Rubbers and Elastomers Materials

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Polymers polymers	4.7	8.0	2009	14.5 Days	CHF 2700
Materials materials	3.1	5.8	2008	15.5 Days	CHF 2600
Journal of Composites Science jcs	3.0	5.0	2017	18.5 Days	CHF 1800
Solids solids	2.4	3.4	2020	20.5 Days	CHF 1000

14 pages, 1741 KiB

Open AccessReview

Recycling Functional Fillers from Waste Tires for Tailored Polystyrene Composites: Mechanical, Fire Retarding, Electromagnetic Field Shielding, and Acoustic Insulation Properties—A Short Review

by Jinlong Zhang, Hang Liu, Shyam S. Sablani and Qinglin Wu

Materials 2024, 17(11), 2675; https://doi.org/10.3390/ma17112675 - 1 Jun 2024

Cited by 1 | Viewed by 1444

Abstract

Polymer waste is currently a big and challenging issue throughout the world. Waste tires represent an important source of polymer waste. Therefore, it is highly desirable to recycle functional fillers from waste tires to develop composite materials for advanced applications. The primary theme [...] Read more.

Polymer waste is currently a big and challenging issue throughout the world. Waste tires represent an important source of polymer waste. Therefore, it is highly desirable to recycle functional fillers from waste tires to develop composite materials for advanced applications. The primary theme of this review involves an overview of developing polystyrene (PS) composites using materials from recycled tires as fillers; waste tire recycling in terms of ground tire rubbers, carbon black, and textile fibers; surface treatments of the fillers to optimize various composite properties; and the mechanical, fire retarding, acoustic, and electromagnetic field (EMI) shielding performances of PS composite materials. The development of composite materials from polystyrene and recycled waste tires provides a novel avenue to achieve reductions in carbon emission goals and closed-loop plastic recycling, which is of significance in the development of circular economics and an environmentally friendly society. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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18 pages, 9397 KiB

Open AccessArticle

Enhancing the Cooling Efficiency of Aluminum-Filled Epoxy Resin Rapid Tool by Changing Inner Surface Roughness of Cooling Channels

by Chil-Chyuan Kuo, Hong-Wei Chen, Geng-Feng Lin, Song-Hua Huang and Shih-Feng Tseng

Polymers 2024, 16(7), 874; https://doi.org/10.3390/polym16070874 - 22 Mar 2024

Viewed by 1227

Abstract

In low-pressure wax injection molding, cooling time refers to the period during which the molten plastic inside the mold solidifies and cools down to a temperature where it can be safely ejected without deformation. However, cooling efficiency for the mass production of injection-molded [...] Read more.

In low-pressure wax injection molding, cooling time refers to the period during which the molten plastic inside the mold solidifies and cools down to a temperature where it can be safely ejected without deformation. However, cooling efficiency for the mass production of injection-molded wax patterns is crucial. This work aims to investigate the impact of varying surface roughness on the inner walls of the cooling channel on the cooling efficiency of an aluminum-filled epoxy resin rapid tool. It was found that the cooling time for the injection-molded products can be determined by the surface roughness according to the proposed prediction equation. Employing fiber laser processing on high-speed steel rods allows for the creation of microstructures with different surface roughness levels. Results demonstrate a clear link between the surface roughness of cooling channel walls and cooling time for molded wax patterns. Employing an aluminum-filled epoxy resin rapid tool with a surface roughness of 4.9 µm for low-pressure wax injection molding can save time, with a cooling efficiency improvement of approximately 34%. Utilizing an aluminum-filled epoxy resin rapid tool with a surface roughness of 4.9 µm on the inner walls of the cooling channel can save the cooling time by up to approximately 60%. These findings underscore the significant role of cooling channel surface roughness in optimizing injection molding processes for enhanced efficiency. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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17 pages, 4172 KiB

Open AccessArticle

Design and Study of Novel Composites Based on EPDM Rubber Containing Bismuth (III) Oxide and Graphene Nanoplatelets for Gamma Radiation Shielding

by Gabriela Álvarez-Cortez, Francisco Molina, Bruno F. Urbano, Mohamed Dahrouch, Marianella Hernández Santana, Miguel A. Lopez Manchado, Raquel Verdejo and Héctor Aguilar Bolados

Polymers 2024, 16(5), 633; https://doi.org/10.3390/polym16050633 - 26 Feb 2024

Cited by 2 | Viewed by 1625

Abstract

The mechanical, thermal and gamma radiation attenuation properties of ethylene–propylene–diene monomer (EPDM)-based composites containing graphene nanoplatelets (GNs) and bismuth (III) oxide nanoparticles (B) were investigated. The use of polyethylene glycol (PEG) as a compatibilizer to improve the dispersion of the fillers was also [...] Read more.

