Search

Highlights The strategic alignment of nanoplatelets within polymer matrices is pivotal for the development of nanocomposites with superior gas barrier characteristics. In this work, the effect of lamellar particles orientation in polymer for gas permeation was demonstrated. The magnetic α‐Al2O3 (Al2O3@PDA‐Fe3O4) was first prepared by in situ growth of Fe3O4 nanoparticles immobilized on polydopamine (PDA)‐modified Al2O3 surface. Subsequently the orientation of magnetic α‐Al2O3 in brominated butyl rubber (BIIR) was achieved by modulating the applied magnetic field direction. Results show that the PDA, as the role of surface adhesive, not only anchored Al2O3 substrate but also bound ferric ions for the further in situ formation of Fe3O4, which ensured the physico‐chemical stability of the magnetic α‐Al2O3. Comparison of hydrogen permeation performance of composites with in‐plan, middle‐of plane and out‐of plane alignment demonstrated the effect of lamellar particles orientation. The Al2O3@PDA‐Fe3O4/BIIR composite with in‐plane alignment had the best hydrogen barrier property by a 50% reduction in hydrogen permeability coefficient compared to the neat BIIR, underscoring the critical role of particle orientation in enhancing the gas barrier properties of nanocomposites. The structural stability of magnetic Al2O3 nanocomposites was enhanced by polydopamine (PDA). The composites with in‐plane alignment, middle‐of plane alignment and out‐of plane alignment were prepared by a magnetic field. The effect of lamellar particles orientation on gas permeation of polymer nanocomposites was studied. The composites with in‐plane alignment possesses the best gas barrier property. [ABSTRACT FROM AUTHOR]

This study investigates the impact of aging in methyl diethanolamine (MDEA) solution on cured rubber compounds comprising ethylene‐propylene‐diene monomer rubber (EPDM), butyl rubber (IIR), and blends, utilizing nano (nZnO) and conventional (ZnO) zinc oxides as curing activators. The analysis reveals that MDEA solution induces degradation in the rubber matrix by grafting amine and amide groups onto the rubber backbone, particularly affecting unsaturated units in diene monomers in EPDM and isoprene units in IIR. The Fourier‐transform infrared (FTIR) analysis validated the addition of these functional groups. Aging contributed to the formation of a thin rubber layer covering carbon black particles, likely due to un‐crosslinking and rubber chain scission, resulting in changes in bound rubber as observed in scanning electron microscopy (SEM) images. Tensile strength and elongation at break typically decreased with aging, with EPDM compounds exhibiting the highest initial tensile strength and IIR compounds demonstrating superior initial elongation. Hardness remains largely unaffected by aging. This study showed the detrimental effects of MDEA exposure on rubber compounds, emphasizing the critical importance of material selection and property tailoring for specific applications in MDEA‐rich environments, such as gas refineries. [ABSTRACT FROM AUTHOR]

This study aims to investigate the toughening effects of rubber and thermoplastic particles on epoxy resin (EP), and to understand the mechanism underlying their synergistic effect. For this purpose, three EP systems were prepared using diglycidyl ether of bisphenol-A (DGEBA) epoxy resin (E-54) and 4,4-Diamino diphenyl methane (Ag-80) as matrix resin, 4,4-diaminodiphenyl sulfone (DDS) as a curing agent, and phenolphthalein poly (aryl ether ketone) particles (PEK-C) and carboxyl-terminated butyl liquid rubber (CTBN) as toughening agents. These systems are classified as an EP/PEK-C toughening system, EP/CTBN toughening system, and EP/PEK-C/CTBN synergistic toughening system. The curing behavior, thermal properties, mechanical properties, and phase structure of the synergistic-toughened EP systems were comprehensively investigated. The results showed that PEK-C did not react with EP, while CTBN reacted with EP to form a flexible block polymer. The impact toughness of EP toughened by PEK-C/CTBN was improved obviously without significantly increasing viscosity or decreasing thermal stability, flexural strength, and modulus, and the synergistic toughening effect was significantly higher than that of the single toughening system. The notable improvement in toughness is believed to be due to the synergistic energy dissipation effect of PEK-C/CTBN. [ABSTRACT FROM AUTHOR]

Stoma surgery can be critical in helping to restore the well-being of patients suffering from gastrointestinal disease or injury but it inevitably comes with numerous psychological and physiological complications. Disposable pouch systems which enable the collection of bowel waste have revolutionized stoma care but providing robust, discreet devices that can efficiently meet the requirements of the patient can be challenging. Pouches must securely store a microbially active waste whilst preventing leakage, protecting the underlying skin from inflammation and minimizing odor. All of this needs to be achieved within the design constraints of a pouch that is easy to manage and yet still maintains a discreet body contour. Stoma collection has moved from the waste being collected in butyl rubber pouches to much more elaborate systems incorporating assemblies of polyvinylidene chloride, ethylene vinyl acetate, ethyl vinyl alcohol and polyvinyl alcohol with new, skin-friendly adhesive such as hydrocolloid and silicones impregnated with ceramides and aloe. Moreover, 3D printing has emerged as a means of providing personalized stoma pouches that can potentially address the age-old issue of leakage. Despite such advances, stoma pouches have evolved slowly over the past 70 or so years. A survey of the literature reveals an abundance of quality-of-life studies but a dearth of reports addressing the key technological challenges. Consequently, this narrative review considers current stoma pouch technology and highlights the issues that continue to afflict stoma patients. Research and patent literature is critically appraised in terms of current pouch technology and the potential opportunities for new composite materials are identified. [ABSTRACT FROM AUTHOR]

