Chapters authored
Viscoelastic Performance of Biocomposites
The viscoelastic behavior and performance to creep of biocomposites made from fique natural fiber and low-density polyethylene-aluminum (LDPE–Al) obtained from recycled long-life packages were studied. A relationship was observed between the creep mechanical responses of biocomposites with respect to natural fibers. Additionally, the four and six parameters of the mathematical model were calculated from the creep curves. A very good agreement between the experimental data and the theoretical curves was obtained in the fluency region. The relationship between interfacial fiber or filler and the polymer matrix is an indicator of mechanical performance of biocomposite, regardless of the application that you want to give. It is known that the mechanical and viscoelastic properties depend on the application time of loading, the type of load, temperature, micromechanics relationship between the natural fiber and the matrix, the type of anchor prevailing for the transfer effort to micro- and nano-levels and cannot be treated mathematically only by the laws of solids or fluids, viscoelastic behavior of biocomposites. It is possible to obtain mathematical models that fit different rheological phenomena; for example, creep and stress relaxation can be modeled and correlated with biocomposite experiment using dynamic mechanical analysis (DMA).
Part of the book: Composites from Renewable and Sustainable Materials
Biocomposites from Colombian Sugarcane Bagasse with Polypropylene: Mechanical, Thermal and Viscoelastic Properties
Biocomposites are materials formed by mixing a polymer matrix and a filler or reinforcement, with the characteristic that at least one should be of biological origin. For this study, biocomposites were obtained from natural fibers of cane bagasse and polypropylene, using bagasse from postindustrial sources, originating from the production of sugarcane from the Valle-Cauca region in Colombia. In addition, cane bagasse fibers were treated chemically, with the purpose of improving the interfacial relationship. Polypropylene homopolymer was used as a polymeric matrix, which was mixed in a twin screw extruder, obtaining different materials as biocomposites. Finally, it was possible to obtain a suitable biocomposite for application in injection molding processes and studying its mechanical, viscoelastic, and thermal behaviors, through DSC, TGA, DMA, and SEM techniques.
Part of the book: Characterizations of Some Composite Materials
Recycled Polypropylene-Coffee Husk and Coir Coconut Biocomposites: Morphological, Mechanical, Thermal and Environmental Studies
In this work, biocomposites based on recycled polypropylene (r-PP) and two different natural fibers (coffee husk-CHF and coconut coir-CCF fibers) were prepared using extrusion and injection molding processes. Also, the addition of maleated polypropylene (MAPP) as a coupling agent on the biocomposites was explored. Recycled polypropylene and its biocomposites were tested following ASTM standards in order to evaluate tensile and flexural mechanical properties. Also, thermal behavior and the morphology of these materials have been studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electronic microscopy (SEM). The experimental results showed that the addition of CHF and CCF to the r-PP resulted in an increase in the flexural modulus and thermal properties of the composites but resulted in poor impact properties. Thermal characterization showed that CHF possesses a better thermal stability compared to CCF. However, both fibers act as nucleating agents and generate an increase in the thermal stability of the r-PP phase. Finally, it was observed that addition of 4% of MAPP significantly improved the mechanical strength and impact behavior of the biocomposites. Regarding environmental issues, a cradle to gate life cycle assessment was made in order to define the carbon footprint of the materials.
Part of the book: Thermosoftening Plastics