The mechanical, thermal and gamma radiation attenuation properties of ethylene–propylene–diene monomer (EPDM)-based composites containing graphene nanoplatelets (GNs) and bismuth (III) oxide nanoparticles (B) were investigated. The use of polyethylene glycol (PEG) as a compatibilizer to improve the dispersion of the fillers was also investigated. The results showed that the combined use of these fillers resulted in a drastic increase in mechanical properties, reaching 123% and 83% of tensile strength and elongation at break, respectively, compared to those of EPDM. In contrast, the addition of PEG to composites containing EPDM GNs and B resulted in composites with lower values of mechanical properties compared to the EPDM/B/GN-based composite. However, the presence of PEG leads to obtaining a composite (EPDM/B/GNP) with a mass attenuation coefficient to gamma radiation (¹³⁷Cs, 662 keV) superior to that composite without PEG. In addition, the composite EPDM, B and PEG exhibited an elongation at break 153% superior to unfilled EPDM. Moreover, the binary filler system consisting of 100 phr of bismuth (III) oxide and 10 phr of GN leads to reaching 61% of the linear damping coefficient of the EPDM composite compared to that value of the unfilled EPDM. The study of the morphology and the state of filler dispersion in the polymer matrix, obtained using scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively, provides a useful background for understanding the factors affecting the gamma radiation attenuation properties. Finally, the results also indicated that by adjusting the formulation, it is possible to tune the mechanical and thermal properties of EPDM composites reinforced with bismuth oxide and graphene nanoplatelets. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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2 pages, 307 KiB

Open AccessCorrection

Correction: Smejda-Krzewicka et al. Interelastomer Reactions Occurring during the Cross-Linking of Hydrogenated Acrylonitrile-Butadiene (HNBR) and Chloroprene (CR) Rubbers Blends in the Presence of Silver(I) Oxide (Ag₂O) and Mechanical Properties of Cured Products. Materials 2023, 16, 4573

by Aleksandra Smejda-Krzewicka, Konrad Mrozowski and Krzysztof Strzelec

Materials 2024, 17(5), 1021; https://doi.org/10.3390/ma17051021 - 23 Feb 2024

Viewed by 610

Abstract

In the original publication [...] Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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18 pages, 3666 KiB

Open AccessArticle

Development of a Silicone Rubber Mold with an Innovative Waterfall Cooling Channel

by Chil-Chyuan Kuo, Pin-Han Lin, Jing-Yan Xu, Zhe-Xhi Lin, Zi-Huan Wang, Zhi-Jun Lai and Song-Hua Huang

Polymers 2024, 16(2), 256; https://doi.org/10.3390/polym16020256 - 16 Jan 2024

Cited by 2 | Viewed by 1229

Abstract

A conformal cooling channel (CCC) follows the mold core or cavity profile to carry out uniform cooling in the cooling stage. However, the significant pressure drop along the cooling channels is a distinct disadvantage of the CCC. In this study, an innovative waterfall [...] Read more.

A conformal cooling channel (CCC) follows the mold core or cavity profile to carry out uniform cooling in the cooling stage. However, the significant pressure drop along the cooling channels is a distinct disadvantage of the CCC. In this study, an innovative waterfall cooling channel (WCC) was proposed and implemented. The WCC cools the injected products via surface contact, replacing the conventional line contact to cool the injected products. The WCC was optimized using numerical simulation software. Silicone rubber molds with two kinds of cooling channels were designed and implemented. The cooling time of the molded part was evaluated using a low-pressure wax injection molding machine. The experimental results of the cooling time of the molded part were compared with the simulation results from numerical simulation software. The results showed that the optimal mesh element count was about 1,550,000 with a mesh size of 1 mm. The simulation software predicted the filling time of the water cup injection-molded product to be approximately 2.008 s. The cooling efficiency for a silicone rubber mold with a WCC is better than that of the silicone rubber mold with a CCC since the core and cavity cooling efficiency is close to 50%. The pressure drop of the WCC is smaller than that of the CCC, which reduces the pressure drop by about 56%. Taking a water cup with a mouth diameter of 70 mm, a height of 60 mm, and a thickness of 2 mm as an example, the experimental results confirmed that the use of the WCC can save the cooling time of the product by about 265 s compared with the CCC. This shows how a WCC can increase cooling efficiency by approximately 17.47%. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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13 pages, 5268 KiB