In this paper, we enhance the adhesion strength of butyl rubber-based vibrational damping plates using nanoscale self-assembled monolayers of various silane coupling agents. The silane coupling agents used to chemically modify the plate's aluminum surface include 3-aminopropyltriethoxysilane (APTES), (3-glycidyloxypropyl) triethoxysilane (GPTES), 3-mercaptopropyltrimethoxysilane (MPTMS), and 3-(triethoxysilyl)propyl isocyanate (ICPTES). The modified surfaces were analyzed using Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the enhancement in adhesion strength between the rubber and aluminum was estimated through T-Peel tests. As a result, MPTMS showed the highest enhancement in adhesion strength, of approximately 220% compared to the untreated sample, while GPTES, ICPTES, and APTES resulted in adhesion strength enhancements of approximately 200%, 150%, and 130%, respectively. [ABSTRACT FROM AUTHOR]

Zinc oxide/melamine hypophosphate (MHS)/butyl tape premix (BTP) flame-retardant composites were prepared by mixing MHS, zinc oxide and BTP using mechanical blending method and the synergistic flame retardant effect between zinc oxide and MHS was investigated. The combustion performance and thermal stability of zinc oxide/MHS/BTP composites were studied by scanning electron microscope, limited oxygen index, cone calorimetry and thermogravimetric analysis, and the effect of zinc oxide on the adhesive performance of zinc oxide/MHS/BTP composites was studied by persistent adhesion and peel strength test. The results showed that the addition of zinc oxide could adjust the carbon formation and foaming process of the MHS/BTP composite and result in the generation of a complete gas chamber structure. The limited oxygen index of the composite increased from 28.5% to 33.0%, the vertical combustion grade of UL-94 increased from V-1 to V-0, the peak of heat release rate of the MHS/BTP flame-retardant composite could decrease by 66.7% at most, the total heat release decreased by 22.0%, the peak of smoke release rate decreased by 67.3% and the total smoke release decreased by 58.5%. The mass fraction of carbon residue of the MHS/BTP flame retardant composite increased from 25.58% to 40.41% and the maximum thermal decomposition temperature increased from 344.96 °C to 394.91 °C. The addition of zinc oxide would lead to a slight reduction of persistent adhesion and peel strength of the MHS/BTP flame retardant composite.

Thermomechanical devulcanization of butyl rubber (BR1), bromobutyl rubber (BR2) vulcanizates, both prepared in laboratory, and a waste commercial butyl rubber (BR3) using a twin-screw extruder is reported. The commercial butyl rubber vulcanizate (BR3) was used as a tire curing bladder and the waste rubber received from a tire manufacturing company. The devulcanization process was carried out at various barrel temperatures and screw speeds (40, 80 and 120 r/min). The lowest sol fraction was obtained for devulcanized waste commercial butyl rubber (D-BR3). According to Horikx theory, devulcanized butyl rubber (D-BR1) presented mainly crosslink breakup while devulcanized bromobutyl rubber (D-BR2) and devulcanized waste commercial butyl rubber (D-BR3) showed a mixture of main chain and crosslink scission. As cure rheographs at 190°C indicated, the addition of devulcanized rubbers to the corresponding virgin ones influenced both scorch and optimal cure times. The tensile properties of devulcanized/virgin rubber blends changed depending on the blend type and virgin rubber. The stress relaxation experiment revealed that the addition of devulcanized rubber to virgin one mostly influenced short relaxation times and also decreased G0. BR1/D-BR3 blends exhibited higher elastic component than BR1/D-BR1 and BR2/D-BR2 samples. The Han plots revealed higher compatibility for BR2/D-BR2 blends. [ABSTRACT FROM AUTHOR]

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents the results of an experimental modal analysis of a beam covered by polymer materials used as a passive vibration isolation. The main aim of this study was to determine the damping properties of selected viscoelastic materials. In order to check the damping properties of tested materials, an experimental modal analysis, with the use of an electrodynamic vibration system, was performed. In this study, four kinds of specimens were considered. In the first step of the work, the beam made out of aluminum alloy was investigated. Afterwards, a cantilever beam was covered with a layer of bitumen-based material acting as a damper. This method is commonly known as a free layer damping treatment (FLD). In order to increase the damping capabilities, the previous configuration was improved by fixing a thin aluminum layer directly to the viscoelastic core. Such a treatment is called constrained layer damping (CLD). Subsequently, another polymer (butyl rubber) in the CLD configuration was tested for its damping properties. As a result of the performed experimental modal analysis, the frequencies of resonant vibrations and their corresponding amplitudes were obtained. The experimental results were used to quantitatively evaluate the damping properties of tested materials. [ABSTRACT FROM AUTHOR]

The industry's mechanical equipment often faces a significant demand for damping rubber. Simultaneously improving damping and toughness of rubber materials is a challenging task. It was achieved by incorporating crystal particles into the chlorinated butyl rubber (CIIR) network, inspired by the "sliding crystal mechanism". To create the elastomers with high damping and toughness, polyurethane was used along with polyethylene glycol as a soft segment. The combination factors, including coordination and hydrogen bonds, played a crucial role in facilitating the formation of crystal particles within the material. These crystal particles acted as rigid fillers, enhancing the material's toughness. Additionally, the sacrificial reversible bonds present in the crystal particles allowed for energy dissipation during stress. These bonds can be repeatedly broken and regenerated, enabling the material to dissipate energy efficiently. Comparing these elastomers to pure CIIR, they exhibited a tensile strength and elongation at break of 5.76 MPa and 1973%, a fracture energy of 28.73 MJ/m3, a damping factor of 1.52, and a damping temperature range of 80 °C. These results indicate significant improvements in both damping and toughness properties. This advancement could have valuable implications for the industry's mechanical equipment, which often relies on effective damping rubber. [ABSTRACT FROM AUTHOR]

