This paper presents a preliminary study on obtaining and characterization of phenolic resin-based composites modified with nanometric silicon carbide. The nanocomposites were prepared by incorporating nanometric silicon carbide (nSiC) into phenolic resin at 0.5, 1 and 2 wt% contents using ultrasonication to ensure uniform dispersion of the nanopowder, followed by heat curing of the phenolic-based materials at controlled temperature profile up to 120 • C. The obtained nanocomposites were characterized by FTIR spectroscopy and scanning electron microscopy analysis and evaluated in terms of mechanical, tribological and thermal stability under load. The results highlight the positive effect of the nanometric silicon carbide addition in phenolic resin on mechanical, thermo-mechanical and tribological performance, improving their strength, stiffness and abrasive properties. The best results were obtained for 1 wt% nSiC, proving that this value is the optimum nanometric silicon carbide content. The results indicate that these materials could be effectively used to obtain ablative or carbon-carbon composites in future studies.

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EPDM/hemp fiber composites with fiber loading of 0–20 phr were prepared by the blending technique on a laboratory electrically heated roller mill. Test specimens were obtained by vulcanization using a laboratory hydraulic press. The elastomer crosslinking and the chemical modification of the hemp fiber surface were achieved by a radical reaction mechanism initiated by di(tert-butylperoxyisopropyl)benzene. The influence of the fiber loading on the mechanical properties, gel fraction, swelling ratio and crosslink degree was investigated. The gel fraction, crosslink density and rubber–hemp fiber interaction were evaluated based on equilibrium solvent-swelling measurements using the Flory–Rehner relation and Kraus and Lorenz–Park equations. The morphology of the EPDM/hemp fiber composites was analyzed by scanning electron microscopy. The water absorption increases as the hemp fiber loading increases.

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This paper presents the production of carbon-fiber-fabric-reinforced laminated composites based on a polyamide 6 matrix using a multiple-stages technique that involves polymer dissolution in formic acid followed by fabric impregnation and high-temperature pressing. The polyamide/solvent ratio's influence on the interface and mechanical properties is discussed, analyzing three PA6 weight contents of (10, 20, and 30) % in a formic acid solvent. The mechanical behavior of the obtained laminated composites is evaluated using tensile and 3-point bending tests and the fracture cross-section is analyzed using microscopy investigation techniques in order to evaluate the fiber-matrix interface and the composite fracture mechanism. The results show that the best mechanical performance is obtained when using a solution of 20 % mass fraction of polyamide in formic acid, as this leads to the formation of a uniform polymer layer that is able to completely embed the fibers that constitute the fabric and create a strong mechanical interface within the composite. Keywords: polyamide 6, carbon fiber, mechanical properties, polymer/solvent ratio, mechanical interfacê lanek predstavlja izdelavo laminatnega kompozita na osnovi poliamida 6, oja~anega s tkanino iz ogljikovih vlaken, z uporabo ve~stopenjske tehnike, ki vklju~uje raztapljanje poliamida v mravljin~ni kislini ter impregnacijo tkanine in stiskanje pri visoki temperaturi. Razlo`en je vpliv razmerja poliamid/topilo na stik in mehanske lastnosti, z analizo treh masnih vsebnosti PA6 (10, 20, 30) % v mravljin~ni kislini. Mehansko obna{anje dobljenega laminiranega kompozita je ocenjeno z nateznim preizkusom in s 3-to~kovnim upogibnim preizkusom, presek preloma pa je analiziran z mikroskopsko tehniko, da bi ocenili stik z vlaknato osnovo in mehanizem preloma kompozita. Rezultati ka`ejo, da je najbolj{a mehanska zmogljivost dose`ena pri uporabi raztopine z 20 % masnim dele`em poliamida v mravljin~ni kislini, ker to povzro~i nastanek enakomernega polimernega sloja, ki lahko popolnoma obda vlakna tkanine in ustvari mo~an mehanski stik v kompozitu. Klju~ne besede: poliamid 6, ogljikovo vlakno, mehanske lastnosti, razmerje polimer/topilo, mehanski stik