Open AccessArticle

Changes in the Optical Properties of Rubber Exposed to High-Pressure Hydrogen Using Pulsed Terahertz Waves

by Mun-Young Hwang, Hyun Chul Lee, Hyeok-Jae Yang and Dae-Hyun Han

Polymers 2023, 15(23), 4530; https://doi.org/10.3390/polym15234530 - 25 Nov 2023

Viewed by 1140

Abstract

In this study, we investigated how high-temperature, high-pressure hydrogen affects the optical properties of three kinds of sealing rubber (chloroprene rubber, ethylene propylene diene monomer, and acrylonitrile butadiene rubber) using pulsed terahertz waves. The optical properties of the rubber samples were analyzed before [...] Read more.

In this study, we investigated how high-temperature, high-pressure hydrogen affects the optical properties of three kinds of sealing rubber (chloroprene rubber, ethylene propylene diene monomer, and acrylonitrile butadiene rubber) using pulsed terahertz waves. The optical properties of the rubber samples were analyzed before and after exposure to hydrogen (80 °C and 200 bar) for 72 h. The results showed that the terahertz waves had a shorter time delay and a lower signal intensity for all rubber types. The exposure response intensity, refractive index, and absorption rate also changed in the frequency domain. Raman and Fourier transform infrared spectroscopy were used for comparison, and a few peak shifts were observed. However, the Raman spectra had low signal quality, and the laser damaged the specimen. The study demonstrates that terahertz waves can be used as a non-contact non-destructive testing technique to evaluate the changes in sealing rubbers after hydrogen exposure. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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14 pages, 8083 KiB

Open AccessArticle

Improved Thermal Insulation and Mechanical Strength of Styrene-Butadiene Rubber through the Combination of Filled Silica Aerogels and Modified Glass Fiber

by Guofeng Wang, Wenwen Yu, Sitong Zhang, Kaijie Yang, Wenying Liu, Jiaqi Wang and Fuyong Liu

Materials 2023, 16(17), 5947; https://doi.org/10.3390/ma16175947 - 30 Aug 2023

Cited by 3 | Viewed by 1679

Abstract

To improve heat dissipation capability and enhance mechanical properties, a series of silica aerogel (SA) and modified glass fiber (GF)-filled SBR composites were prepared. It was found that the addition of SA successfully reduced the thermal conductivity of SBR by 35%, owing to [...] Read more.

To improve heat dissipation capability and enhance mechanical properties, a series of silica aerogel (SA) and modified glass fiber (GF)-filled SBR composites were prepared. It was found that the addition of SA successfully reduced the thermal conductivity of SBR by 35%, owing to the heat shield of the nanoscale porous structure of SA. Moreover, the addition of modified glass fiber (MGF) yielded a significant increase in the tensile and tear strength of SBR/SA composite rubber of 37% and 15%, respectively. This enhancement was more pronounced than the improvement observed with unmodified GF, and was attributed to the improved dispersion of fillers and crosslinking density of the SBR matrix. Rheological analysis revealed that the addition of SA and MGF weakened the ω dependence. This was due to the partial relaxation of immobilized rubber chains and limited relaxation of rubber chains adsorbed on the MGF. Furthermore, the strain amplification effect of MGF was stronger than that of GF, leading to a more pronounced reinforcing effect. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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25 pages, 4533 KiB

Open AccessArticle

Interelastomer Reactions Occurring during the Cross-Linking of Hydrogenated Acrylonitrile-Butadiene (HNBR) and Chloroprene (CR) Rubbers Blends in the Presence of Silver(I) Oxide (Ag₂O) and Mechanical Properties of Cured Products

by Aleksandra Smejda-Krzewicka, Konrad Mrozowski and Krzysztof Strzelec

Materials 2023, 16(13), 4573; https://doi.org/10.3390/ma16134573 - 25 Jun 2023

Cited by 3 | Viewed by 1369 | Correction

Abstract

The purpose of this paper was to examine the possibility of producing new blends of hydrogenated acrylonitrile-butadiene and chloroprene rubbers (HNBR/CR) unconventionally cross-linked with silver(I) oxide (Ag₂O), and to investigate the physicomechanical properties of the obtained materials. From the obtained results, [...] Read more.