An experimental device fixed with a laser displacement sensor was assembled to investigate the rebound behaviors and damping mechanism of rubber balls prepared with ethylene-propylene-diene monomer (EPDM)/chlorinated butyl rubber (CIIR) blends. The result showed that a prediction model was proposed to characterize the damping capacity by using the rebound height of the rubber balls. The lower rebound height corresponded to better damping capacity. A modified equation relating to the rebound height has been obtained from the theoretical derivation on the basis of the dynamic mechanical analysis, showing that the rebound height was affected by the deformation frequency, the external excitation, and the nature of rubber blends. Furthermore, the energy dissipation rate (EDR), defined by the ratio of the height loss to the rebound time, was proposed to further characterize the damping capacity. The EDR value was shown to be highest for the pure CIIR and lowest for the pure EPDM, exhibiting a decreasing trend with the increase in EPDM content in the rubber blends. It can be expected that the damping capacity of the EPDM/CIIR blends decreases with the decrease in external excitation, the conclusion of which plays a key role in the formulation design of viscoelastic damping rubber materials. [ABSTRACT FROM AUTHOR]

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of the study was to produce new elastomeric materials containing butyl rubber (IIR) filled with silica and phyllosilicates (vermiculite, montmorillonite, perlite or halloysite tubes) with enhanced hydrophobicity and barrier properties and reduced chemical degradation. It was found that the filler type had a significant impact on the degree of cross-linking of butyl rubber and the properties of its vulcanizates. The highest degree of cross-linking and the highest mechanical strength were achieved for IIR composites filled with Arsil with perlite or halloysite tubes. The highest surface hydrophobicity (119°) was confirmed for the IIR vulcanizates with Arsil and montmorillonite. All tested samples showed high barrier properties because both the gas diffusion rate coefficient and the permeability coefficient reached low values. Both unfilled and filled IIR vulcanizates retained chemical resistance in contact with methanol for 480 min. Hour-long contact of a polar solvent (methanol) with each of the vulcanizates did not cause material degradation, while the presence of a non-polar solvent (n-heptane) worsened the mechanical parameters by up to 80%. However, the presence of fillers reduced the chemical degradation of vulcanizates (in the case of cured IIR filled with Arsil and halloysite tubes by 40% compared to the composite without fillers). [ABSTRACT FROM AUTHOR]

The high elasticity and excellent gas barrier properties of rubber composites make them irreplaceable in the field of sealing. Constructing a complicated barrier network to reduce free volume is crucial to improving gas barrier properties. In this research, liquid acrylonitrile-butadiene rubber/γ-Methacryloxypropyl trimethoxy silane (KH570) modified graphene oxide/butyl rubber composites (LNBR/KGO/IIR) were fabricated. A KGO lamellar network was constructed to resist gas diffusion in the IIR matrix. Meanwhile, LNBR macromolecules further occupied the free volume inside the IIR composites, thereby maximizing the retardation of the path of small molecule gas permeation. The modification of GO by KH570 was successfully demonstrated through FTIR and XRD. The grafting rate of KH570 was calculated to be approximately 71.4%. KGO was well dispersed in IIR due to emulsion compounding and the formation of lamellar networks. The 300% modulus, tensile strength and tear strength of KGO/IIR were improved by 43.5%, 39.1% and 14.8%, respectively, compared to those of the IIR composite. In addition, the introduction of LNBR resulted in a 44.2% improvement in the gas barrier performance of nitrogen permeability relative to the original IIR composite. [ABSTRACT FROM AUTHOR]

It is of interest to develop wide-temperature domain damped hydrophobic materials. In this paper, we designed incorporating bio-based phenolic resin into the IIR matrix and introducing dibenzyl fork acetone (DBA) into the main chain structure with sodium hydroxide activation to construct three-dimensional network. In this paper, we designed incorporating bio-based phenolic resin into the IIR matrix and introducing dibenzyl fork acetone (DBA) into the main chain structure with sodium hydroxide activation to construct three-dimensional network. The added bio-based phenolic resin has reticulated structure blended with butyl rubber, combined with sodium hydride activation-modified IIR. The results show that sodium hydride activated modification of DBA is introduced into the main chain structure of IIR by infrared and 1H NMR analysis. The material hydrophobic is realized by the introduction of DBA with static water contact angle of 103.5°. The addition of 10phr lignin-based phenolic resin (LPF) is compatible with IIR, and the torque can reach 7.0 N-m. The tensile elongation of the modified butyl rubber composite can reach 2400% with tensile strength up to 11.43 MPa, while the damping factor can reach 0.37 even at 70 °C. The thermal stability of the composites is enhanced with mass retention rate of 28%. The bio-based PF/NaH activation-modified butyl rubber damping material has potential applications in damping hydrophobicity with wide temperature range. [ABSTRACT FROM AUTHOR]

In the present study, the effect of elastomer ratios in solution-based mixtures on the formation of the phase structure and properties of compositions based on butyl rubber, chlorobutyl rubber, and ethylene-propylene-diene rubber was investigated. This work determined the influence of the elastomer ratios in uncured blends and their impact on the patterns of phase structure formation in multicomponent polymer systems, alterations in molecular mobility, and their influence on ozone resistance. Attenuated total reflectance – Fourier transform infrared spectroscopy was employed to analyze the chemical structure of the polymer surfaces. The influence of blend ratio (mass percentage ratios of 100/0, 80/20, 60/40, 50/50, 40/60, 20/80, and 0/100) on the phase structure and surface ozone oxidation was studied. The green strengths of the blends of ethylene-propylene-diene rubber and butyl/chlorobutyl rubbers were studied over a wide range of blend ratios. [ABSTRACT FROM AUTHOR]

