This paper investigates the utilization of commercial masterbatches of graphene nanoplatelets to improve the properties of neat polymer and wood fiber composites manufactured by conventional processing methods. The effect of aspect ratio of the graphene platelets (represented by the different number of layers in the nanoplatelet) on the properties of high-density polyethylene (HDPE) is discussed. The composites were characterized for their mechanical properties (tensile, flexural, impact) and physical characteristics (morphology, crystallization, and thermal stability). The effect of the addition of nanoplatelets on the thermal conductivity and diffusivity of the reinforced polymer with different contents of reinforcement was also investigated. In general, the mechanical performance of the polymer was enhanced at the presence of either of the reinforcements (graphene or wood fiber). The improvement in mechanical properties of the nanocomposite was notable considering that no compatibilizer was used in the manufacturing. The use of a masterbatch can promote utilization of nano-modified polymer composites on an industrial scale without modification of the currently employed processing methods and facilities.

Continuous metalized regenerated cellulose fibers for advanced applications (e.g., multi-functional composites) are produced by electroless copper plating. Copper is successfully deposited on the surface of cellulose fibers using commercial cyanide-free electroless copper plating packages commonly available for the manufacturing of printed wiring boards. The deposited copper was found to enhance the thermal stability, electrical conductivity and resistance to moisture uptake of the fibers. On the other hand, the chemistry involved in plating altered the molecular structure of the fibers, as was indicated by the degradation of their mechanical performance (tensile strength and modulus).

The deformation of polymers at constant applied stress is one of their major drawbacks, limiting their use in advanced applications. The study of this property using classical techniques requires extensive testing over long periods of time. It is well known that reinforced polymers show improved behavior over time compared to their neat counterparts. In this study, the effect of adding different amounts of graphene nanoplatelets (GNPs) on the time‐dependent properties of high‐density polyethylene (HDPE) is investigated using short‐term creep tests and load/unload recovery tests. The results are discussed in terms of the test profile and the influence of loading history. Viscoplasticity/viscoelasticity analysis is performed using Zapas model and by comparing creep, creep compliance and pure viscoelasticity curves. The results show that the reinforcement of 15 wt% GNP have the most significant effect on the time‐dependent behavior, reducing the strain by more than 50%. The creep compliance curves show that nano‐reinforced HDPE behaves nonlinearly viscoelastically even at very low stresses. In addition to demonstrating the effect of nano‐reinforcement, the discussion of the results concludes that the influence of loading history can be quite significant and should not be neglected in the design and evaluation of material behavior.

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