Flammability Performance of Biocomposites and Bionanocomposites

Table of Contents

1. Frontmatter

2. Introduction to Flammability Tests and Fire Retardant Mechanisms of the Biocomposites and Bionanocomposites

   M. Ramesh, S. Ganeshkumar, A. Felix Sahayaraj, J. Maniraj

   Abstract

   This research review article provides a comprehensive overview of flammability tests and fire retardant mechanisms specific to biocomposites and bionanocomposites. As the demand for sustainable materials in various industries grows, the investigation of fire safety becomes imperative. The article begins by elucidating the fundamental principles of flammability tests, addressing key methodologies employed to assess the fire resistance of biocomposites and bionanocomposites. Subsequently, the discussion delves into the intricate mechanisms underlying the fire retardancy of these bio-based materials. Emphasis is placed on exploring the inherent properties and synergistic effects of incorporating fire retardants within these composite structures. Through a systematic review of current research findings, this article aims to consolidate knowledge in the field, aiding researchers, practitioners, and industries in making informed decisions regarding the application of fire safety measures in the context of sustainable and environmentally friendly materials. The synthesis of information presented in this review contributes to advancing the understanding of flammability characteristics and fire mitigation strategies for biocomposites and bionanocomposites.

3. Fire Retardant Properties of the Epoxy Resin-Based Biocomposites and Bionanocomposite

   Emel Kuram

   Abstract

   Epoxy resins have great modulus, high glass transition temperature, superb adhesion to large variety of fibers and chemical resistance. But the fact that epoxy resin cannot be recycled or dispersed due to permanent cross-linked structure causes them not environmentally friendly. Therefore, reinforcing biopolymers or synthetic polymers via natural fibers in place of synthetic ones within polymeric composites is good option for environmental improvement. There is increasing attention for natural fiber-reinforced composites at industrial implementations as natural fibers are appealing alternative to synthetic fibers. But, since natural fibers possess high flammability, fire behavior of the material needs to be enhanced. Fire retardant properties of polymer composites is a significant matter when environment, public health and safety are concerned. This chapter presents an overview on fundamentals for fire retardancy properties of epoxy resin based biocomposites and bionanocomposites. Tests that are utilized to evaluate flammability of epoxy resin based biocomposites and bionanocomposites and their results are reviewed.

4. Phenolic and PLA Based Natural Fiber Reinforce Composite: A Fire Performance Analysis

   Durgesh Kumar Mishra, Nitish Kumar, Santosh Kumar

   Abstract

   In order to produce products based on composites, researchers have recently made a significant effort to find environmentally safe and biodegradable reinforcements. The increasing usage of biomaterials in recent times has significantly reduced carbon footprints and greenhouse gas emissions. As a result, the use of natural fiber reinforcement in polymer matrices is highly recommended due to its exceptional ability to balance processing convenience and performance with cost. The low fire resistance and delayed flammability behavior of these materials, limit the application of natural fiber composite for different potential applications. Consequently, it follows that in order to create natural composite with improved thermal degradation, biodegradation, and fire resistance, it is critical to comprehend the flammability and degradation of natural composite as well as the testing procedures used to evaluate them. Hence, in this review, we will present the detailed analysis of fire performance of phenolic and PLA based reinforced polymer composite. In particular, UL-94 horizontal and vertical flammability tests and cone calorimetric analysis was presented the utmost dominant methods for evaluating the fire performance behavior of the natural fiber-reinforced composites.