This paper proposes a new low loss high dielectric substrate made of CaTiO3 incorporated butyl rubber (CBR). The synthesized material has a dielectric loss of 0.0048 and dielectric constant of 11.7. A novel circular anisotropic structure is used in the design of metamaterial unit cell. This metamaterial structure exhibits near-zero refractive index at 2.4 GHz. The extraction of refractive index is done from the scattering parameters using generalised sheet transition condition. An array of 3x3 unit cell is the metasurface superstrate, which is proposed for the gain enhancement. It is kept above the microstrip patch antenna working at 2.4 GHz. The proposed superstrate provides a gain enhancement of 4.6 dB. The height between the antenna and superstrate is optimized to 0.088 λ. The enhancement of gain on metasurface substrate with different loss tangents is analyzed. The simulation and measurement results of antenna with superstrate show good agreement with a peak gain of 7.6 dBi. The radiation efficiency of the antenna is increased by 42%. [ABSTRACT FROM AUTHOR]

In this paper, we enhance the adhesion strength of butyl rubber-based vibrational damping plates using nanoscale self-assembled monolayers of various silane coupling agents. The silane coupling agents used to chemically modify the plate’s aluminum surface include 3-aminopropyltriethoxysilane (APTES), (3-glycidyloxypropyl) triethoxysilane (GPTES), 3-mercaptopropyltrimethoxysilane (MPTMS), and 3-(triethoxysilyl)propyl isocyanate (ICPTES). The modified surfaces were analyzed using Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the enhancement in adhesion strength between the rubber and aluminum was estimated through T-Peel tests. As a result, MPTMS showed the highest enhancement in adhesion strength, of approximately 220% compared to the untreated sample, while GPTES, ICPTES, and APTES resulted in adhesion strength enhancements of approximately 200%, 150%, and 130%, respectively.

The cured rubber-made bladder used for curing the green tire because, it is thermally stable, and has low gas permeability. The bladder is made with the cured butyl rubber as a base rubber under a phenolic curing system. To save the resources and also, the environmental protection, it should be de-crosslink to gum rubber. A commercial source waste bladder rubber compounded with different de-crosslinking agents, including TMTD, DPDS, DCBS, MBTS, MBT, and TBBS. To do de-crosslinking, the prepared compounds were heated in a laboratory heating oven at different temperatures. The de-crosslinking parameters including the sol fraction and de-crosslinking percent measured using traditional rubber swollen tests. The Fourier transform infrared spectroscopy (FTIR) graphs showed the existence of the phenolic resin in the structure of waste bladder butyl rubber powder. Efficient de-crosslinking was observed for all studied de-crosslinking agents. It evidenced by the scanning electron microscope micrographs and also, the measured crosslink densities of the reclaimed rubbers. The highest and the lowest de-crosslinking percents belonged to the compounds with 4 phr DPDS in recipe at 220 ℃ and 4 phr DCBS at 180 ℃ , respectively. Based on the obtained de-crosslinking parameters, the DPDS was selected as a suitable de-crosslinking agent for used waste rubber. In accordance with Horikx analysis, the oven heating broke down the crosslinks and rubber main chains simultaneously. Increasing the oven temperature had a positive effect on de-crosslinking process with similar effects on the crosslink and main chain break down. Graphical Abstract [ABSTRACT FROM AUTHOR]

The development of a heat conductive formulation for rubber composites is essential for technical applications such as tire-curing bladders. The present study addresses the effects of three potential ceramic fillers, namely titanium carbide (TiC), silicon carbide (SiC), and alumina, on the mechanical and thermal properties of carbon black (CB)-filled butyl rubber composites. The composites were prepared using the melt compounding method. The curing, mechanical, and thermal conductivity properties of the composites were determined. The tensile strength and modulus of composites decreased slightly in the presence of ceramic fillers in lower amounts of filler loading (10 Phr). Further they reduced in a higher amount of filler loading (20 Phr). In addition, the thermal diffusivity coefficient of the composites increased in the presence of ceramic fillers with different values depending on the type and the amount of the filler with the rank of Al2O3 > SiC > TiC at 10 Phr of filler loading and SiC > TiC > Al2O3 at 20 Phr of filler loading. These different behaviors were discussed according to the state of filler dispersion in the rubber matrix and rubber–filler interactions according to the FeSEM visualization and the mechanical properties. [ABSTRACT FROM AUTHOR]

The damping performance of chlorinated butyl rubber (CIIR) cannot satisfy the rigorous requirements of damping and vibration reduction. Hindered phenol can endow rubber composites with good damping performance, but these small molecules may migrate from rubber matrices. Here, a novel type of damping agent based on the hyperbranched polyester grafted hindered phenol (AG-HP102) was prepared by grafting hindered phenol (AG) with hydroxyl terminated hyperbranched polyester (HP102). It was then incorporated into chlorinated butyl rubber (CIIR) to prepare damping rubber composites. The test results showed that tan δmax of CIIR/AG-HP102 (7 phr) was 1.40, which was 32.1% higher than that of pure CIIR, 1.05. In addition, the glass transition temperature (Tg) was increased from − 26.0 to − 16 ℃. The mechanical property tests showed that the tensile strength and elongation at break of the CIIR/AG-HP102 (7 phr) composite reached 8.21 MPa and 1192%, respectively, which was 290.9% and 39.5% higher than those of pure CIIR, 2.11 MPa and 858%. These experiment results can offer some useful information for the design and fabrication of high-performance polymeric damping materials. [ABSTRACT FROM AUTHOR]

Low‐loss Sr2Ti9O20 (STO)/butyl rubber (BR) composites have been prepared by mixing and hot pressing. X‐ray diffraction and energy‐dispersive spectroscopy are employed to investigate the phases contained in the STO filler, and the microstructural characteristics of the composites are discovered using scanning electron microscopy. The STO/BR composites demonstrate a high relative permittivity of 10.98 and a low loss of 0.003 at 10 GHz, corresponding to an optimum filler volume fraction of 45%. In addition, a low coefficient of thermal expansion of 50.72 ppm °C−1 and a high thermal conductivity of 0.9603 W m−1 K−1 have been found for the optimum composition, with an acceptable moisture absorption of 0.071%. The obtained composites can be employed for miniaturized, flexible radio‐frequency substrate applications. [ABSTRACT FROM AUTHOR]

