Mechanical and Thermal Properties of Polypropylene Composites Reinforced with Lignocellulose Nanofibers Dried in Melted Ethylene-Butene Copolymer

Abstract

Lignocellulose nanofibers were prepared by the wet disk milling of wood flour. First, an ethylene-butene copolymer was pre-compounded with wood flour or lignocellulose nanofibers to prepare master batches. This process involved evaporating the water of the lignocellulose nanofiber suspension during compounding with ethylene-butene copolymer by heating at 105 °C. These master batches were compounded again with polypropylene to obtain the final composites. Since ethylene-butene copolymer is an elastomer, its addition increased the impact strength of polypropylene but decreased the stiffness. In contrast, the wood flour- and lignocellulose nanofiber-reinforced composites showed significantly higher flexural moduli and slightly higher flexural yield stresses than did the ethylene-butene/polypropylene blends. Further, the wood flour composites exhibited brittle fractures during tensile tests and had lower impact strengths than those of the ethylene-butene/polypropylene blends. On the other hand, the addition of the lignocellulose nanofibers did not decrease the impact strength of the ethylene-butene/polypropylene blends. Finally, the addition of wood flour and the lignocellulose nanofibers increased the crystallization temperature and crystallization rate of polypropylene. The increases were more remarkable in the case of the lignocellulose nanofibers than for wood flour.

Using Triaxial Tests to Determine the Shearing Strength of Geogrid-Reinforced Sand

“…The tensile modulus of the PP is about 1.2 GPa; in another source, it is given as 1.3-14.9 GPa. [37,38] The PLAXIS 3D program contains models for the linear and nonlinear behavior of structural elements. The authors of this paper chose the linear behavior for geogrid elements.…”

Impact modification of PP/wood composites: A new approach using hybrid fibers

“…Above 30 wt% wood content brittle fracture was observed even if as much as 50 wt% of elastomer was added to the composites. Iwamoto et al [34] prepared wood flour and lignocellulose nano fiber reinforced PP composites and investigated their impact modification with ethylene-butylene copolymers. Although impact resistance increased with the addition of the copolymers in both cases, the actual values of notched Izod impact strength were below that of any commercial three-component PP composite.…”

Multi-step pretreatment as an eco-efficient pretreatment method for the production of cellulose nanofiber from oil palm empty fruit bunch

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