Biocomposite Materials

In recent years, research on environmentally sustainable packaging has been gaining momentum, primarily driven by consumer ecological consciousness. Green biocomposites play an important role in novel and innovative materials for the emerging sustainable packaging industry, being intrinsically biobased and biodegradable. Therefore, the following chapter is aimed to make an overview of the main trends on green biocomposites study and development, their environmental impact and their importance in future production systems. A revision of the polymeric matrices and fillers most widely used for green biocomposites and bionanocomposites manufacture is done, and the results of the latest investigations on the subject are discussed. Besides, their role in active and intelligent packaging is reviewed as well as their implementation for 3D printing technologies. Finally, the relevance of these materials study and development in terms of environmental impact is herein considered, remarking the importance of adequate life cycle assessment of the developed green biocomposites in comparison to conventional materials used for similar packaging applications.

The application of non-renewable building materials including concrete and metals in construction industries have caused a major impact on the environment including the destruction of more than 45% of the global resources, the consumption of 35% of energy and nearly 40% of energy-related emissions (UN Secretary-General’s High-Level Panel on Global 2012). In order to help in reducing these extending impacts, the building sector started considering three reduction of these dreadful impacts through increasing the environmentally-friendly building materials with Natural Fiber Reinforced Polymer Composites (NFRP), specially through WPCs (Wood Polymer Composites) since the 90s. The use of natural fibers in composites form in the building sector is historically applied since the phrase time when straw and mud were mixed to form the first known bricks in history. After the discovery of cement, it became the largest dominant material in the industry till our current time, in spite of its huge environmental damage. Natural fibres (NF) have been mostly applied in non-structural applications. Accordingly, this paper discusses applying reinforcement scenarios in the form of novel core and veneer reinforcement to enhance a load-bearing capacity to reach to improved mechanical properties that could enable building a demo- shell construction system. In this research natural fiber reinforced polymer composite (NFRP) produced from agricultural residues in the form of straw fibres (SF) mixed with three different types of polymers including (polylactide (PLA), a TPE (Thermoplastic elastic polymer) and high-density polyethylene (HDPE)) were developed through extrusion processes, then laminated or veneered to elevate the material properties needed to be reached to apply in load-bearing structures. The thermoplastic elastic polymers (TPE) were applied to enhance elasticity and flexibility in reaching sophisticated geometries. The mechanical strength was controlled by veneering. The targeted and reached material properties were applied in structural simulations that were later used in predicting the structural performance of a physical experimental shell construction that were built to validate the settled hypothesis of reinforcement of elastic/semi-elastic lignocellulosic cores to be applied in load-bearing systems. The paper will highlight the material samples development and testing, followed by an analysis and interpretation to the possibility of usage and appliance in load-bearing structures. Finally, the physical built demonstrator in the form of the experimental shell construction is shortly illustrated to showcase the validity of the settled hypothesis.

Poly(lactic acid) (PLA) is the most common synthetic biopolymer that is derived from renewable resources and is biodegradable. PLA is used for commodity and specialized applications such as medical implants. Low processing temperatures, good mechanical and thermal stability and ability to obtain PLA in different configurations and structures make it an ideal biopolymer. However, PLA has several limitations, primarily, relatively poor resistance to chemicals. Several modifications have been done to improve the performance and properties of PLA and its products. Developing biocomposites by blending PLA with other biopolymers, nanomaterials including nanoclay have been done. Biocomposites have been developed by blending polysaccharides such as cellulose, starch, chitin and also proteins with PLA. Transparent and high performance biocomposites useful for food, medical and other applications have been developed from the blends. Despite numerous approaches, there are several limitations of PLA based biocomposites which presents scope for further research and development.