5. Flammability Properties of the Polyester Resin-Based Biocomposites and Bionanocomposites

   Mahmut Ali Ermeydan

   Abstract

   Composites used in construction, rail, and maritime industries frequently use polyester resin cross-linked with styrene. However, the inclusion of biofibers and volatile styrene makes polyester resin-based biocomposites and bionanocomposites susceptible to fire. Strict fire safety laws are also necessary because biocomposite components are heat-and fire-sensitive. Numerous flame-retardant treatments and methods, such as layered silicates, nanofillers, halogenated and non-halogenated flame-retardants, and chemical changes such copolymerization or grafting, have been developed to solve this problem. Green biocomposites have undergone some improvement in their heat resistance by physical and chemical treatment, but they still don’t match the strict fire safety standards. In order to improve flame retardancy techniques, find more appropriate and environmentally friendly flame-retardants, and choose suitable natural fibers and biopolymers for the development of fire-safe biocomposite products, a thorough investigation into the thermal breakdown and fire behavior of green biocomposites is required. In this chapter, the research done over the last decades on flammability of polyester biocomposites and some recent research on the reduction of flammability of biocomposites and bionanocomposites are reviewed.

6. Flammability Performance of the Graphene-Infused Sisal/Epoxy and Hemp/Epoxy Composites

   Preet Parashram Harer, K. Balaji, Muthukumar Chandrasekar, S. Jeyanthi, K. Senthilkumar, T. Senthil Muthu Kumar, R. Sundaramoorthy

   Abstract

   In this experimental work, the flammability performance of sisal/epoxy and hemp/epoxy composites infused with graphene nanocomposites at varying weight percentages was studied. The composite samples were fabricated using the hand lay-up technique, and the samples were subjected to the UL-94 test in both vertical and horizontal directions. The results revealed that sisal/epoxy samples exhibited a V-1 rating, which was attributed to the absence of dripping. However, the hemp/epoxy samples showed dripping, and resulted in a V-2 rating. Further, the burn time ranged from 170 to 210 s for all composite samples. A decrease in burn time was observed for all sisal-based composite samples with varying graphene content, whereas hemp-based samples exhibited a significant reduction in burn time only at 3 wt% of graphene. Based on these observations, sisal-based composite samples can be proposed for fire-sensitive applications due to their superior flammability resistance behavior.

7. Flame Retardancy Characteristics of the Polypropylene-Based Biocomposites and Bionanocomposites

   Lin Feng Ng, Mohd Yazid Yahya, Chandrasekar Muthukumar, Jyotishkumar Parameswaranpillai, Sanjay Mavinkere Rangappa, Suchart Siengchin

   Abstract

   Composite materials have received significant attention from researchers and engineers over the past decades. With several fascinating merits offered by composite materials, the steady growth of such materials in various engineering sectors has been witnessed. However, one of the critical weaknesses of most composite materials is associated with their poor fire retardancy properties, which lead to material decomposition and the release of toxic substances upon burning. When dealing with biocomposites incorporated with cellulosic fibers, it is particularly vital to understand their fire retardancy potential as these materials are generally highly flammable. Since biocomposite materials have been employed in various engineering applications, it is essential to improve their fire retardancy to lessen the risk of catastrophic failure. This chapter intends to provide a comprehensive understanding of the combustion mechanism and the techniques for enhancing the flame retardancy of composite materials. In addition, this chapter also aims to delve deeper into the flammability of cellulosic fibers, flame retardancy of biocomposites and eco-friendly flame retardants that have immense potential to develop flame-retardant biocomposites. This chapter is expected to enhance the understanding of the readers by providing a comprehensive overview of the fire retardancy of biocomposites.

8. Flammability Performance of the HDPE and LDPE Biocomposites and Bionanocomposites

   Konstantinos G. Gatos

   Abstract

   HDPE and LDPE composites are considered in various applications in everyday life. The need for a sustainable future suggests a low environmental impact of the composites in use throughout their life cycle. In this view, the reduction in carbon dioxide emissions can be approached by exploiting biocomposites and bionanocomposites. Consequently, natural fibers play a key role in such a product design. Current standards in critical sectors such as construction and transportation require, among others, high levels of fire resistance. Therefore, polyethylene biocomposites should also successfully meet the relevant stringent criteria. In this book chapter, several strategies which are advancing the flammability performance of the HDPE and LDPE biocomposites and bionanocomposites are discussed.

