Environmentally Intelligent Biocomposites (original) (raw)

Fully biodegradable polylactic composites reinforced with bleached softwood fibers

2016

The increasing environmental awareness of the society has led to the development of materials with a lower environmental impact. Polylactic acid (PLA) is a biodegradable polymer with higher mechanical properties than PP. The scientific literature shows some interest in PLA reinforced biocomposites, but the published mechanical properties of such materials are comparatively low. In fact, the generation of a good interface, when the reinforcement contents are higher than 30%, is nowadays unsolved. The main objective of this study is to obtain PLA biocomposites with a good interface and with satisfactory improvements in their mechanical properties against reinforcement contents. Bleached pine fibers, used as reinforcement, were prepared and shred with 1/3 and 2/3 of diglyme, in order to avoid the formation of hydrogen bonds among the cellulose fibers. Then, composite materials were obtained through kinetic mixing. The composites were injection molded to make standard specimens and were...

Mechanical, Thermal And Biodegradable Properties Of Bioplast-Spruce Green Wood Polymer Composites

2018

Environmental and sustainability concerns push the industries to manufacture alternative materials having less environmental impact. The Wood Plastic Composites (WPCs) produced by blending the biopolymers and natural fillers permit not only to tailor the desired properties of materials but also are the solution to meet the environmental and sustainability requirements. This work presents the elaboration and characterization of the fully green WPCs prepared by blending a biopolymer, BIOPLAST® GS 2189 and spruce sawdust used as filler with different amounts. Since both components are bio-based, the resulting material is entirely environmentally friendly. The mechanical, thermal, structural properties of these WPCs were characterized by different analytical methods like tensile, flexural and impact tests, Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD). Their water absorption properties and resistance to the termite and fungal attac...

PLA/wood biocomposites: Improving composite strength by chemical treatment of the fibers

Composites Part A: Applied Science and Manufacturing, 2013

A resol type phenolic resin was prepared for the impregnation of wood particles used for the reinforcement of PLA. A preliminary study showed that the resin penetrates wood with rates depending on the concentration of the solution and on temperature. Treatment with a solution of 1 wt% resin resulted in a considerable increase of composite strength and decrease of water absorption. Composite strength improved as a result of increased inherent strength of the wood, but interfacial adhesion might be modified as well. When wood was treated with resin solutions of larger concentrations, the strength of the composites decreased, first slightly, then drastically to a very small value. A larger amount of resin results in a thick coating on wood with inferior mechanical properties. At large resin contents the mechanism of deformation changes; the thick coating breaks very easily leading to the catastrophic failure of the composites at very small loads.

Study of the Properties of a Biodegradable Polymer Filled with Different Wood Flour Particles

2020

Lignocellulosic wood flour particles with three different sizes were used to reinforce Solanyl® type bioplastic in three compositions (10, 20, and 30 wt.%) and further processed by melt-extrusion and injection molding to simulate industrial conditions. The wood flour particles were morphologically and granulometric analyzed to evaluate their use as reinforcing filler. The Fuller method on wood flour particles was successfully applied and the obtained results were subsequently corroborated by the mechanical characterization. The rheological studies allowed observing how the viscosity was affected by the addition of wood flour and to recover information about the processing conditions of the biocomposites. Results suggest that all particles can be employed in extrusion processes (shear rate less than 1000 s−1). However, under injection molding conditions, biocomposites with high percentages of wood flour or excessively large particles may cause an increase in defective injected-parts ...

Multi-component Polymer Systems Comprising Wood as Bio-based Component and Thermoplastic Polymer Matrices – An Overview

BioResources, 2018

The production of wood-based polymer composites has gained increasing interest in recent years, especially regarding sustainability issues, aiming at the recovery, reuse, and up-cycling of by-products from natural resources exploitation, as well as plastics. Due to their reduced cost, low density, and availability, wood components (fibers, flour) are attractive fillers for thermoplastic polymer matrices used in multi-component systems. Performance of wood-based thermoplastic materials mainly depends on the type and strength of interactions at the polymer-wood interface. Different low polarity polymers (high/low density polyethylene, polypropylene, polyvinylchloride) can be successfully used as matrices in such formulations. Various methods may be applied in order to obtain specified performance attributes of wood-based composites. Addition of appropriate compatibilizing agents, chemical and/or physical modification of the filler in order to improve its compatibility towards the matrix, or a judicious combination of these approaches may be employed. This paper briefly reviews some recent literature data, as well as research results by the authors, aiming at a comparative assessment of the materials properties (structure, thermal, mechanical and water sorption behavior) in correlation with the nature and type of components, processing, recycling options, and environmental impact.

Valorization of Waste Wood Flour and Rice Husk in Poly(Lactic Acid)-Based Hybrid Biocomposites

Journal of Polymers and The Environment, 2022

This study explores the possibility of developing a new class of hybrid particulate-filled biocomposites using wood flour and rice husk wastes as environmentally friendly additives to poly(lactic acid) (PLA) as matrix material. Samples were prepared with fillers of different concentrations (0, 2.5, 5, 7.5 and 10 wt %), while the ratio of wood flour and rice husk was fixed at 1:1 in all cases. The preparation of biocomposites was performed through extrusion using a twin-screw extruder. Subsequently, they were formed into specimens by injection molding. Mechanical, thermal, thermomechanical, and morphological properties were examined. The addition of natural waste particles resulted in a remarkable improvement both in tensile and flexural modulus; however at a cost of impact strength and tensile strength. Meanwhile, flexural stress at conventional strain values were barely affected by the presence of wood flour and rice husk. The SEM images confirmed that there is a limited interfacial adhesion between the components, which supports the results obtained during mechanical tests. Both the differential scanning calorimetry (DSC) and the dynamic mechanical analysis indicated that the glass transition temperature of PLA was not affected by the incorporation of filler particles; however, the crystalline structure was gradually altered with increasing filler loading according to the DSC. Additionally, the particles were observed acting as nucleating agents, thereby increasing the overall crystallinity of PLA.

Man-Made and Natural Fibres as a Reinforcement in Fully Biodegradable Polymer Composites: A Concise Study

Journal of Polymers and the Environment

Biodegradable and ecologically friendly polymer materials attract great attention of many scientific groups in the world as they fit well in the sustainable development policy and are considered to be "a right thing to do" by the general public. Such polymers can be modified by the addition of different fillers, favorably of natural origin. In the paper we provide a comparison between composites based on two biodegradable polymers: poly(lactic acid)-biodegradable, natural stock polymer and poly(butylene succinate)-biodegradable polymer produced from fossil based materials. For each polymer we have prepared a series of composites with different fibres (natural: hemp and flax, and manmade: Cordenka) and different filler loadings. To fully characterize obtained materials thermal, mechanical and surface free energy measurements were performed, completed with morphology observations and an attempt to compare the experimental data for tensile measurements with values obtained using the modified rule of mixtures. The tensile results calculated using the modified rule of mixture for below 30% fibre loading are found to be fitting the experimental data. Composites mechanical properties and morphology were strongly affected by the type of fibre used and its loading, however thermal properties remained almost unchanged. In specific, Cordenka fibres tend to form bunches which presence greatly influences the mechanical properties but still our studies have shown clear advantage of manmade Cordenka fibres over the hemp and flax fibres when considering distribution and fibre-polymer interaction.