Pre-treatment of Flax Fibers for use in Rotationally Molded Biocomposites

Abstract

Flax fibers can be used as environmentally friendly alternatives to conventional reinforcing fibers (e.g., glass) in composites. The interest in natural fiber-reinforced polymer composites is growing rapidly due to its high performance in terms of mechanical properties, significant processing advantages, excellent chemical resistance, low cost and low density. These advantages place natural fiber composites among the high performance composites having economic and environmental advantages. In the field of technical utilization of plant fibers, flax fiber-reinforced composites represent one of the most important areas. On the other hand, lack of good interfacial adhesion and poor resistance to moisture absorption make the use of natural fiber-reinforced composites less attractive. In order to improve their interfacial properties, fibers were subjected to chemical treatments, namely, mercerization, silane treatment, benzoylation, and peroxide treatment. Selective removal of non-cellulosic compounds constitutes the main objective of the chemical treatments of flax fibers to improve the performance of fiber-reinforced composites. The objective of this study was to determine the effects of pre-treated flax fibers on the performance of the fiber-reinforced composites.Short flax fibers were derived from Saskatchewan-grown flax straws, for use in fiberreinforced composites. Composites consisting of high-density polyethylene (HDPE) or linear low-density polyethylene (LLDPE) or HDPE/LLDPE mix, chemically treated fibers and additives were prepared by the extrusion process. Extrusion is expected to improve the interfacial adhesion significantly as opposed to simple mixing of the two iii components. The extruded strands were then pelletized and ground. The test samples were prepared by rotational molding. The fiber surface topology and the tensile fracture surfaces of the composites were characterized by scanning electron microscopy to determine whether the modified fiber-matrix interface had improved interfacial bonding.Mechanical and physical properties of the composites were evaluated. The differential scanning calorimetry technique was also used to measure the melting point of flax fiber and composite.Overall, the scanning electron microscopy photographs of fiber surface characteristics and fracture surfaces of composites clearly indicated the extent of fiber-matrix interface adhesion. Chemically treated fiber-reinforced composites showed better fiber-matrix interaction as observed from the good dispersion of fibers in the matrix system. Special thanks to my graduate committee Charles Maulé, the chair, for providing a motivating and enthusiastic environment during the many discussions and his helpful feedback and suggestions. The critique of this thesis by Dr. Chris Zhang, external examiner, is acknowledged.

Characterization of Flax Water Retting of Different Durations in Laboratory Condition and Evaluation of Its Fiber Properties

“…where D is the linear density of the fiber (mg/m or tex), W is mass (mg), and L is fiber length (m) (Wang et al 2007). …”

Impact and flexural properties of flax fabrics and Lyocell fiber-reinforced bio-based thermoset

“…The laser machine was of model Laserpro Spirit, 50 -W sealed CO 2 , DC Servo control, and work area of 860 Â 460 mm 2 . The Lyocell composite specimens were all cut in the carding direction and composite type A was cut in the thicker yarn direction.…”

Effects of Steaming and Steam Explosion on Mechanical Properties of Snake Fruit (Salacca) Fiber

“…Furthermore, chemical treatment with a solution containing a silicon group is called silane treatment [3] [4] [6]. Next chemical treatment using a solution containing chloride group is called benzoylation treatment [4]. Further treatment process conditions can be done by adjusting the concentration of the solution, temperature, time, stirring, and pH.…”

“…Chemical treatment of natural fibers can be done by soaking or dipping into solution (solution) group containing hydroxide (OH) [3] [4], silica (Si) [3] [4] [5] [6], chloride (Cl) [4] and other coatings group, along with the treatment process conditions. Methods of treatment with a solution of alkali hydroxide are commonly called alkali treatment [3] [4]. Furthermore, chemical treatment with a solution containing a silicon group is called silane treatment [3] [4] [6].…”