The purpose of this paper was to examine the possibility of producing new blends of hydrogenated acrylonitrile-butadiene and chloroprene rubbers (HNBR/CR) unconventionally cross-linked with silver(I) oxide (Ag₂O), and to investigate the physicomechanical properties of the obtained materials. From the obtained results, it can be concluded that HNBR/CR composites were effectively cured with Ag₂O, which led to interelastomer reactions, and the degree of binding of HNBR with CR was in the range of 14–59%. The rheometric and equilibrium swelling studies revealed that the cross-linking progress depended on the weight proportion of both elastomers, and the degree of cross-linking was greater with more content of chloroprene rubber in the tested blends. Interelastomer reactions occurring between HNBR and CR improved the homogeneity and miscibility of the tested compositions, which was confirmed by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) analyses. The tensile strength and hardness of the obtained HNBR/CR/Ag₂O vulcanizates proportionally increased with the content of CR, while the tear strength showed an inverse relationship. The obtained new, unconventional materials were characterized by significant resistance to thermo-oxidative factors, which was confirmed by the high aging factor. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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15 pages, 18296 KiB

Open AccessArticle

Control of Tire Wear Particulate Matter through Tire Tread Prescription

by Jin U. Ha, Seok H. Bae, Yu J. Choi, Pyoung-Chan Lee, Sun K. Jeoung, Sanghoon Song, Choong Choi, Jae S. Lee, Jaeyun Kim and In S. Han

Polymers 2023, 15(13), 2795; https://doi.org/10.3390/polym15132795 - 23 Jun 2023

Cited by 2 | Viewed by 1976

Abstract

This study aims to analyze tire wear particulate matter (TWP) from tread rubber with different formulations and to compare the concentration of TWP with different wear devices. The TWP generated during the abrasion of truck and bus radial (TBR) tires were examined, and [...] Read more.

This study aims to analyze tire wear particulate matter (TWP) from tread rubber with different formulations and to compare the concentration of TWP with different wear devices. The TWP generated during the abrasion of truck and bus radial (TBR) tires were examined, and the effect of using different types of rubber and carbon black (CB) were investigated. When natural rubber (NR) was solely used as the tire tread rubber material, there was a higher concentration of 5–10 µm TWP. However, when the tread formulation consisted of NR mixed with butadiene rubber, the TWP concentration decreased. Changing the type of CB also reduced the amount of TWP in the 2.5 µm size range. The TWP concentration in the specimens increased with increasing speed and vertical load. The TWP generated during the abrasion tests using wear testers and tire simulators exhibited similar trends. These findings suggest that modifying tire tread formulations can effectively control the distribution and amount of TWP generation. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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17 pages, 5005 KiB

Open AccessArticle

The Particle Breakage Effect on Abrasive Wear Process of Rubber/Steel Seal Pairs under High/Low Pressure

by Ziyi Zhou, Qin Zhou, Kun Qin, Shuaishuai Li, Kai Zhang, Tongxin Yuan and Weihao Sun

Polymers 2023, 15(8), 1857; https://doi.org/10.3390/polym15081857 - 12 Apr 2023

Cited by 4 | Viewed by 2219

Abstract

Pressure has a significant effect on rubber seal performance in the abrasive environments of drilling. The micro-clastic rocks intruding into the seal interface are prone to fracture, which will change the wear process and mechanism, but this process is not yet known at [...] Read more.

