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Thermal curves (a) peroxide vulcanizate, N, (b) peroxide vulcanizate containing 8 phr. Nanofil 2, N8N2, (c) sulphur vulcanizate containing 8 phr. Nanofil 2, S8N2
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This article presents the effect of the method of NBR cross linking on the thermal properties, flammability and fire hazard
of its nanocomposites containing modified montmorillonite (NanoBent or Nanofil), using test results obtained by means of a
derivatograph, oxygen index and cone calorimetry. It has been found that the thermal stability and fla...
Citations
... The residue after combustion is 22.25% (Fig. 5). 37 A sample of the allyl alcohol oligomer undergoes a singlestage thermal decomposition in the range of 60-245°C. The rate of thermal decay is 6.8% min −1 , while the residue after decomposition is 21.8%, at T = 600°C (Fig. S14 †). ...
There are few literature reports on using precatalysts based on ruthenium(II/III) ions in the polymerization of olefins. Therefore, a new coordination compound was designed based on ruthenium(III) ion and 2-phenylpyridine....
... As a result, reinforcing fillers like fumed and precipitated silica are commonly used to reinforce mechanical goods, which is fantastic for rubber [9][10][11][12]. The technological qualities improve when inorganic fillers are replaced with organic ones [13,14]. Polymers' physical properties are continuously altered by the adding filler, which also lowers the cost of device. ...
Abstract
Dielectric polymer composites have unusual properties that have significantly increased in a wide variety of applications. However, shape memory materials, which are a significant part of the category of smart materials, are substances that possess specific characteristics, namely, shape memory affect (SME) and pseudo -elasticity. SME has been examined using thermo-mechanical techniques. In this approach, silicone rubber (SiR) composites using Cu-Al-Zn alloy as fillers may be able to achieve a high permittivity and low dielectric loss. The purpose of this study is to explore the effect of Cu-Al-Zn alloy in particle form on the physical properties of silicone rubber. The results disclosed an improvement in stiffness and elasticity as well as dielectric properties of silicone rubber/Cu-Al-Zn alloy composites. The results showed lower hysteresis at higher Cu-Al-Zn alloy content. Further, the values of permittivity ε' and dielectric loss ε″ of the investigated composite were in case of using Cu-Al-Zn alloy. Besides, the SiR composites containing Cu-Al-Zn alloy have a promising insulating performance and can be used in electric insulation applications. Additionally, the values of conductivity of the SiR/ Cu-Al-Zn alloy composites vary from 10-13 to ~10-9 S cm–1. This value is sufficient for these composites to exhibit electrostatic dissipation behaviour.
Keywords:Silicone rubber (SiR); Cu-Al-Zn based alloy; rheology; physico-mechanical; dielectric properties; DSC;
... Among the nanofllers, layered silicates have been a popular topic of study among scientists and businesses. Intercalation of organically modifed layered silicates, for example, has a considerable impact on the thermal stability of acrylonitrile butadiene nanocomposites [1]. Te thermal stability of elastomeric nanocomposites with carbonaceous nanofller, which includes various kinds of graphene and carbon nanotubes [2][3][4][5][6][7], has been studied in the literature in recent years. ...
In this study, we show that adding halloysite nanotubes (HNT) to carbon black (CB)-packed acrylic rubber (ACM) composites improves their thermal properties. The thermo-oxidative stability, thermal stability, and dynamic mechanical properties of ACM composites (filled simply with 70 phr CB) and ACM hybrid composites comprising a fixed amount of CB (60 phr) and a variable amount of halloysite nanotubes (HNT) (2, 4, 6, 8, and 10 phr) were investigated. As evidenced by the oxidation induction time analysis, hybrid structures support a higher degree of antioxidation in composites reinforced with twin fillers than composites reinforced just with CB. ACM composites with dual fillers had greater breakdown temperatures (temperatures at 10% weight loss (T10) and 50% weight loss (T50)) and char residue concentration at 600°C than ACM conventional composites, according to thermogravimetric tests. The activation energy of the thermal disintegration of ACM composites, as determined by the Kissinger and Flynn–Wall–Ozawa techniques, shows that the addition of HNT improves the thermal stability of ACM composites. The storage modulus of ACM composites was increased by 79 percent at 30°C when 10 phr of black filler was replaced with 6 phr of tubular HNT, according to additional viscoelastic experiments.
... Good barrier abilities of NR_AM vulcanizates may occur due to the fibrous structure of filler and its high dispersion in the polymer matrix. Thin and flat yarrow particles may create a so-called "labyrinth effect" for penetrating gas in rubber composite likewise aluminosilicates [102]. Moreover, it can be related to the increased cross-linking density of these composites. ...
