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This research aimed to evaluate the influence of styrene–butadiene–styrene (SBS) compatibilizer in the polystyrene blends properties with a recycled styrene–butadiene rubber compound. The SBS content was 5, 7.5, and 10%. Commercial high-impact polystyrene (HIPS) was used for comparison. The results indicated that the viscosity of the blends was higher than that of HIPS. The blends compatibilized with 5 and 7.5% had the same level of impact strength as HIPS, while the one with 10% obtained a gain of 80% in relation to HIPS. The flexural strength, hardness, heat deflection temperature, and Vicat softening temperature properties were similar to those of HIPS, which was attributed to the presence of inorganic fillers, minimizing losses in these properties. By atomic force microscopy, two distinct phases were observed, and in the morphology analyzed through scanning electron microscopy, a typical characteristic of immiscible blends was observed.

The aim of the present work is to evaluate the effect of NaOH solution as a stress cracking agent on the thermal and tensile properties of PET and PET/ZnO composites. The solutions were applied during tensile testing and the effects were monitored by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and testing the actual mechanical properties. The rate of crystallization was increased when the samples were exposed to NaOH, as observed by both cold and melt crystallization; this is possibly due to the reduction in molar mass of the PET molecules caused by NaOH. During melting, the DSC peaks became more complex, which is probably due to the distinct macromolecular mass, as well as crystallites with different sizes and levels of perfection. According to TGA analyses, no drastic changes were observed on the thermal stability of PET due to the action of NaOH. The tensile properties were shown to decrease drastically upon exposure to NaOH, which is the main symptom of stress cracking, leading to increased fragility, as also observed in the scanning electron microscopy (SEM) images. The presence of ZnO improved PET crystallization and provided some protection against the harmful effects of NaOH.

Polypropylene (PP) blends with acrylonitrile‐butadiene‐styrene (ABS) were prepared using the styrene‐ethylene‐butylene‐styrene copolymer (SEBS) as a compatibilizing agent. The blends were prepared in a co‐rotational twin‐screw extruder and injection molded. Torque rheometry, Izod impact strength, tensile strength, heat deflection temperature (HDT), differential scanning calorimetry, thermogravimetry, and scanning electron microscopy properties were investigated. The results showed that there was an increase in the torque of PA6/ABS blends with SEBS addition. The PP/ABS/SEBS (60/25/15%) blend showed significant improvement in impact strength, elongation at break, thermal stability, and HDT compared with neat PP. The elastic modulus and tensile strength have not been significantly reduced. The degree of crystallinity and the crystalline melting temperature increased, indicating a nucleating effect of ABS. The PP/ABS blends compatibilized with 12.5% and 15% SEBS presented morphology with well‐distributed fine ABS particles with good interfacial adhesion. As a result, thermal stability has been improved over pure PP and the mechanical properties have been increased, especially impact strength. In general, the addition of the SEBS copolymer as the PP/ABS blend compatibilizer has the advantage of refining the blend's morphology, increasing its toughness and thermal stability, without jeopardizing other PP properties.

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In this work, PA6/EPDM-MA was added as an impact modifier for highperformance polypropylene (PP) production. PA6/EPDM-MA compounds were processed in an internal mixer, aiming at chemical reaction between maleic anhydride of EPDM-MA and the amine terminal groups of PA6. Afterward, PP/(PA6/EPDM-MA) blends were processed by extrusion and injection molding. Rheological properties were evaluated using torque rheometry; additionally, Fourier transform infrared spectroscopy, Molau test, impact and tensile strengths, Shore D hardness, thermal deflection temperature, X-ray diffraction, differential scanning calorimetry, thermogravimetry, water absorption, contact angle, and scanning electron microscopy tests were performed in injected specimens. PP/(PA6/EPDM-MA) with 70/(15/15)% displayed quite high increase in impact and elongation at break, with gains of 850% and 265%, compared to neat PP. There were no drastic losses in tensile strength, elastic modulus, and Shore D hardness, due to PA6 addition. A significant increase was seen in the thermal stability of PP/(PA6/EPDM-MA), corroborating the increase in structural stability seen in HDT. SEM images showed high interfacial adhesion between PP and PA6/EPDM-MA corroborating higher mechanical properties.Summing up, PA6/EPDM-MA premix acted as an efficient impact modifier for PP. Acquired data show that P6/EPDM-MA system was effective in developing high-performance PP with potential for application in the automotive and electronics industries.high-performance blends, PP/(PA6/EPDM-MA), reactive processing | INTRODUCTIONPolypropylene (PP) is one of the most common industrially applied polymers, mainly due to its low cost, low density, good thermal properties, excellent processability, and reasonable mechanical properties. [1][2][3] However, PP displays low impact strength, which limits its higher performance applications [4] ; hence, PP must be toughened to expand the range of its properties. [5] Toughness is a quite useful parameter that determines whether a given

The vulcanized rubber waste from the shoe industry causes environmental damage when it is incinerated or inappropriately discarded, turning this into a problem of major concern. Therefore, this study had as the main objective the Polystyrene (PS) toughening using different contents of white vulcanized styrene-butadiene rubber (SBRr) waste produced in the shoe industry. The mixtures were initially prepared in a co-rotational double screw extruder and, thereafter, the extruded granules were injection molded. Analyzed were the rheological, mechanical, thermomechanical properties and morphology of the produced blends. The rheological results showed a viscosity increase as the SBRr concentration was augmented, leading to a higher stability when compared to pure Polystyrene. Verified was an increase of impact resistance of 189% to the blend that contained 50% of SBR rather than pure Polystyrene. On the other hand, the traction properties, hardness Shore D, thermal deflection temperature (HDT) and Vicat softening temperature of the blends tended to decrease when compared to pure Polystyrene results. However, as this SBR waste is made up of a complex mixture of SBR, filler, processing additions, curing agents and stabilizers, it probably acted in the sense of not causing such a drastic reduction of the properties, even using a high concentration of SBRr waste. The morphologies obtained with the SEM method (Scanning Electronic Microscope) were quite different and typical of immiscible blends. The results show that it is possible to obtain a new material with good properties, valuing a discarded industrial waste and avoiding environment aggression.