Pressure has a significant effect on rubber seal performance in the abrasive environments of drilling. The micro-clastic rocks intruding into the seal interface are prone to fracture, which will change the wear process and mechanism, but this process is not yet known at present. To explore this issue, abrasive wear tests were carried out to compare the failure characteristics of the particles and the variation wear process under high/low pressures. The results show that non-round particles are prone to fracture under different pressures, resulting in different damage patterns and wear loss on the rubber surface. A single particle force model was established at the soft rubber–hard metal interface. Three typical breakage types of particles were analyzed, including ground, partially fractured, and crushed. At high load, more particles were crushed, while at low load, shear failure was more likely to occur at the edges of particles. These different particle fracture characteristics not only change the particle size, but also the state of motion and thus the subsequent friction and wear processes. Therefore, the tribological behavior and wear mechanism of abrasive wear are different at high pressure and low pressure. Higher pressure reduces the invasion of the abrasive particles, but also intensifies the tearing and wear of the rubber. However, no significant differences in damage were found for steel counterpart throughout the wear process under high/low load tests. These results are critical to understanding the abrasive wear of rubber seals in drilling engineering. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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15 pages, 3060 KiB

Open AccessArticle

Pyrolysis and Oxidative Thermal Decomposition Investigations of Tennis Ball Rubber Wastes through Kinetic and Thermodynamic Evaluations

by Hai-Bo Wan and Zhen Huang

Materials 2023, 16(6), 2328; https://doi.org/10.3390/ma16062328 - 14 Mar 2023

Cited by 1 | Viewed by 1443

Abstract

Thermal decomposition of tennis ball rubber (TBR) wastes in nitrogen and air has been studied through thermogravimetric analysis. The samples were thermally decomposed from room temperature to 950 K at heating rates of 3 to 20 K/min with a purging flow of 30 [...] Read more.

Thermal decomposition of tennis ball rubber (TBR) wastes in nitrogen and air has been studied through thermogravimetric analysis. The samples were thermally decomposed from room temperature to 950 K at heating rates of 3 to 20 K/min with a purging flow of 30 cm³/min. The degradation features and specific temperatures for two purging gases are thus compared according to the nonisothermal results. Kinetic analyses of two thermal decomposition processes have been isoconversionally performed using differential or integral methods. The activation energy as a function of mass conversion has been thus obtained over the entire decomposition range, varying from 116.7 to 723.3 kJ/mol for pyrolysis and 98.2 to 383.6 kJ/mol for oxidative thermal decomposition. The iterative Flynn–Wall–Ozawa method combined with the linear compensation effect relationship has been proposed for determining the pre-exponential factor and reaction mechanism function, resulting in chemical order reaction models of f(α) = (1 − α)^5.7 and f(α) = (1 − α)^5.8 for describing pyrolysis and the oxidative thermal degradation of TBR wastes, respectively. With these kinetic parameters, very satisfactory matching against experimental data has been obtained for both gases. Additionally, the thermodynamic parameters, such as the changes of entropy, enthalpy and Gibbs free energy, over the whole thermal degradation processes have also been evaluated. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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12 pages, 2902 KiB

Open AccessArticle

Effects of Ethylene-Propylene-Diene Monomers (EPDMs) with Different Moony Viscosity on Crystallization Behavior, Structure, and Mechanical Properties of Thermoplastic Vulcanizates (TPVs)

by Li-Fu Song, Nan Bai, Ying Shi, Yuan-Xia Wang, Li-Xin Song and Li-Zhi Liu

Polymers 2023, 15(3), 642; https://doi.org/10.3390/polym15030642 - 26 Jan 2023

Cited by 7 | Viewed by 3277

Abstract

Moony viscosity of ethylene-propylene-diene monomers (EPDMs) can have effect on the crystallization dynamics, structure, and properties of EPDM/polypropylene (PP)-based thermoplastic vulcanizates (TPVs). TPVs with two different Moony viscosities are prepared via a twin-screw extruder, respectively. Crosslinked EPDM with lower Moony viscosity has a [...] Read more.

Moony viscosity of ethylene-propylene-diene monomers (EPDMs) can have effect on the crystallization dynamics, structure, and properties of EPDM/polypropylene (PP)-based thermoplastic vulcanizates (TPVs). TPVs with two different Moony viscosities are prepared via a twin-screw extruder, respectively. Crosslinked EPDM with lower Moony viscosity has a higher crosslinking density and the nucleation effect of its crosslink point improves the crystallization ability of PP in TPV, leading to PP phase crystallization at higher temperatures. For TPV with an EPDM of higher Moony viscosity, it has higher crystallinity and the EPDM phase crystallized earlier. Synchrotron radiation studies show that the EPDM with low Moony viscosity has no obvious crystalline structure, and the prepared TPV has an obvious phase separation structure, while the TPV with higher Mooney viscosity of the EPDM does not exhibit obvious phase separation, indicating that the longer EPDM chains have better compatibility with PP in TPV, also evidenced by the almost disappearance of the PP glass transition peak in TPV, from the dynamic mechanical analysis. The longer EPDM chains in TPV provide more physical entanglement and better interaction with PP molecules, resulting in a stronger strain hardening process, longer elongation at break, and higher tensile stress in TPV. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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16 pages, 6718 KiB

