Tuning the performance of PA6/EPDM‐MA nanocomposites reinforced with Ni_0.5Zn_0.5Fe₂O₄. Effect of the mixing protocol on mechanical, thermal, thermomechanical, magnetic, and morphological behavior

Abstract

The mixing protocol effect was investigated in nanocomposites based on polyamide 6 (PA6) and maleic anhydride grafted ethylene-propylene-diene (EPDM-MA), using Ni-Zn ferrite as filler. The nanocomposites were processed using an internal mixer and specimens were injection molded. Compounds properties were investigated through Izod impact strength, tensile strength, x-ray diffraction (XRD), magnetic measurements, differential scanning calorimetry (DSC), thermogravimetry (TG), heat deflection temperature (HDT), and scanning electron microscopy (SEM). PA6/EPDM-MA mixture showed super-tough behavior, with an increase of around 918% in impact strength, compared with PA6. However, there was a loss close to 50% in the elastic modulus and 5% in HDT, due to the high flexibility. In view of this, this mixture was selected for the production of nanocomposites toughened with Ni-Zn ferrite, using three mixing sequences. When the nanocomposite was processed by the simultaneous mixing of all components (PA6/EPDM-MA/Ni-Zn), the highest impact strength (458 J/m) was reached, corresponding to a gain of 486%, compared with PA6. On the other hand, when Ni-Zn ferrite and PA6 were initially premixed by melting, before EPDM-MA addition in a second processing step, HDT and impact strength properties increased by 6% and 281%, in relation to PA6. In addition, the nanocomposites showed magnetic responses, with a soft material behavior, that is, they magnetize and demagnetize easily. In general, toughened and magnetic nanocomposites were produced, with good mechanical and thermal properties, displaying potential to produce magnetic films.

Do descarte ao reaproveitamento do resíduo de estireno-butadieno (SBRr): produção de compostos de PA6/SBRr compatibilizados com SEBS-MA e reforçados com argila montmorilonita

“…A PA6 possui funcionalidade inerente por meio dos grupos terminais aminas, o que a torna um polímero excelente para reações de enxertia durante o processamento no estado fundido (Gao et al, 2022;Zhao et al, 2020). Copolímeros funcionalizados com anidrido maleico têm sido apresentados como compatibilizantes efetivos para misturas de PA6, já que os grupos anidridos maleico são capazes de reagir com os grupos terminais amina da PA6 (Luna et al, 2022b;Wu et al, 2015). A Figura 1 apresenta às curvas de reometria de torque da PA6 e dos sistemas PA6/SBRr e PA6/SBRr/SEBS-MA, com e sem argila CLNa.…”