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1

The impact of filler thermomechanical modifications on static and dynamic mechanical performance of flexible foamed polyurethane/ground tire rubber/zinc borate composites

Hejna Aleksander, Kosmela Paulina, Olszewski Adam, Formela Krzysztof, Zedler Łukasz, Piasecki Adam, Skórczewska Katarzyna

Composites Theory and Practice

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2023

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R. 23, nr 2

76--83

EN

The rapid development of the automotive industry is very beneficial to many aspects of human life, but it is also a very significant environmental burden. The most straightforward impact is related to the generation of exhaust, but the management of post-consumer car parts is also a major challenge. Among them, waste tires are very burdensome due to their enormous numbers. Therefore, it is essential to develop novel, environmentally friendly methods for their disposal, which would reduce their environmental impacts. One of the most promising approaches is shredding, resulting in the generation of ground tire rubber (GTR), which can be introduced into polymeric materials as a filler. The presented work is related to the thermomechanical treatment of GTR in a twin-screw extruder assisted by zinc borate (ZB), whose incorporation is aimed to increase interparticle friction within the extruder barrel. The impact of the treatment conditions on the particle size and Surface development of the GTR/ZB compositions was evaluated. Modified GTR was introduced into flexible polyurethane (PU) foams, and the impact on the static and dynamic mechanical performance of the resulting composites was investigated. Increasing the treatment temperature occurred to have an adverse effect on the tensile performance of the composites due to the agglomeration of GTR particles limiting the efficiency of stress transfer, which was also confirmed by dynamic mechanical analysis. On the other hand, increasing the ZB share in the GTR/ZB compositions limited PU disruptions related to the reactivity of the GTR functional groups with isocyanates, which enhanced the mechanical performance of the composites. It was proven that the proposed method of GTR thermomechanical treatment assisted by ZB might benefit the performance of flexible PU foamed composites, which could broaden the application range of GTR and provide novel ways for its efficient utilization.

2

Investigations of Flame Retardant Properties of Zinc Borate Accompanying with Huntite and Hydromagnesite in Polymer Composites

Atay Hüsnügül Yilmaz, Icin Öykü, Kuru Buket

Inżynieria Mineralna

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2020

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no. 1, vol. 1

79--86

EN

Fires have been a danger to human beings for the centuries. As people lost their lives and property in fires, they tried to fight the fire and their efforts in this area continued increasingly. Unfortunately, it is still not possible to completely reset the risk of starting the fire. But it seems likely to extinguish immediately after the fire has started, and this is very important to save people’s lives. Scientists have been working in this field in recent years; they are concentrated on producing fire-resistant materials using different materials. This can be provided by different ways; either fire-resistant material can be produced new, or the fire resistivity can be provided by incorporating the additive material into a flammable material. In our previous studies, we used huntite and hydromagnesite minerals to give fire resistance property to polymer materials, very successful results were obtained. In this study, huntite and hydromagnesite minerals were used for accompanying with zinc borate in polypropylene composites in order to increase the flame retardant property of a polymeric materials. Different content of minerals were blended with polypropylene, and composites were produced by twin-screw extruder for observing synergistic effect. Scanning electron microscopy (SEM) analyses were conducted to determine the structural and morphological properties of the composites. Thermal properties were determined according to thermogravimetric analysis (TGA). Tensile and three point bending tests were carried out to obtain mechanical properties. Flame retardant performance was evaluated according to UL 94 vertically flammability test. It was concluded that very good synergistic effects were obtained that zinc borate was significantly influential with huntite/hydromagnesite in the flammability characteristics of composites because higher char formation is observed with zinc borate addtion. Moreover, the zinc borate reduced the smoke generated during combustion.

PL

Pożary od wieków stanowią zagrożenie dla ludzi. Gdy ludzie stracili życie i mienie w wyniku pożarów, próbowali zwalczyć pożar, a ich wysiłki w tej dziedzinie były coraz bardziej skuteczne Niestety, nadal nie jest możliwe całkowite wyeliminowanie ryzyka rozpoczęcia pożaru. Ważne jest ugaszenie pożaru natychmiast po wybuchu aby uratować ludzkie życie. Naukowcy pracują w tej dziedzinie w ostatnich latach; koncentrują się na wytwarzaniu materiałów ognioodpornych przy użyciu różnych surowców. Można to zapewnić na różne sposoby; albo materiał ognioodporny może być wytworzony jako nowy, albo ognioodporność może być zapewniona przez włączenie materiału dodatkowego do materiału łatwopalnego. W badaniach używano minerałów huntite i hydromagnesitu, aby nadać materiałom polimerowym właściwości ognioodpornych, osiągając bardzo udane wyniki. W artykule przedstawiono wyniki wykorzystania minerałów huntitu i hydromagnezytu w obecności boranu cynku w kompozytach polipropylenowych w celu zwiększenia właściwości ognioodpornych materiałów polimerowych. Różne ilości minerałów zmieszano z polipropylenem, a kompozyty wytworzono za pomocą wytłaczarki dwuślimakowej w celu zaobserwowania efektu synergicznego. Przeprowadzono analizy skaningowej mikroskopii elektronowej (SEM) w celu określenia właściwości strukturalnych i morfologicznych kompozytów. Właściwości termiczne określono za pomoca analizą termograwimetryczną (TGA). Przeprowadzono próby rozciągania i zginania trzypunktowego w celu określenia właściwości mechanicznych. Działanie zmniejszające palność oceniono zgodnie z testem palności w pionie UL 94. Stwierdzono, że uzyskano bardzo dobre efekty synergiczne, boran cynku miał znaczący wpływ na huntit i hydromagnezyt i zmianę charakterystyki palności kompozytów, ponieważ obserwuje się podwyśzone powstawanie węgla drzewnego przy dodawaniu boranu cynku. Ponadto boran cynku zmniejszył ilość dymu powstający podczas spalania

3

Dissolution kinetics of smithsonite in boric acid solutions

Abali Y., Bayca S. U., Gumus R.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 1

161--172

EN

The dissolution of smithsonite in boric acid solutions was investigated. The influence of the reaction temperature, acid concentration, solid-to-liquid ratio, particle size and stirring speed on the zinc extraction were determined in the experiments. The results show that the dissolution rate increases with increasing acid concentration and reaction temperature, and with decreasing particle size and solid-to-liquid ratio. The dissolution results were analyzed by reaction control models. The activation energy of smithsonite in boric acid solution was also calculated.