Open AccessArticle

Increase in Properties and Self-Healing Ability of Conductive Butyl Rubber/Epoxidized Natural Rubber Composites by Using Bis(triethoxysilylpropyl)tetrasulfide Coupling Agent

by Piyawadee Luangchuang, Kunakorn Chumnum, Ekwipoo Kalkornsurapranee and Yeampon Nakaramontri

Polymers 2023, 15(3), 547; https://doi.org/10.3390/polym15030547 - 20 Jan 2023

Cited by 2 | Viewed by 2285

Abstract

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 [...] Read more.

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. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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16 pages, 4592 KiB

Open AccessArticle

Dynamic Characteristics of Rubber Reinforced Expansive Soil (ESR) at Positive and Negative Ambient Temperatures

by Jianhang Lv, Zhongnian Yang, Wei Shi, Zhaochi Lu, Qi Zhang and Xianzhang Ling

Polymers 2022, 14(19), 3985; https://doi.org/10.3390/polym14193985 - 23 Sep 2022

Cited by 7 | Viewed by 2006

Abstract

Using tire waste rubber reinforced expansive soil (ESR) can modify its poor engineering characteristics. The damping properties of ESR at different temperatures may vary dramatically. Two kinds of rubber R_a (large particle size) and R_b (small particle size) are mixed with [...] Read more.

Using tire waste rubber reinforced expansive soil (ESR) can modify its poor engineering characteristics. The damping properties of ESR at different temperatures may vary dramatically. Two kinds of rubber R_a (large particle size) and R_b (small particle size) are mixed with expansive soil according to gradient ratio. The backbone curves, dynamic shear modulus, and damping ratio of expansive soil in varying temperature fields of 20 °C, −5 °C, and −15 °C are investigated. The Hardin-Drnevich model can well fit the backbone curves of ESR specimens in various temperature fields. Dynamic triaxial results show that 5–10% R_a rubber can withstand higher shear stress in all temperature fields; R_b rubber can increase the dynamic shear modulus of expansive soil and reach the peak value with 10% rubber content. The damping ratio can be significantly improved by using 10% R_a rubber at room temperature, while the ESR damping ratio in a temperature field of −5 °C does not change significantly with increasing shear strain or even decreases; R_a increases the damping ratio of expansive soils in the temperature field of 15 °C while small particle size R_b decreases the damping ratio of expansive soils. The experimental results validate the effectiveness of ESR in the frozen soil area. In an engineering sense, local temperature needs to be considered to use an appropriate ESR, which can provide effective seismic isolation and damping. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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16 pages, 7410 KiB

Open AccessArticle

Investigation of Physical and Mechanical Characteristics of Rubber Materials Exposed to High-Pressure Hydrogen

by Sang Koo Jeon, Jae Kap Jung, Nak Kwan Chung, Un Bong Baek and Seung Hoon Nahm

Polymers 2022, 14(11), 2233; https://doi.org/10.3390/polym14112233 - 31 May 2022

Cited by 13 | Viewed by 3243

Abstract

Rubber materials play a key role in preventing hydrogen gas leakage in high-pressure hydrogen facilities. Therefore, it is necessary to investigate rubber materials exposed to high-pressure hydrogen to ensure operational safety. In this study, permeation, volume swelling, hydrogen content, and mechanical characteristics of [...] Read more.