Reclaimed rubber (RR) from butyl tubes was evaluated as a partial and full replacement of a virgin rubber which is carboxylated nitrile butadiene (XNBR). This study involves the blending of carboxylated nitrile butadiene rubber with butyl reclaimed rubber (XNBR/BRR) in various loadings and cured with sulfur by using a two-roll mill. The objective is to investigate the effect of RR loading on crosslink density and mechanical properties of XNBR/BRR blends. The mechanical properties such as hardness, rebound resilience, tear strength, tensile strength, elongation at break, and modulus were evaluated. In this study, the amount of reclaimed rubber varied from 0 phr to 161 phr. The results showed that the rebound resilience, tear strength, and tensile strength had a reduction of 43%, 27%, and 67%, respectively. Also, the hardness and modulus increased by 17% and 60% each. As for the elongation at break, it had a decrease of 69% and then an increment of about 77%. These results appeared due to the low molecular 1 weight of the BRR800 and the presence of processing oil and carbon black in the reclaimed rubber itself. This study could prove that reclaimed rubber can be fully utilized by putting it to good use in producing good quality rubber-based products. [ABSTRACT FROM AUTHOR]

One of the best elastomers for the inner liner of a tire is brominated butyl rubber (BIIR). On the other hand, cutting‐edge automobile technologies call for BIIR with enhanced curing, mechanical, and barrier qualities. Consequently, in this investigation, BIIR blends were created with different elastomers that have similar permeability qualities of BIIR but have improved physical properties. Elastomeric blends of BIIR with epoxidized natural rubber (ENR), hydrogenated nitrile rubber (HNBR), and polyepichlorohydrin rubber (CO) were prepared using a melt mixing procedure that could be scaled up for commercial use. The crosslinking behavior, physical, morphological, and barrier characteristics of the developed blends were assessed. The crosslinking properties of new blends revealed a 100% improvement in torque difference, indicating superior cocurability of them with other general‐purpose rubbers used in tire in comparison to the reference BIIR sample. It was also found that the newly developed blends have enhanced mechanical qualities without sacrificing the air impermeability of BIIR, which in turn gives the capacity to withstand high air pressures and thereby a decrease in rolling resistance. [ABSTRACT FROM AUTHOR]

Traditional butyl rubber halogenation technology involves the halogenation of IIR using molecular chlorine or bromine in a solution. However, this method is technologically complex. This study investigated a novel method for the halogenation of butyl rubber to enhance its stability and resistance to thermal oxidation and aggressive media. The butyl rubber was modified through mechanochemical modification, induced by solvent swelling in a polychlorinated n-alkane solution. During the modification, samples were obtained with chlorine content ranging from 3 to 15%. After extraction, the halogen content was quantitatively determined with the oxygen flask combustion method and X-ray photoelectron spectroscopy. It was shown that for samples with total chlorine content of up to 6%, there was almost no leaching of chlorine from the samples. The chemical structure of the extracted rubbers was ascertained using FT-IR and 1H NMR spectroscopy, and it was demonstrated that all samples showed absorption peaks and signals typical for chlorobutyl rubbers. It was observed that modification with polychlorinated n-alkanes improved the thermal and oxidative stability (the oxygen absorption rate decreased by 40%) and chemical resistance, estimated by the degree of swelling, which decreased with the increase in the chlorine content. This technology allows the production of a chlorinated rubber solution that can be directly used by rubber goods manufacturers and suppliers. [ABSTRACT FROM AUTHOR]

Ionic crosslinking of bromobutyl rubber (BIIR) composites was prepared using butylimidazole (IM) and ionic liquid (IL), combined with carbon nanotubes (CNT) and conductive carbon black (CCB) to enhance the intrinsic properties and heal ability of the resulting composites. Variation in the BIIR/CNT-CCB/IM/IL ratios was investigated to determine the appropriate formulation for healing the composites. Results showed that the mechanical properties were increased until the IM:IL:CNT/CCB ratio reached 1:1:1/1.5, corresponding to the optimal concentration of 5:5:5/7.5 phr. Thermo-oxidative degradation, as indicated using temperature scanning stress relaxation (TSSR), demonstrated the decomposition of the composites at higher temperatures, highlighting the superior resistance provided by the proper formulation of BIIR composites. Additionally, the conditions for the healing procedure were examined by applying pressure, temperature, and time. It was observed that the composites exhibited good elasticity at 0 °C and 60 °C, with a high rate of re-crosslinking achieved under appropriate pressure and temperature conditions. This research aims to develop a formulation suitable for the tire tread and inner liner of commercial car tires together with artificial skin products. [ABSTRACT FROM AUTHOR]

Brominated butyl rubber (BIIR) is a derivative of butyl rubber, with the advantage of high physical strength, good vibration damping performance, low permeability, aging resistance, weather resistance, etc. However, it is hard to avoid BIIR fiber sticking together due to serious swelling or merging, resulting in few studies on BIIR electrospinning. In this work, brominated butyl rubber membrane (mat) with BIIR microfiber has been prepared by electrospinning. The spinnability of elastomer BIIR has been explored. The factors influencing the morphology of BIIR microfiber membranes have been studied, including solvent, electrospinning parameters, concentration, and the rheological property of electrospinning solution. The optimal parameters for electrospinning BIIR have been obtained. A BIIR membrane with the ideal microfiber morphology has been obtained, which can be peeled from aluminum foil on a collector easily without being broken. Anti-bacterial property, the electrical conductivity of these membranes, and the mechanical properties of these samples were studied. The optimized BIIR electrospinning solution is Bingham fluid. The results of these experiments show that a BIIR membrane can be used in the field of medical prevention, wearable electronics, electronic skin, and in other fields that require antibacterial functional polymer materials. [ABSTRACT FROM AUTHOR]