In this study, peppermint (Mentha piperita L.), German chamomile (Matricaria chamomilla L.) and yarrow (Achillea millefolium L.) were applied as natural fibrous fillers to create biocomposites containing substances of plant origin. The purpose of the work was to investigate the activity and effectiveness of selected plants as a material for the modification of natural rubber composites. This research was the first approach to examine the usefulness of peppermint, German chamomile and yarrow in the field of polymer technology. Dried and ground plant particles were subjected to Fourier transmission infrared spectroscopy (FTIR) and UV–Vis spectroscopy, thermogravimetric analysis (TGA), goniometric measurements (contact angle) and scanning electron microscopy (SEM). The characterization of natural rubber composites filled with bio-additives was performed including rheometric measurements, FTIR, TGA, cross-linking density, mechanical properties and colour change after simulated aging processes. Composites filled with natural fillers showed improved barrier properties and mechanical strength. Moreover, an increase in the cross-linking density of the materials before and after the simulated aging processes, compared to the reference sample, was observed.
... The plate structure of the ground roots and branches could improve the barrier properties. Thin layers of this type of fillers can act like aluminosilicates, creating a "maze" for penetrating gas [63]. ...
Common nettle (Urtíca Dióica L.), as a natural fibrous filler, may be part of the global trend of producing biocomposites with the addition of substances of plant origin. The aim of the work was to investigate and explain the effectiveness of common nettle as a source of active functional compounds for the modification of elastomer composites based on natural rubber. The conducted studies constitute a scientific novelty in the field of polymer technology, as there is no research on the physico-chemical characteristics of nettle bio-components and vulcanizates filled with them. Separation and mechanical modification of seeds, leaves, branches and roots of dried nettle were carried out. Characterization of the ground plant particles was performed using goniometric measurements (contact angle), Fourier transmission infrared spectroscopy (FTIR), themogravimetric analysis (TGA) and scanning electron microscopy (SEM). The obtained natural rubber composites with different bio-filler content were also tested in terms of rheological, static and dynamic mechanical properties, cross-linking density, color change and resistance to simulated aging processes. Composites with the addition of a filler obtained from nettle roots and stems showed the highest mechanical strength. For the sample containing leaves and branches, an increase in resistance to simulated ultraviolet and thermo-oxidative aging processes was observed. This phenomenon can be attributed to the activity of ingredients with high antioxidant potential contained in the plant.
... The antipyretic effect of the S: MMT filler resulted, inter alia, from the tubular effect well described in the literature. The montmorillonite plates dispersed in the NR rubber matrix enable the diffusion of gaseous waste products into the flame only through strictly defined channels, at the same time constituting a barrier to oxygen diffusion inside the composite [52,53]. ...
Increasingly, raw materials of natural origin are used as fillers in polymer composites. Such biocomposites have satisfactory properties. To ensure above-average functional properties, modifications of biofillers with other materials are also used. The presented research work aimed to produce and characterize elastomeric materials with a straw-based filler and four different types of montmorillonite. The main research goal was to obtain improved functional parameters of vulcanizates based on natural rubber. A series of composites filled with straw and certain types of modified and unmodified nano-clays in various ratios and amounts were prepared. Then, they were subjected to a series of tests to assess the impact of the hybrids used on the final product. It has been shown that the addition of optimal amounts of biofillers can, inter alia, increase the tensile strength of the composite, improve damping properties, extend the burning time of the material and affect the course of vulcanization or cross-linking density.
... Among the nanofllers, layered silicates have been a popular topic of study among scientists and businesses. Intercalation of organically modifed layered silicates, for example, has a considerable impact on the thermal stability of acrylonitrile butadiene nanocomposites [1]. Te thermal stability of elastomeric nanocomposites with carbonaceous nanofller, which includes various kinds of graphene and carbon nanotubes [2][3][4][5][6][7], has been studied in the literature in recent years. ...
In the present research, acrylic rubber (ACM) composites containing Carbon black (CB) of 70 phr alone and five different ACM hybrid nanocomposites containing a fixed content of CB (60 phr) and varied content of halloysite nanotubes (HNT) (2, 4, 6, 8 and 10 phr) were prepared by melt-blending on a open twin roll mill. The prepared composites were examined for their microstructure, physical and mechanical properties, hot air and hot oil ageing resistance. Studies revealed that addition of HNT in CB filled ACM composites resulted in superior mechanical properties, improved swelling resistance and augmented impedance to oxidation and hot oil compared to ACM containing CB alone. Further ACM composites with 6 phr of HNT demonstrated an enhancement of 31.49%, 16.15%, 39.65%, 6.39% and 28.06% respectively in stress at break, % elongation at rupture, modulus at 100% elongation, resistance to crack propagation and solvent uptake. Further the same sample exhibited retention of stress at break and elongation at rupture of 99% and 92%, 98% and 89%, 94% and 96% respectively in hot air, in IRM 901 oil and in IRM 903 oil respectively. Studies on the microstructure revealed the formation of HNT-ACM-CB intercalated structures. Fourier transform infrared spectroscopy studies confirmed the establishment of bonding of hydrogen amidst the tubular nanofiller and the ACM rubber. Field emission scanning electron microscopy studies divulged the intercalation of tubular filler by ACM rubber, black filler and curing constituents and development of local HNT-CB network. These studies prove that partial replacement of traditional CB filler with tubular HNT is a promising approach to produce ACM composites with superior mechanical, thermo-oxidative ageing and hot oil ageing properties.[Formula: see text]
... At that time, the resistance against cracking of the ozone layer increases and, consequently, prolonged life-time effectiveness, which is also confirmed by thermal phenomena [differential thermal analysis (DTA), thermogravimetry (TG)] occurring at high temperatures for the intercalated compound. In other studies [27] it was observed that the thermal stability and flammability of the tested nanocomposites depend both on the structure of the rubber network and the type of montmorillonite. Nanoadditives (aluminosilicates) are used to reduce the flammability of cross-linked NBR butadiene nitrile rubber and significantly reduce its fire hazard. ...