The demands of modern society are increasingly driving a shift from nonrenewable petroleum-based materials to more sustainable renewable resources. As the most prevalent natural polymer on Earth, cellulose has attracted broad interest for use as a green additive or replacement for unsustainable petroleum-based materials. The cellulose polymer arranges naturally into microscale semi-crystalline cellulose fibrils which can be degraded, typically by chemical treatments, to yield the nanoscale crystalline region of the cellulose polymer. These nanoscale crystals display a high aspect ratio with length from 100 to 3000 nm and width from 3 to 50 nm. They also possess excellent mechanical properties, comparable to high cost synthetic reinforcing nanomaterials such as carbon nanotubes. The morphology of these cellulose nanocrystals (CNCs) is highly dependent on natural cellulose source material and the utilized CNC preparation conditions. When utilizing CNC as a reinforcing filler material within a polymer matrix, the resulting nanocomposite often displays properties dependent on the morphology of the filler. This chapter discusses the benefits, drawbacks and differences between CNC sources with focus on the resulting CNC morphology and its effect on the mechanical properties of CNC containing polymeric nanocomposites. In addition, recent findings in the area of hybrid multifiller CNC reinforced polymeric nanocomposites will be highlighted and contrasted with monofiller CNC polymeric nanocomposites.

Bio-based polymer composites have been introduced as the most promising alternatives for the petroleum-based polymer composites, owing to the depletion of fossil fuel resources, global energy crisis and growing concerns about environmental pollutants. Among them, the green biocomposites totally based on plants, which consist of lignocellulosic fibers as reinforcement agents and biopolymers as matrices, have many beneficial advantages in a wide range of applications such as availability, renewability, eco-friendly, biodegradability and low density. The most frequently used green composites are the plant fiber-reinforced poly(lactic acid) (PLA) biocomposites. Regardless to the sustainability and ecologically friendly properties, PLA/plant fiber biocomposites must be modified to gain a comparable performance with the petroleum-based composites. Different chemical, physical, physio-chemical and biological modification methods have been developed to treat the lignocellulosic fibers for improving the matrix/filler interfacial adhesion and biocomposite final properties. Through the literature, the most widely applied methods are the fiber chemical modifications. In this chapter, the effects of different chemical treatments of plant fibers, as the most feasible modification processes, in the PLA-based biocomposites have been discussed and the importance of choosing proper reaction conditions on controlling the biocomposite performance is clarified.

In last few years, there is a constant demand from several industrial fields for using light-weight components to exhibit high mechanical performance. This demand is met by employing composite materials, especially the fiber reinforced polymer composites. Compare to conventional process shape complexity, infill density, and manufacturing lead times are no longer barriers with additive manufacturing. Therefore, the fabrication of light weight fiber reinforced polymeric composites using additive manufacturing remains the protagonist. In this chapter different types of fiber reinforce composites developed using different additive manufacturing technique are classified based on the length of fiber, aspect ratio, orientation and performance i.e. short, long and continuous fiber reinforced composites. Further the type of continuous natural fiber reinforced composites that are developed using various additive manufacturing technique such as fused deposition modelling (FDM) or Fused Filament Fabrication (FFF), stereolithography (SLA), selective laser sintering (SLS), selective laser melting (SLM), and Direct ink writing (DIW) were reviewed and discussed. In addition, different materials, drawbacks, and strengths associated with different additive manufacturing processes were detailed. Few examples were also presented in the chapter were the 3D Printed structural components has its own real time application in various manufacturing sectors namely automotive, aerospace and aviation.

Generally, defects by word have been determined as abnormality, imperfection, shortcoming, and flaw that impairs quality, function or utility of the materials or system. In manufacturing, the defects or specifically called manufacturing defects are very significant influence for many other properties and performance of the material or system. In literature, manufacturing defects in natural fibre reinforced composites that normally occur during fabrication are classified as misaligned fibres, pockets of undispersed cross-linker, poor wetted resin, resin-rich zone, and voids. The knowledge and determination on manufacturing defect occurrences is important and helps the researcher or manufacturer improve the quality of fabrication process of material and materials performance. This chapter discusses manufacturing defects that have been recognized occurred during the manufacturing process of natural fibre reinforced composite materials by using a non-destructive technique as Optical Microscope (OM) and Scanning Electron Microscopy (SEM). The comeback of manufacturing defects to internal and external fields dictate in many ways of the material properties and performance of final product.

