other needs. Among the various natural fibres, sisal is of particular interest in that its composites have high impact strength besides having moderate tensile and flexural properties compared to other lignocellulosic fibres. The present paper surveys the research work published in the field of sisal fibre reinforced polymer composites with special reference to the structure and properties of sisal fibre, processing techniques, and the physical and mechanical properties of the composites.

Natural fibres are a good reinforcing material. Among the various natural fibres, sisal fibre is of particular interest, since its composites have high impact strength besides having moderate tensile and flexural properties compared to other ligno-cellulosic fibres. Sisal fibre is a promising reinforcement for use in composites on account of its low cost, low density, high specific strength and modulus, no health hazards, easy availability in some countries and renewability. The present work focused on the recent developments in the field of sisal fibre reinforced phenol formaldehyde composites with reference to the properties of sisal fibre, processing techniques, and the physical and mechanical properties of the composites. The mechanical properties of the composites show much improvement by the addition of sisal fibre of optimum fibre length 40 mm and fibre loading 54 wt%. The better fibre matrix interaction is shown by sisal-PF containing 54 wt%. The comparison with other natural fibres shows that sisal fibre is a good reinforcing agent in PF matrix. Flexural strength and impact strength of the composites were examined and are increased with increasing the fibre content. Ageing studies of the composites showed a similar trend to that of un-aged samples. Interestingly, water absorption test results show that composite with 54 wt% fibre loading have good interaction with the matrix and contains less voids.

Potential of lignocellulosic fiber reinforced polymer composites for automobile parts production: Current knowledge, research needs, and future direction

Cellulose is the most abundant natural polymer on earth. It is the major constituent of cotton and wood, which together are the basic resources for all cellulose based products such as paper, textiles, construction materials, etc. Cellulose is also used as raw material for the production of blends, composites and nanocomposites which have a variety of different applications. In this chapter we review the main characteristics and properties of cellulose as well as its most promising potential applications emphasizing the use of composites reinforced with lignocellulosic fibers, nanocomposites reinforced with cellulose whiskers and bacterial cellulose nanocomposites. First, we start describing the structure and properties of cellulose at the molecular, supramolecular and morphological level. We present a review of cellulose whiskers, including the main processing techniques used for their preparation, as well as the influence of the processing conditions on the characteristics of such whiskers. We continue describing the manufacture of cellulose based blends, composites and nanocomposites. Composites reinforced with lignocellulosic macro-fibers as well as nanocomposites reinforced with cellulose whiskers and bacterial cellulose nanofibers are reviewed in this section. Finally, we present several applications for cellulose based composites and nanocomposites. This last section includes biomedical, optoelectronic and electrical applications as well as the use of cellulose for the preparation of high strength “nanopapers” and materials for packaging applications.KeywordsBacterial CelluloseSilk FibroinCellulose NanocrystalsCellulose NanofibersRegenerate Cellulose FiberThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The production of composites and materials based on nanocellulose has attracted considerable attention in the last few decades since their abundance, renewability, high strength and rigidity, environmental friendliness, and low weight are all unmissable and potentially useful. This analysis deals with crucial factors in the manufacture of nanocellulose composites and presents and explores different composite processing techniques. Rare combinations of features and new design opportunities are seen in high-performance nanocomposites. Their potential is so high that their utility in different fields, ranging from packaging to biomedicine, with an annual growth rate projected at around 25% and a standardized summary emphasizes the need for such products, their methods of fabrication, and several recent studies on structure, properties and potential applications. There is a focus on the possible use of naturally occurring materials like clay-based minerals, chrysotile and lignocellulose fibers. In this chapter, an overview of nanocomposites is deliberated in detail and the nanocomposite applications provide new technology and business options for different industries in the aerospace, vehicle, electronics, electrical and biomedical engineering sector as they are naturally friendly. <br>

The interest in natural fiber-reinforced polymer composites is growing rapidly due to their high performance in terms of mechanical properties, significant processing advantages, excellent chemical resistance, low cost and low density. In this study, the compression and injection molding of polypropylene (PP) and polylactic acid (PLA) based composites reinforced with rice hulls or kenaf fibers was carried out and their basic properties were examined. Rice hulls from rice processing plants and natural lignocellulosic kenaf fibers from the bast of the plant Hibiscus Cannabinus represent renewable sources that could be utilized for composites. Maleic anhydride grafted PP (MAPP) and maleic anhydride grafted PLA (MAPLA) were used as coupling agents (CA) to improve the compatibility and adhesion between the fibers and the matrix. Composites containing 30 wt % reinforcement were manufactured by compression and injection molding, and their mechanical and thermal properties were compared. It was found that the techniques applied for manufacturing of the eco-composites under certain processing conditions did not induce significant changes of the mechanical properties. The flexural strength of the compressed composite sample based on PP and kenaf is 51. 3 MPa in comparison with 46.7 MPa for the same composite produced by injection molding technique. Particularly, PP-based composites were less sensitive to processing cycles than PLA-based composites. The experimental results suggest that the compression and injection molding are promising techniques for processing of eco-composites. Moreover, the PP-based composites and PLA-based composites can be processed by compression and injection molding. Both composites are suitable for applications as construction materials.

This article presents the results of modeling the properties of wood composite board materials without binders, made on the basis of unwashed lignocellulose fibers activated by steam explosion treatment. The experimental technique is described, as well as the technique for determining the physical properties of the obtained board materials. The paper presents mathematical processing of experimental data on the properties of wood composite board materials (density), carried out in accordance with the method of parametric identification of statistical models of multidimensional experiments in the CurveExpert 1.4 software environment. This technique is used to process experimental data with obtaining mathematical expressions in exponential and demonstrative form (less often in linear), the laws of which have physical meaning, in contrast to polynomial models obtained as a result of regression analysis. A three-dimensional statistical model of the influence of molding pressure and pressing temperature on the density and strength of wood composite board materials based on unwashed activated fibers has been compiled. The research results showed that the pressing temperature and molding pressure contribute to an increase in the density and strength of the samples. The simulation results have shown the effectiveness of the parametric identification method, which makes it possible to obtain models of the dependence of the output quantities on a variety of factors, while the models have a low relative error and are written using mathematical constructs that have physical meaning. The final errors for multivariate models of the density of WCM from unwashed samples are: The absolute error of the model is 31.7 kg/m3, and the relative error of the model is 1.91%. A similar technique for modeling technological processes can underlie the design and technological support of machine-building industries for wood processing technologies.KeywordsWood composite material (WCM)Steam explosion treatmentUnwashed activated fibersSlab materialDensityParametric identification

Investigation of a lignocellulose fiber hornification treatment for improving the functionality of apple pomace-based pulp for molded pulp packaging