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Melt mixed polypropylene/polyamide 6 (PA6) and multiwalled carbon nanotubes (CNTs) were molded by compression, injection, and interval injection molding. PA phase exists as an isolated dispersed phase in the sea–island system with different phase orientations and dispersion degrees. CNTs prefer to be located in the minor PA phase because of their remarkable compatibility. However, when the content of CNTs is high enough, a conductive path can be formed regardless of the phase morphology. Moreover, when the CNT content is low, the dispersed PA forms an unelongated structure, which is beneficial to electrical conductivity. Although the elongated PA phase holds advantages in terms of its tensile properties, its conductivity network is defective. These results were proposed to uncover the influence of dispersed phase morphology on mechanical and electrical conductivity. [ABSTRACT FROM AUTHOR]

Agro‐industrial residue from sugarcane cultivation in Brazil generates more than 200 million tons of bagasse per year, which is rich in plant fibers that can be potentially applied in polymer composites. New processing routes are required to process composites with fiber contents above 50% wt. The objective of this work was to incorporate sugarcane bagasse fibers to polypropylene at high contents (50%–80% wt) in the development of composites via thermokinetic mixture. Composites with 50% and 60% fibers showed a traditional composite morphology, while those with 70% and 80% resembled agglomerated composites. The water absorption varied between 5% and 34%, increasing with fiber content, while the bulk density remained relatively constant, close to 1 g/cm3. The flexural strength and the flexural modulus reached 31 MPa and 2.4 GPa, respectively, tending to decrease with fiber content. In summary, the present work showed the viability of the proposed processing route, with only two starting materials, to produce cheap, relatively lightweight composites with mechanical properties close to and water absorption much lower than wood composites (medium‐density fiberboard and medium‐density particleboard) used in similar applications, such as furniture, construction, and automobile industry. [ABSTRACT FROM AUTHOR]

The glass syntactic polypropylene composite highlights as the most used wet thermal insulation solution for subsea pipelines. The continuous and disperse phases of the material, however, show low interaction levels due to poor chemical compatibility between the polypropylene matrix and the hollow glass microspheres, ultimately leading to a premature failure when subjected to mechanical loads. This article assesses the use of poly(propylene‐g‐maleic anhydride) and ethylene‐acrylic ester‐glycidyl methacrylate terpolymer as compatibilizing agents to enhance the matrix–filler interaction. The effectiveness of the selected strategy is analyzed through mechanical stress–strain tests, evaluation of absorbed water during hot water immersion, and evaluation of thermal properties. The composites with polypropylene and heterophasic polypropylene matrices, 25% by the weight of hollow glass microspheres, and contents of compatibilizing agents spanning from 1% to 5% by weight were prepared and tested. The addition of compatibilizers increased the tensile strength by 9%–30% and reduced the elongation at break by 13% to 45%. Thermal analyses indicated no significant influence of compatibilizers on melting points and crystallization temperatures; meanwhile, water absorption studies indicated opposite effects of each compatibilizer on the absorbed water content. Finally, the main results observed were ratified through scanning electron microscopy. [ABSTRACT FROM AUTHOR]