Reinforced concrete infilled frames have been studied over the years along with the infilled openings. To resist the lateral loads that are applied on the frames, stress is transferred from the reinforced concrete (RC) to infill, which leads to brittle collapse. The conventional interface medium, which was considered by researchers and recent studies, was prepared by changing the interface materials between the RC frame and infill panels to different elastic materials. This study focuses on optimizing the interface pressure using a butyl rubber tube, which reduces the stress distribution to the infill panel from the RC frame. A 50% window opening was adopted in this study, which is the optimized size from previous research. The optimization patterns followed linear and nonlinear patterns, such as the same pressures in all stories and varying pressures in all stories. The third story had a 8 PSI pattern and the other stories had a 2 PSI pattern; all stories with 8 PSI patterns achieved the least displacement when compared to other variations. A monotonic static analysis was performed for both the experimental and analytical study. The boundary conditions were pinned, and coupling interfaces were made for the master and slave surfaces. The pressure conditions were applied in various linear and nonlinear patterns to optimize the pressure. A comparative study was performed on the displacement, stiffness, and drift ratio for the critical position of the interface pressure in both the analytical and experimental studies. The difference was approximately 0.53% in the analytical study and 0.37% in the experimental work. The optimization was performed using both an experimental model and an analytical model, which had an error percentage of 0.61%. [ABSTRACT FROM AUTHOR]

The aim of the study was to produce new elastomeric materials containing butyl rubber (IIR) filled with silica and phyllosilicates (vermiculite, montmorillonite, perlite or halloysite tubes) with enhanced hydrophobicity and barrier properties and reduced chemical degradation. It was found that the filler type had a significant impact on the degree of cross-linking of butyl rubber and the properties of its vulcanizates. The highest degree of cross-linking and the highest mechanical strength were achieved for IIR composites filled with Arsil with perlite or halloysite tubes. The highest surface hydrophobicity (119°) was confirmed for the IIR vulcanizates with Arsil and montmorillonite. All tested samples showed high barrier properties because both the gas diffusion rate coefficient and the permeability coefficient reached low values. Both unfilled and filled IIR vulcanizates retained chemical resistance in contact with methanol for 480 min. Hour-long contact of a polar solvent (methanol) with each of the vulcanizates did not cause material degradation, while the presence of a non-polar solvent (n-heptane) worsened the mechanical parameters by up to 80%. However, the presence of fillers reduced the chemical degradation of vulcanizates (in the case of cured IIR filled with Arsil and halloysite tubes by 40% compared to the composite without fillers).

The high elasticity and excellent gas barrier properties of rubber composites make them irreplaceable in the field of sealing. Constructing a complicated barrier network to reduce free volume is crucial to improving gas barrier properties. In this research, liquid acrylonitrile-butadiene rubber/γ-Methacryloxypropyl trimethoxy silane (KH570) modified graphene oxide/butyl rubber composites (LNBR/KGO/IIR) were fabricated. A KGO lamellar network was constructed to resist gas diffusion in the IIR matrix. Meanwhile, LNBR macromolecules further occupied the free volume inside the IIR composites, thereby maximizing the retardation of the path of small molecule gas permeation. The modification of GO by KH570 was successfully demonstrated through FTIR and XRD. The grafting rate of KH570 was calculated to be approximately 71.4%. KGO was well dispersed in IIR due to emulsion compounding and the formation of lamellar networks. The 300% modulus, tensile strength and tear strength of KGO/IIR were improved by 43.5%, 39.1% and 14.8%, respectively, compared to those of the IIR composite. In addition, the introduction of LNBR resulted in a 44.2% improvement in the gas barrier performance of nitrogen permeability relative to the original IIR composite.

A novel type of silica namely black sand (BS) with silane coupling agent was chosen as reinforcing filler in butyl rubber (IIR). BS was obtained from the beach area of Rosetta in Egypt. The filler was characterized by Fourier-transform infrared (FTIR), X-ray diffraction (XRD), and transmission electron microscope (TEM). The XRD analysis showed that BS is composed mainly of Albite (Sodium Aluminium Silicate) up to 64% approximately. Novel nanocomposites were prepared via a two-roll mill by incorporating different concentrations of BS nanoparticles (5,10, 15, 20,30 and 40 phr) in IIR. The effects of filler loading on shape factor, curing characteristics, and mechanical and dynamic properties of IIR vulcanizates were investigated. The modulus of IIR vulcanizates was used to predict the shape factor of BS aggregation in the polymer. The data indicated that cure time decreased with the increase in filler loading, and the change in scorch time is less. It was found that the shape factor is independent of the concentration. With an increase in the filler loading, tensile and elongation of the composites were significantly increased, especially at 30 phr. The bound rubber content increased with increasing BS content up to 30 phr exhibiting the rubber-filler interaction. The reinforcing factor, R (related to the difference in tan δ peak height at the glass transition temperature (Tg) for the filled and unfilled rubbers), also demonstrated that the BS-IIR interaction was stronger than for unfilled rubber. Since 30 phr black sand loaded IIR composite showed superior physical-mechanical properties. In general, the results indicated that the black sand filler was an effective reinforcement material for the butyl rubber. [ABSTRACT FROM AUTHOR]

