Effect of Carbon Nanostructures and Fatty Acid Treatment on the Mechanical and Thermal Performances of Flax/Polypropylene Composites

Abstract

Four different strategies for mitigating the highly hydrophilic nature of flax fibers were investigated with a view to increase their compatibility with apolar polypropylene. The effects of two carbon nanostructures (graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs)), of a chemical modification with a fatty acid (stearic acid), and of maleated polypropylene on interfacial adhesion, mechanical properties (tensile and flexural), and thermal stability (TGA) were compared. The best performance was achieved by a synergistic combination of GNPs and maleated polypropylene, which resulted in an increase in tensile strength and modulus of 42.46% and 54.96%, respectively, compared to baseline composites. Stearation proved to be an effective strategy for increasing the compatibility with apolar matrices when performed in an ethanol solution with a 0.4 M concentration. The results demonstrate that an adequate selection of surface modification strategies leads to considerable enhancements in targeted properties.

Experimental and finite element analysis of the impact response of agglomerated cork and its intraply hybrid flax/basalt sandwich structures

“…The first mass drop occurs between 320 °C and 380 °C and causes a reduction of almost 25 % due to flax fibers thermal degradation whereas the second mass drop of 35 % takes place between 420 °C and 490 °C and must be ascribed to PP thermal degradation. These results are in perfect agreement with the ones reported by Khalfallah et al [194] who identified flax thermal degradation between 270 °C and 380 °C, by Biagiotti et al [195] who studied flaxpolypropylene composites and detected flax degradation between 355 °C and 360 °C and PP degradation at 460 °C and by Russo et al [196] who investigated the effect of carbon nanotubes and stearic acid treatment on flax-polypropylene composites and found out flax thermal degradation between 340 °C and 360 °C and PP degradation between 380 °C and 470 °C. 32, in particular Figure 151 shows the curves of the first heating and cooling cycle for both PP and PPC skins, whereas Table 32 summarizes melting and crystallization temperatures and the degree of crystallinity calculated according to Equation (4.1):…”

Potential Natural Fiber Polymeric Nanobiocomposites: A Review

“…A carbon nanotube (CNT) is considered an excellent nanomaterial for modifying the natural fiber surface through increasing the compatibility between the biofiber and polymer in the matrix. Besides, the polymeric materials used in BC materials should have an excellent resistance against the damage from any mechanical deformation, thermal instability, and chemical change to be suitable for space or automotive industries; in this regard, CNT could be an ideal selection, requiring very little loading as a prominent nanofiller [162][163][164]. CNT is a very good candidate for enhancing the interfacial mechanical strength in the NBC, due to its superior thermal and mechanical properties [165].…”

Manufacturing of bio-polyamide 11/basalt thermoplastic laminates by hot compaction: The key-role of matrix rheology

“…20 Scarce fiber-matrix affinity further complicate the delicate impregnation phase, making necessary chemical treatments of the fibers or functionalization of the matrix to enhance the interfacial adhesion. [21][22][23] The processing challenges related to the high viscosities of thermoplastic polymers could discourage the use of this class of matrices , 24 and focused studies to tackle this issue are particularly desirable. In this context, a good starting point to describe fabric impregnation is the Darcy's law, which expresses the flow of a fluid through a porous medium.…”