9. Flammability Characteristics of Additively Manufactured ASA/Nylon Polymer Blends: Influence of Blend Ratios

   Eekshit, Muthukumar Chandrasekar, Wadie Sultan, Lin Feng Ng, S. Jeyanthi, V. Parthasarathy, K. Senthilkumar, T. Senthil Muthu Kumar

   Abstract

   Polymer blend consists of two or more polymers blended together to form a material that combines the advantage of the individual base materials. In this work, the polymer blend coupons based on the nylon filament and Acrylic Styrene Acrylonitrile (ASA) were developed. The blends with various proportions of ASA and nylon created from the extrusion process and fused deposition modeling were subjected to UL-94 flammability test (vertical burn and horizontal burn). According to the results from this study, blending nylon with ASA improved the flame retardancy. The blends, regardless of the proportion of nylon, exhibited superior flame retardancy marked by a lower flame propagation rate and higher burn time than ASA. Increasing the nylon content also increased the elapsed burn time for the blend in the case of the vertical and horizontal burn test.

10. Enhancing Flame Resistance of Castor Oil-Based Flexible PU Foam Through Silica Hydrogel Coating

    Vinoth Kumar Selvaraj, Jeyanthi Subramanian, Vijayakumar Rajendran, S. Raja, Thangapandi Muneeswaran, S. Vignesh, K. Anto Kumar

    Abstract

    The study investigates the creation of flame-retardant flexible polyurethane foam (PU) made from castor oil (CO) in varying densities. This naturally flammable foam is treated using a dip coating process with concentrated hydrochloric acid (HCl) and sodium silicate to form a protective silica hydrogel layer, thereby enhancing its fire resistance. The characterization of the foam was done through thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. Evaluation through the underwriter’s laboratory (UL) 94 ratings and burning rate measurements demonstrated significant enhancements. Intriguingly, while non-coated foam samples received V-2 ratings, the coated counterparts exhibited markedly higher ratings of V-1 and V-0, highlighting their superior flame resistance. Specimen (S3) demonstrates greater performance, exhibiting a burning rate of 6.72 mm/min in vertical conditions and 6.16 mm/min in horizontal conditions. Notably, this sample displays a notable difference of 0.56 mm/min between its vertical and horizontal burning rates, indicating its consistent and commendable fire resistance across varying orientations. Findings revealed a direct link between foam density, burning rate, and increased flame retardancy. This innovative approach holds immense promise for an array of applications across consumer and commercial sectors, including but not limited to furniture, carpet underlay, bedding, automotive interiors, and packaging. This research lays the groundwork for creating safer and more durable materials for a range of everyday products by utilizing sustainable resources and advanced flame-retardant techniques.

11. Flammability Performance of the Natural Fiber-Reinforced Hybrid Composites

    Thanh Mai Nguyen Tran, Van-Ta Do, Quang Thang Do, Xiem Nguyen Thang, M. N. Prabhakar, Jung-il Song

    Abstract

    The chapter critically reviews the potentials of various natural fibers on the fire-resistance behavior of biocomposites and bionanocomposites. It evaluates the potential of fibers like cotton, hemp, and bamboo for flame retardation in combination with the different matrix materials and is assessed for its interaction. Material combinations and hybridization strategies of the examples given in this chapter are synergistically influential in enhancing the fire performance. It also deals with developments in natural fiber technologies with its persistent challenges on sustainability and environment-oriented issues. Future research recommendations are concerned with technological advances in composites reinforced using natural fibers. The highlighted main development covers much safer materials which are environmentally more sustainable with better flame resistance.