Copyright of China Rubber Industry is the property of Editorial Office of China Rubber Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Silver nanowires (AgNWs) are leading materials for transparent conductive electrodes in optoelectronic devices. The solution processability of AgNWs combined with the optical transparency and electrical conductivity of solution-deposited AgNW networks makes them a promising alternative to conventional indium tin oxide. Furthermore, the ability of AgNW networks to withstand mechanical deformation means that AgNW networks may be the material of choice for next-generation flexible and stretchable optoelectronics. The drawback with the practical use of AgNWs, however, is that corrosion of AgNWs under ambient conditions damages the AgNW network and reduces the workable life span. Environmental degradation is especially problematic in stretchable electronics, which use elastomeric substrate materials that have a high gas permeability like poly-(dimethylsiloxane) (PDMS). Covering individual AgNWs with a protective nanoscale coating to prevent corrosion complexifies their preparation and implementation in practical applications. This study presents an alternative approach in which the elastomeric substrate, transparent butyl rubber (TBR), acts as both a stretchable substrate and a protective gas barrier. TBR, an optically transparent formulation of poly-(isobutylene-co-isoprene), is a synthetic rubber with an intrinsically low gas permeability. We demonstrate that AgNW networks embedded in a polyurethane adhesive and adhered to a TBR substrate provide high conductivity and optical transparency and are robust to tensile strain as well as extreme environments of humidified air, underwater storage, and corrosive acid vapors. We show that this system outperforms a comparison system that uses PDMS instead of TBR. [ABSTRACT FROM AUTHOR]

Electromagnetic properties of polymer composites strongly depend on the loading amount and the completeness of the filler's dispersive structure. Improving the compatibility of single-walled carbon nanotubes (SWCNTs) with isobutylene butyl rubber (IIR) is a good solution to mitigate aggregation. The change in configuration of poly-oxyethylene octyl phenol ether (OP-10) was induced using water as the exposed hydrophilic groups linking with water molecules. The SWCNT and IIR/SWCNT composites were then prepared via wetly-melt mixing at a relatively high temperature to remove water, and they were then mixed with other agents after vacuum drying and cured. The SWCNTs were dispersed uniformly to form a good network for a lower percolation threshold of the wave-absorbing property to 2 phr from 8 phr. With 8 phr SWCNTs, the tensile strength of the material improved significantly from 7.1 MPa to 15.1 MPa, and the total electromagnetic shielding effectiveness of the material was enhanced to 23.8 dB, a 3-fold increase compared to the melt-mixed material. It was demonstrated that water-induced modification achieved good dispersion of SWCNTs for electromagnetic shielding enhancement while maintaining a wide damping temperature range from −55 °C to 40 °C with a damping factor over 0.2. [ABSTRACT FROM AUTHOR]

Organic montmorillonite/brominated butyl rubber nanocomposites are prepared by improved solution blending, i.e., preparation of organic clay suspension and suspension blending with brominated butyl rubber solution by adding polytetramethylene ether glycol as interface agent. Scanning electron microscopy and atomic force microscopy show that polytetramethylene ether glycol has good dispersing effect on organic clay. Transmission electron microscopy and X‐ray diffraction analysis demonstrates that both intercalated and exfoliated structures are obtained in organic montmorillonite/brominated butyl rubber nanocomposites. The mechanical performances and the gas barrier properties of the organic montmorillonite/brominated butyl rubber nanocomposites are improved greatly, which proves that the high‐performance clay/rubber nanocomposites are prepared in nonpolar solvent. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pyrolysis of butyl rubber tube waste was performed under an inert nitrogen gas environment for temperature ranging between 25 and 1,000 °C, by varying the heating rates (5, 10, 20, 35, and 55 °C min-1). Five different isoconversional approaches, namely, Differential Friedman, Ozawa-Flynn-Wall, Kissinger-Akahira-Sunuse, Distributed activation, and Starink, were employed to investigate the kinetics and thermodynamic parameters. The mean activation energy (Eα), and pre-exponential factor (ko) varied between 222.67 and 244.73 kJ mol-1 and 6.82×1021 and 2.73×1024 s-1 respectively, for all iso-conversional approaches. From the kinetic investigation, a strong correlation co-efficient (R²>0.97) was ascertained in the conversion range of up to α=0.8 for all the isoconversational approaches. By thermodynamic analysis, the mean values of change in enthalpy and change in Gibbs free energy were 217.06-239.13 kJ mol-1 and 185.12-218.11, kJ mol-1, respectively. From the master plot analysis, diffusion model (D3), and several reaction order models (F1, F2, F3, and F5) were predicted throughout the conversion (0.1 to 0.8) limit at 20 °C min-1 for the pyrolysis of BRT. [ABSTRACT FROM AUTHOR]

Self-healing anticorrosive coatings in extreme environment have attracted considerable interest from researchers. In this work, 4-tert-butylpyridine (TBP) was incorporated into brominated butyl rubber (BIIR) polymer networks to form a reversible ionic bond with the highly reactive bromine anion. Based on the low glass transition temperature of the BIIR polymer and the electrostatic effects, a robust self-healing anticorrosive coating of TBP-BIIR was prepared. TBP-BIIR coating showed a maximum protection efficiency (PE) of more than 94% (TBP-BIIR-acid, 94.37%; TBP-BIIR-alkali, 94.95%; TBP-BIIR-salt, 95.49%) when treated with a strong acid (HNO3, pH=2), strong base (NaOH, pH=12) and high salt solution (3.5 wt% NaCl). In addition, the PE of coating repaired exceed 89%, and the maximum PE value was approximately 95% in different solutions, which demonstrated its extinguished self-healing abilities. These results indicated that the TBP-BIIR anticorrosive coating could provide excellent safety and durability in special environment, which would be extremely beneficial to improve the working life of metal parts used in aviation and shipping, oil and gas and related industries. [ABSTRACT FROM AUTHOR]