4

The influence of a treatment process on the reaction to water of durable and water resistant wood/plastic composites

Hosseinihashemi S. K., Badritala A.

Drewno : prace naukowe, doniesienia, komunikaty

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2017

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vol. 60, nr 200

21--34

EN

In this study, the effect of the treatment process on the decay resistance and water absorption behaviour of wood flour/polypropylene composites was investigated. Composites based on ZB-pretreated, ZB-treated-during-manufacturing, and untreated wood flour, polypropylene were exposed to the decay by the white-rot fungus (Trametes versicolor) for 14 weeks. The long-term water absorptions of samples were evaluated by immersing them in water at room temperature for several weeks, and water diffusion coefficients (WDC) were also calculated by evaluating the water absorption isotherms. The morphology of the composites was characterized using scanning electron microscopy (SEM). The results showed that the composite made with ZB-treated wood flour exhibited the same water absorption as the control composite; while the ZB-pretreated wood flour, produced the highest improvements in water absorption performance. The water absorption of WPCs increased after exposure to white- rot fungus, where the water absorption of the decayed UT-WPC, ZB-T-WPC, and ZB-PT-WPC specimens increased by 41.4%, 43.25%, and 36.7%, respectively compared to the undecayed UT-WPC, ZB-T-WPC, and ZB-PT-WPC specimens. The undecayed ZB- -treated sample and decayed ZB-pretreated composite exhibited the lowest and highest WDCs, respectively. The SEM micrographs revealed that the outer surface of the wood fibers were coated by some crystalline deposits of zinc borate. Much larger WDC values are observed from the ZB-pretreated and decayed composites when compared to the ZB-treated, control, and undecayed composites. The results of this study help to clarify the effect of T. versicolor on the dynamic moisture absorption process of WPCs impregnated with ZB.

5

Zinc borate production with boron mineral source: effect of process parameters on yield and hydrophobicity

Acarali N. B., Ozturk E., Bardakcı M., Piskin M. B., Tugrul N.

Gospodarka Surowcami Mineralnymi

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2015

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T. 31, z. 4

95--109

EN

The aim of this study was to synthesize zinc borate by using zinc carbonate, boric acid, reference zinc borate (reference ZB) as seed and to investigate effects of modifying agents and reaction parameters on hydrophobicity and yield, respectively. Different from the studies available in the literature, the effects of different modifying agents (propylene glycol (PG) (0–6%), kerosene (1–6%), oleic acid (OA) (1–6%)) with solvents (isopropyl alcohol (IPA), ethanol, methanol) added to reaction on hydrophobicity were investigated comparingly. Firstly, the effects of reaction parameters such as reaction time (1–5 h), reactant ratio (H3BO3/ZnO) (2–5), seed ratio (0–1.5%, in terms of boric acid, w/w), reaction temperature (323–393 K), cooling temperature (283–353 K) and stirring rate (400–700 rpm) on yield were investigated. Furthermore, reactions were carried out under determined reaction conditions in both magnetically and mechanically stirred systems. The product, zinc borate, was characterized by analytical methods, XRD (X-ray Diffraction), FT-IR (Fourier Transform Infrared Spectroscopy) techniques and measurement of contact angle which identified hydrophobicity was carried out. In conclusion, it was observed that zinc borate was synthesized successfully and different modifying agents with various solvents affected the hydrophobicity of zinc borate.

PL

Celem tego artykułu jest synteza boranu cynku przy użyciu węglanu cynku, kwasu borowego, referencyjnego boranu cynku (ZB) jako substancji aktywnej oraz badanie efektywności tego procesu modyfikowanego odczynnikami i parametrami reakcji na hydrofobowość i wydajność syntezy boranu cynku. Dotyczy to działania różnych czynników modyfikujących hydrofobowość i parametry reakcji: glikol propylenowy (PG) (0−6%, kerozyna 1−6%, kwas oleinowy (OA) 1−6% oraz rozpuszczalniki: alkohol izopropylowy (IPA), etanol i metanol. Po pierwsze, badano jak wpływają następujące parametry reakcji na uzysk boranu cynku: czas reakcji (1−5 h), wskaźnik reaktywacji (H3BO3 : ZnO), (2−5), udział zarodków krystalizacji (0−1,5%) w odniesieniu do kwasu borowego, temperatura reakcji (50−120°C), temperatura chłodzenia (10−80 °C), szybkość mieszania (400−700 obr./min). Ponadto, reakcje były przeprowadzone w określonych warunkach mieszania mechanicznego i magnetycznego. Wytwarzany boran cynku ze względu na hydrofobowość badano metodami: dyfrakcji rentgenowskiej XRD, spektroskopii FT-IR oraz pomiarami kąta zwilżania. Reasumując, stwierdzono, że boran cynku można otrzymać z powodzeniem z różnymi rozpuszczalnikami wpływającymi na jego hydrofobowość.