Are Natural-Based Composites Sustainable?

Abstract

This paper assesses the aspects related to sustainability of polymer composites, focusing on the two main components of a composite, the matrix and the reinforcement/filler. Most studies analyzed deals with the assessment of the composite performance, but not much attention has been paid to the life cycle assessment (LCA), biodegradation or recyclability of these materials, even in those papers containing the terms “sustainable” (or its derivate words), “green” or “eco”. Many papers claim about the sustainable or renewable character of natural fiber composites, although, again, analysis about recyclability, biodegradation or carbon footprint determination of these materials have not been studied in detail. More studies focusing on the assessment of these composites are needed in order to clarify their potential environmental benefits when compared to other types of composites, which include compounds not obtained from biological resources. LCA methodology has only been applied to some case studies, finding enhanced environmental behavior for natural fiber composites when compared to synthetic ones, also showing the potential benefits of using recycled carbon or glass fibers. Biodegradable composites are considered of lesser interest to recyclable ones, as they allow for a higher profitability of the resources. Finally, it is interesting to highlight the enormous potential of waste as raw material for composite production, both for the matrix and the filler/reinforcement; these have two main benefits: no resources are used for their growth (in the case of biological materials), and fewer residues need to be disposed.

Polymer Composite Fabrication Reinforced with Bamboo Fiber for Particle Board Product Raw Material Application

“…Polyester-SBT composites show a different behavior; in the graph of stress to strain, there is no necking, but after reaching the maximum stress, it immediately breaks. The comparison between the graph of the tensile and the bending test results for t condition of the material with the type of bamboo, particle size, and volume fraction s give the same material behavior (see Figures 6,7,11,and 12). The relationship betwe stress and strain from tensile test and bending test results on SBT-polyester composit gives similar profiles; namely, the stress increases linearly with increasing length, a there is no necking behavior but immediately breaks.…”

“…Mechanically, bamboo fiber has high tensile strength (140-800 MPa) and a high modulus of elasticity (33 GPa) with a low density of 0.6-0.8 g/cm 3 [7]. The specific properties of bamboo fiber, such as low specific gravity, specific strength, and stiffness, are comparable to glass fiber [8][9][10][11].…”

Enhanced aging resistance of poly(ε-caprolactone)/brewers’ spent grain composites

“…From an economic and, most of all, environmental point of view, the most beneficial is incorporating waste--based fillers, which are not used in other applications [2][3][4]. Such an approach enables a noticeable reduction of the environmental impacts of polymer composites, which was indicated by multiple works dealing with the waste-based fillers for wood-polymer composites [5][6][7]. Sommerhuber et al [8] investigated the manufacturing of HDPE/wood polymer composites from virgin and secondary raw materials.…”

A Brief Review on the Influence of Ionic Liquids on the Mechanical, Thermal, and Chemical Properties of Biodegradable Polymer Composites

“…There are many applications of biodegradable polymer composites; some of them have been employed in food packaging, textile, and tissue engineering applications [ 32 , 33 ]. Moreover, the incorporation of inorganic fillers into biodegradable polymers can influence the mechanical properties and hydrophobicity of the fabricated composites, which are very important for biomedical applications [ 34 ].…”