Flexible self-healing composite was fabricated based on blending the bromobutyl rubber (BIIR) and epoxide natural rubber (ENR) filled with hybrid fillers of carbon nanotubes (CNT) and carbon black (CB). To achieve self-recoverability, modification of BIIR was carried out through butyl imidazole (IM), and the healing capability was then activated by the addition of bis(triethoxysilylpropyl)tetrasulfide (TESPT), which resulted in good dispersion of CNT/CB in BIIR/ENR blends. The silanization of TESPT and CNT/CB hybrid filler surfaces was confirmed by attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. Adding CNT/CB and incorporating TESPT into the composites effectively improved the curing and mechanical properties of the blends in terms of estimated crosslink density and tensile modulus. Further, the self-healing propagation rate was enhanced by the thermal conductivity of fillers and the ion–dipole intermolecular forces between the rubber chains, leading to the highest abrasion resistance and electrical conductivity. Using an environmentally friendly process, the recyclability of the self-healing composites was improved by the re-compression of the samples. With this, the constant conductivity relating to the rearrangement of the CNT/CB network is examined related to the usability of the composites at 0 and 60 °C. The conductive composites filled with a TESPT silane coupling agent present an opportunity for vehicle tires and other self-repairing applications. [ABSTRACT FROM AUTHOR]

This paper investigates the influence of an alternating multi-layered design on the material loss factor and effective temperature range of free/constrained-damping butyl rubber, and then proposes a new method of designing materials with high damping properties and a wide temperature range. First, the wide-temperature rubber IIR-0, the low-temperature rubber IIR-1, the medium-temperature rubber IIR-2, and the high-temperature rubber IIR-3 are prepared and characterized. Second, the influences of an alternating multi-layered design on the damping peak values and temperature range of free damping and micro-constrained damping of the rubber types are investigated. Finally, different methods for broadening the damping temperature range and improving the damping loss factor are discussed. The results show that the loss factor of the alternating multi-layered, constrained damping structure is increased to 0.488, while that of the free-damping structure is increased to 0.845. Their damping-temperature ranges are increased to 89.4 °C and 93.2 °C, respectively. A wide temperature range and high damping performance can be achieved by the alternating multi-layered design of rubber/plastic micro-constrained damping composites. [ABSTRACT FROM AUTHOR]

In this study, a modified Rayleigh–Lamb equation is derived that takes into account the radial oscillations of a gas bubble covered with a viscoelastic shell and an inner thin liquid layer is distributed. For the case of small perturbations, a dispersion equation is found that takes into account the interfacial heat transfer between the gas, liquid layer, viscoelastic shell, and carrier fluid. An analytical expression for the equilibrium speed of sound is written out, and its dependence on the dimensions of the liquid layer, viscoelastic shell, and frequency of perturbations is established. The difference in the size of the inner liquid layer in shell bubble on the dynamics of acoustic waves is illustrated. The influence of the dependences of the shear modulus and viscosity of butyl rubber on the frequency of perturbations at different temperatures on the curves of the phase velocity and damping coefficient is shown. The theory is compared with the experimental data. [ABSTRACT FROM AUTHOR]

The recycling of zinc compound from waste tires and the negative impact of zinc oxide on environment have been major challenges in rubber industry. In this study, the components and microstructure of recovered carbon black (rCB) from waste tires pyrolysis are analyzed, in which the content of the ash and zinc element is 20 % and 6.1 %, and zinc sulfide is the main zinc compound. Zinc sulfide and zinc oxide could crosslink brominated butyl rubber (BIIR), and the crosslinking effect becomes more effective in the presence of carbon black N660. BIIR can be crosslinked and reinforced by rCB in the absence of other additives. BIIR/rCB composites have similar curing behavior and mechanical properties to the BIIR composites filled with N660 and cured by zine oxide. Therefore, rCB could replace commercial carbon black N660 and zinc oxide in BIIR, and this replacement will realize the effective use of carbon black and zinc compound in rCB from waste tires and promote the sustainable development of tire industry. [Display omitted] • The content of Zn was 6.1 %, and rCB contains Nano-sized zinc-containing compound. • ZnS was the main zinc-containing compound in rCB, and rCB can be used to effectively crosslink BIIR. • ZnS could play a similar role as ZnO in BIIR/N660 compound. • BIIR/rCB composite without adding ZnO had good performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • A monovalent anion perm-selective membrane was successfully scaled up. • The perm-selectivity for (F-, Cl-, SO 4 2- and NO 3 -)/SO 4 2- is 5.1, 15.1, 17.5, and 21. • The membrane achieved outstanding salt concentration performance (18.6 wt%). • Selective electrodialysis was used to treat brominated butyl rubber wastewater. • Obtained NaBr product with a concentration ratio of 6.2 and a purity of 97.8%. Selective electrodialysis (SED) technology utilizing monovalent anion perm-selective membranes (MAPMs) has potential in resource recovery and wastewater treatment. However, the development and production of homogeneous MAPMs with high performance and scalability pose significant challenges. This study successfully scaling up a poly(alkyl-biphenyl pyridinium)-based MAPM suitable for large-scale SED applications and applies it to the treatment of mono-/di-valent anion wastewater. The pilot-scale membrane exhibits significantly higher perm-selectivity for various mixed anion systems compared to the commercial ACS membrane, and under the conditions of a current density of 40 mA cm−2, an initial dilute chamber solution of 3 L 0.5 mol/L NaCl, and a constant concentration chamber volume of 0.2 L, the pilot-scale membrane achieves a salt (NaCl) concentration of 18.6 wt% in just 70 mins in the membrane stack, with an energy consumption of 0.38 kWh kg−1. Furthermore, simulated brominated butyl rubber wastewater is treated with the aim of refining NaBr and separating SO 4 2- ions. Several factors, such as applied voltage, initial concentration of the dilute chamber solution, feed flow rate, and dilute-to-concentrated chamber volume ratio are investigated to assess their effects on the treatment results. By continuously optimizing the operating conditions, a NaBr product with a concentration ratio of 6.2 and a purity of 97.8 % was obtained, with the Br- ion flux of 3.24 mol m-2 h−1 and an energy consumption of 0.319 kWh kg−1. [ABSTRACT FROM AUTHOR]