Rubber materials play a key role in preventing hydrogen gas leakage in high-pressure hydrogen facilities. Therefore, it is necessary to investigate rubber materials exposed to high-pressure hydrogen to ensure operational safety. In this study, permeation, volume swelling, hydrogen content, and mechanical characteristics of acrylonitrile butadiene rubber (NBR), ethylene propylene diene monomer (EPDM), and fluorocarbon (FKM) samples exposed to pressures of 35 and 70 MPa were investigated. The results showed that the volume recovery and hydrogen desorption behavior of EPDM with the highest permeation were fast whereas those of FKM with the lowest permeation were slow. The volume of NBR with the highest hydrogen content expanded after decompression. In contrast, FKM swelled the most despite having the lowest hydrogen content. After exposure to high-pressure hydrogen, the compression set (CS) slightly increased due to internal cracks, but the tensile strength decreased significantly with increasing pressure despite the absence of cracks in the fracture area of all tensile specimens. It was concluded that the decrease in tensile strength is closely related to the volume increase because of the relationship between the relative true strength and the volume ratio. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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13 pages, 6632 KiB

Open AccessArticle

Structure and Dielectric Properties of TPU Composite Filled with CNTs@PDA Nanofibers and MXene Nanosheets

by Zhaoxia Luo, Xiaolin Li, Suhe Zhao, Lianghua Xu and Li Liu

Polymers 2022, 14(11), 2157; https://doi.org/10.3390/polym14112157 - 26 May 2022

Cited by 6 | Viewed by 3182

Abstract

Thermoplastic polyurethane (TPU) is a kind of dielectric elastomer (DE) which can behave as an actuator, altering thickness strain in response to electrical stimulation. The composites are made up of fillers with a very high dielectric constant that are spread in a polymer [...] Read more.

Thermoplastic polyurethane (TPU) is a kind of dielectric elastomer (DE) which can behave as an actuator, altering thickness strain in response to electrical stimulation. The composites are made up of fillers with a very high dielectric constant that are spread in a polymer matrix. It is very difficult to obtain large deformation at low voltage. In this study, we made two-dimensional (2D) MXene nanosheets with excellent conductivity and one-dimensional (1D) polydopamine (PDA)-modified CNT fiber fillers. After that, TPU dielectric elastomer films made of MXene/CNTs or MXene/CNTs@PDA were prepared. The results showed that the dielectric constant and dielectric loss of TPU dielectric film including MXene/CNTs were much higher than that containing MXene/CNTs@PDA, although Young’s modulus and breakdown strength (E_b) were significantly lower. At the same time, these two types of dielectric films had a significantly higher dielectric constant and dielectric loss than pure TPU dielectric film, and their breakdown strength was significantly lower. The compatibility of CNTs@PDA fibers with the TPU matrix improves after PDA modification, and the dispersion of CNTs@PDA fibers improves, resulting in an increase in Young’s modulus. MXene with a two-dimensional nanosheet structure increases the breakdown strength of the TPU dielectric elastomer under the condition of the addition of a tiny quantity. To summarize, the dielectric constant, dielectric loss, Young’s modulus, and dielectric elastomer breakdown strength are mutually restrictive conditions, and the relationship between all parties must be balanced to obtain obvious deformation properties. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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23 pages, 6956 KiB

Open AccessArticle

Experimental Study on the Characterization of Orientation of Polyester Short Fibers in Rubber Composites by an X-ray Three-Dimensional Microscope

by Benhui Yu, Jianbin Ren, Kongshuo Wang, Chuansheng Wang and Huiguang Bian

Materials 2022, 15(10), 3726; https://doi.org/10.3390/ma15103726 - 23 May 2022

Viewed by 2531

Abstract

Polyester-short-fiber-reinforced rubber composites have been detected by an X-ray three-dimensional microscope, and then the three-dimensional reconstruction of the image has been carried out to characterize the orientation of polyester short fibers in the composites for the first time. Based on the summary of [...] Read more.

Polyester-short-fiber-reinforced rubber composites have been detected by an X-ray three-dimensional microscope, and then the three-dimensional reconstruction of the image has been carried out to characterize the orientation of polyester short fibers in the composites for the first time. Based on the summary of three traditional methods and mechanisms of characterizing the orientation of polyester short fibers by the numerical parameter method, the direct test method, and the indirect test method, the method and mechanism of the X-ray three-dimensional microscope applied to the orientation characterization of polyester short fibers have been studied. The combination of the center point and threshold segmentation methods has been used to distinguish which fiber section belongs to the same fiber, and the identification of the whole short fiber in different slice images has been realized for the first time. Moreover, Avizo software has been used to realize the three-dimensional reconstruction of a polyester short fiber scanning image. The obtained data have been integrated and the orientation angle and orientation degree have been quantitatively characterized for the first time. This has filled the key technical problem of quantitative characterization of the orientation angle and orientation degree of polyester fibers. The image has been verified by 3Dmed software, and furthermore, the accuracy of the three-dimensional reconstruction results has been verified. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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19 pages, 5034 KiB