... The tests were carried out with constant nitrogen flow rate of 400 L h −1 , the oxygen flow was selected so that the sample tested was totally burned, including flame decay, within t = 180 s. The sample top was ignited for 15 s by means of a gas burner using a propane-butane mixture [27]. ...
The presented study includes a comparison of the effect of fillers used in carboxylated nitrile butadiene rubber XNBR on the properties of the obtained polymer materials. Fillers used in this study originated from the tanning industry waste: cattle hair keratin, enzymatic hydrolyzate of cattle hair keratin and condensate of enzymatic hydrolyzate of cattle hair keratin. The use of commonly found in nature phyllosilicates allows to obtain nanocomposites. That is why in the presented study we used different mass fraction of layered silicate—montmorillonite. The dispersion of silicates in polymer matrices can be influenced by their physical and chemical modifications that lead to changes in the properties of the polymer matrices themselves. In the presented study the kinetics of vulcanization of elastomer blends was investigated, and the obtained XNBR rubber vulcanizates were analyzed for mechanical, optical, rheological, thermal analysis and their resistance to accelerated thermo-oxidative aging (S) and susceptibility to biodegrade were tested. The produced elastomer composites may be used in the rubber industry in the assortment of various types of washers, elastomer seals or conveyor belts—materials that often work under elevated temperature conditions. Therefore, it seems advisable to understand the thermal properties of this type of materials, eg for suitability in real conditions. Therefore, Thermogravimetry (TG), Differential Scanning Calorimetry (DSC), Oxygen Index (IO) analyzes have been carried out, showing that different mechanisms of decomposition occur in layers of fiber-enriched polymer composites than unrecoverable ones. The modified keratin also slightly decreases the glass transition temperature. In addition, the presence of a modified keratin in the XNBR elastomer structure increases the composites compliance with the biodegradation process.
... Organocally modified silicates are highly effective in retarding the combustion of polymeric materials due to their layered structures. Very recently, the effect of modified MMT on the FR characteristics of NBR with a 22% AN content was investigated [229]. The vulcanazites were prepared in the presence of sulfur and peroxide. ...
... The OI values with sulfur vulcanazites have also been reported, which indicated that both the grades of fillers can improve the OI values. They reduce the flammability through the labyrinth effect: the volatile products are trapped in the layers of MMTs, and thus, further combustion of inner layers of polymer is restricted [229]. ...
This article presents a comprehensive review about previous research done for the development of elastomeric nanocomposites (NCs) based flame retardant (FR) materials. Conservatively, a single fire retardant element can achieve fire retardancy, but we report about combinations of elastomers and various fire retardant materials at nanoscale, including layered materials and inorganic materials for the development of polymeric and elastomeric NC based FR materials. We have critically reviewed and summarized the surface morphological structure, organic treatment for surface modification, dispersion phenomenon, fire retardant action and the flame-retarding properties of various elastomeric NCs. We also highlight the fundamentals and combustion mechanism of fire retardancy tests, which have been used to describe fire behavior, nature and modes of FR materials and their synergistic effects. We have focused particularly on elastomeric NCs filled with specific, finely dispersed different nanofillers, which will undoubtedly pave the way for development of FR materials showing physico-mechanical and enhanced FR performance. This review article will objectively explore and give new direction for the development of the “FR materials” which would be more accessible to the emerging field of materials science.
... The general improvement in flammability tests of the elastomeric composites filled with phthalocyanine pigments is due to the impediment of heat and mass exhange between solid and gaseous phase caused by carbonization processes in the boundary layer, resulting in creating a char residue, which works as a barrier. The yield of carbonization processes is mainly dependent on the chemical structure of rubbers used (35)(36)(37). Those processes are more efficient in polar rubbers, so NBR-based composites are more thermally stable and they are less flammable than SBR-based ones. ...
A study about the influence of the impartment of phthalocyanine pigments into elastomeric composites was conducted. Acrylonitrile-butadiene (NBR) and styrene-butadiene (SBR) rubbers crosslinked by either sulfur or dicumyl peroxide were filled with non-toxic flame retardants (Mg(OH)2 or Al(OH)3) and thermally stable pigments (zinc or chloroaluminum phthalocyanines). Determination of cross-linking degree, mechanical properties, aging coefficient, thermal analysis (TG, DTG, DTA) and flammability tests (oxygen index, combustion in air) were carried out. The addition of the pigments, apart from the impartment of blue or blue-green color to elastomeric composites, in numerous cases improved their mechanical properties, thermal stability, limited flammability and allowed obtaining self-extinguishing materials in atmospheric air.