12. Fire-Retardant Properties of the Styrene-Butadiene Rubber-Based Biocomposites and Bionanocomposites

    Nurjannah Salim, Siti Noorbaini Sarmin, Siti Noorhidayah Mustapha

    Abstract

    This chapter provides a comprehensive review of recent advances in flame retardant of styrene-butadiene rubber (SBR), with a particular focus on biocomposites and bionanocomposites. Due to the complexity of materials with increasing demand, SBR is emerging as a promising matrix suitable for its versatile properties. The incorporation of natural fibers, fillers, and nanofillers into SBR matrices has shown the ability to enhance flame retardant properties by maintaining mechanical properties. Furthermore, this chapter will emphasize synergistic effects, fire-retardant additives, and thermal stability processes. A discussion of the future views is also included in this chapter. The purpose of this discussion is to provide direction for future attempts to develop products that are long-lasting and have improved fire safety qualities.

13. Flammability Characteristics of the Silicone Rubber-Based Biocomposites and Bionanocomposites

    V. M. Gobinath, V. Parthasarathy, P. Senthil Kumar, T. Arivazhagan

    Abstract

    The materials with the chemical composition of higher levels of carbon, hydrogen, and oxygen are often more combustible than those with the lower levels of these elements. The flammability qualities of SR biocomposites are greatly influenced by the loading of nanofillers and the composition of the fillers. The flammability properties of the materials and the measurement of flammability by various testing methods are discussed in detail. The flammability measurement techniques like oxygen index test, smoke density test, and test for fire propagation are highlighted in this chapter. The ignition temperature, smoke production rate, and release of any flammable gas or vapor during combustion must be taken into account while assessing the flammability of the materials. The flammability properties and the flammability measurement using various testing methods are discussed in detail. The chapter also outlines the flammability measurement techniques like the UL94 test, oxygen index test, smoke density test and fire propagation test with the aim of providing insightful information on a material’s flammability and fire behavior. The reinforcing effect of natural fillers like montmorillonite (MMT), sepiolite, and silica on the flame retardancy of silicone rubber biocomposites is also summarized.

14. Synergistic Effects of Flammability Performance of the Hybrid Composites Reinforced with the Various Natural Fibers

    Swagata Dutta, Avishek Chanda, Vikram Yadama

    Abstract

    Natural fiber-reinforced polymeric composites (NFRPCs) possess excellent potential for effective applications in many applications for various industries. There are significant advantages of using these materials over synthetic fibers, which apart from being biodegradable and environment-friendly also include excellent weight-to-stiffness and strength-to-stiffness ratios, low densities and light-weight structures, abundant availability, and others. Some of the limitations do include strength compared to their synthetic polymers, an aspect that has been widely addressed through hybridization. Additionally, natural fibers have traditionally faced issues regarding their flammability performance, limiting their applications where heat exposures are on the higher end. Natural fiber-reinforced hybrid composites also have similar issues, and therefore, it is imperative to observe and study the thermal properties and decomposition of the constituent fibers, polymers, and the derived composite under heat and fire. Another advantage of hybridization is also the ability to increase the fire performance of NFRPCs. The current chapter will primarily focus on the thermal behavior of the constituent of hybrid NFRPCs and the fire reaction and resistance properties of their composites, which can be used in both structural and non-structural applications within the built environment.

15. Post-Fire Response of the Composite Facesheet Used in the Main Rotor Blades: A Case Study

    S. I. Dhaniya Lakshmi, G. Samiksha, G. Ramesh Babu, Muthukumar Chandrasekar, Naveen Jesuarockiam, N. Karthikeyan

    Abstract

    A case study on the post-fire performance of the facesheet extracted from the sandwich structure of a helicopter rotor blade is presented. The facesheet of the composite sandwich was exposed to heating through oxyacetylene flame only on its top face replicating a real-life fire scenario. Load bearing ability under tension and bending were affected such that the post-fire specimens possessed inferior residual tensile strength. The flame exposure created rougher surface morphology and increased oxygen elemental concentration from the EDX spectra. As the flame exposure temperature was increased, a significant increase in glass transition temperature and shifting of loss modulus as well as tan delta peaks were observed as per the dynamic mechanical analysis (DMA). The flame exposed specimens were also marked by the major decline storage modulus indicating the severity of fire exposure.