Open AccessArticle

Magneto-Dielectric Effects in Polyurethane Sponge Modified with Carbonyl Iron for Applications in Low-Cost Magnetic Sensors

by Ioan Bica and Gabriela-Eugenia Iacobescu

Polymers 2022, 14(10), 2062; https://doi.org/10.3390/polym14102062 - 18 May 2022

Cited by 5 | Viewed by 1941

Abstract

In this study, magnetizable polyurethane sponges (MSs) were obtained from commercial absorbent polyurethane sponges (PSs) doped with carbonyl iron microparticles (CIPs). Based on MSs, we manufactured cylindrical capacitors (CCs). The CCs were subjected to both a magnetic field and an alternating electric field, [...] Read more.

In this study, magnetizable polyurethane sponges (MSs) were obtained from commercial absorbent polyurethane sponges (PSs) doped with carbonyl iron microparticles (CIPs). Based on MSs, we manufactured cylindrical capacitors (CCs). The CCs were subjected to both a magnetic field and an alternating electric field, with a frequency of

f = 1 kHz

. Using an RLC bridge, we measured the series electric capacitance,

C_{s}

, and the tangent of the loss angle,

D_{s}

. From the functions

C_{s} = C_{s} {(δ)}_{C C s}

and

D_{s} = D_{s} {(δ)}_{C C s}

, we extracted the components of the complex dielectric permittivity. It was found that the CIPs embedded in the MS matrix aggregated, leading to magneto-dielectric effects such as the enhancement of the complex dielectric permittivity components when applying the magnetic field as a principal effect and the enhancement of the electric capacitance and time constant of the capacitors as a secondary effect. The obtained results represent landmarks in the realization of low-cost magnetic field sensors, deformation and mechanical stress transducers in the robotics industry, etc. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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22 pages, 4222 KiB

Open AccessArticle

Study on the Aging Mechanism and Microstructure Analysis of Rice-Husk-Ash- and Crumb-Rubber-Powder-Modified Asphalt

by Yiming Li, Alaaeldin A. A. Abdelmagid, Yanjun Qiu, Enhui Yang and Yanjun Chen

Polymers 2022, 14(10), 1969; https://doi.org/10.3390/polym14101969 - 12 May 2022

Cited by 6 | Viewed by 2240

Abstract

In this paper, the rice husk ash and crumb rubber powder were used as a combined modifier for asphalt. The impact of the aging on the physical and rheological properties of crumb rubber powder, rice husk ash, and the combined modified asphalt was [...] Read more.

In this paper, the rice husk ash and crumb rubber powder were used as a combined modifier for asphalt. The impact of the aging on the physical and rheological properties of crumb rubber powder, rice husk ash, and the combined modified asphalt was studied through the rolling thin film oven (RTFO) simulations. A Fourier-transform infrared Spectroscopy (FTIR) test was used to study the aging mechanisms of the combined crumb-rubber-powder- and rice-husk-ash-modified asphalt before and after aging through the changes in functional groups. Impacts of the combined, crumb rubber powder, and rice husk ash modifiers on the anti-aging characteristic of the asphalt binder were analyzed through different aging indices and the variations in intensity of the absorption peaks. According to the combined results, the addition of the combined crumb rubber powder, and rice husk ash could enhance the thermal oxidative aging resistance binder. Moreover, the optimal content of composite modified asphalt was (7% rice husk ash + 10% crumb rubber powder). In addition, the combined modified asphalt binder had all the peaks of neat asphalt, rice-husk-ash-modified asphalt, and crumb-rubber-powder-modified asphalt and no appearance of new peaks. A scanning electron microscope (SEM) test was carried out to observe the microstructure of the combined crumb-rubber-powder- and rice-husk-ash-modified asphalt binders. The obtained result demonstrated that different SEM images showed that the combined crumb rubber powder, and rice husk ash modifiers were uniformly dispersed inside the asphalt binder and consequently leading to format a homogeneous blended binder. Full article

(This article belongs to the Topic Rubbers and Elastomers Materials)

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