The chapter represents a comprehensive review of inorganic particles reinforced the ultra-high molecular weight polyethylene (UHMWPE) to promotes better operational properties as compared to pure UHMWPE for orthopaedic applications. A strong interfacial adhesion between UHMWPE matrix-based particle filler is believed to be the major factor influencing the UHMWPE based composite material’s properties outcome. Hence, graphene oxide and graphite were reviewed as the potential reinforcement particles due to its special additional properties; biocompatible, high thermal conductivity, hydrophilic behavior and could act as a nucleating agent, which rarely found in other type of materials in current market. UHMWPE based carbon-based reinforced composite with optimum processing parameters and wt% shows improved mechanical properties. UHMWPE reinforced cabon-based particle exhibited remarkable mechanical properties which have the potential to be the alternative materials for joint orthopaedic applications.

Bio-polymer-based composite has experienced remarkable growth in engineering applications over the last few years. Due to the growing awareness and understanding of environmental concerns, many researchers are interested in finding the best ways to replace existing products that have adverse effects on both the environment and human beings. Since the trends are increasing every year, the uses of natural fibers have become a priority in many industrial sectors and engineering applications because of its biodegradability, low cost materials, low energy usage and renewable resources. Poly (lactic acid) (PLA) is an eco-friendly biodegradable polymer with intrusive qualities such as renewable and compostable. Several studies have been carried out on natural fiber reinforced PLA bio-composite, but there is still no comprehensive review on water absorption behavior of natural fiber reinforced PLA composites. Since water absorption is one of major concern for outdoor applications of bio-composite, this study will be focusing on water absorption properties of natural fiber reinforced PLA composites.

The traffic and transportation of wood products around the world is one of the causes that have facilitated the migration of pathogens and insects between countries. These biological invasions have resulted in the destruction of plant species, causing significant economic and ecological losses in many parts of the world. To this end, the World Trade Organization, through the International Plant Protection Convention Working Group, has established a standard for phytosanitary measures (ISPM 15), which requires that wood products (pallets, packaging, etc.) be treated according to this standard. It is within this framework that this chapter is included and aims to present a numerical approach to quantify the time required for microwave phytosanitary treatment of wood products. For this purpose, the microwave heat conduction equation is expressed in terms of volumetric enthalpy and numerical resolution is achieved using the finite element method. As an application, we considered three Canadian wooden. For the analysis, we considered a frequency of 2466 MHz, temperatures from −20 to +20 °C and a moisture content of 131%.

Nanocomposites are divided into 3 main types namely metals, ceramics and polymers. Apart from that, there are various methods in the production of nanoceramic, namely mechanical, vapor, high temperature and gel solution. Normally, gel solution was use for low cost and easy for handling. Characterization of nanocomposite can be done using various methods either by use the reaction of electrons, ions or radiation. Each characterization will give different features of nanocomposite either in term or surface, element or other characteristic of nanocomposite. Apart from that, nanocomposite is one of the biomaterial materials suitable for use in vivo or even in vitro and also has antibacterial properties. All this factor will enhance the suitability of nanocomposite to be use in engineering field and other related industry.

A combination of bioactive scaffold with drug delivery of therapeutic agents is a great deal to locally treat bone infections. However, controllable drug release behaviours for different types of drug-incorporated scaffold have been not comprehensively compared. In this study, novel technique was proposed with the addition of bioactive agents in microspheres was incorporated into carbonate apatite (CO₃Ap) scaffold. A simple slurry-dipping method by dispersion of 0.8 wt% suspension of gentamicin (GEN)-loaded polylactic acid (PLA) microsphere (GENMS) using an ultrasonic bath was used to coat the scaffold. GENMS was fabricated by double emulsion. This coated scaffold was compared to the GEN coated scaffold without microsphere and uncoated scaffold with direct loading of GEN. It was confirmed that the microsphere coating did not inhibit the apatite growth of the scaffold when immersed in Hank’s Balance Salt Solution for 4 weeks. The drug release profile exhibited the initial burst and sustained drug release could be improved by the presence of GENMS in the coated scaffold. Moreover, the kinetic release study supported the findings of different drug release based on zero-order, first-order, Higuchi and Korsmeyer–Peppas models. The results showed that drug release mechanisms were diffusion and degradation controlled for scaffold, while for coated scaffolds led to diffusion and degradation of chitosan and microsphere. Rougher surface of the scaffold by the adhered GENMS on the scaffold facilitated cell proliferation. In short, this multifunctional coated bioactive scaffold has the potential to enhance cell attachment and provide local of controlled drug delivery for bone tissue engineering improvement.