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In the present work, biophenol and furfural‐based resol resin was synthesized and utilized for the very first time to cure styrene butadiene rubber (SBR). The reaction was studied over a range of times, temperatures, pH, and furfural to biophenol ratios to fix the optimum conditions. Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy revealed the functional groups and chemical structure of the synthesized resin, respectively. An exothermic peak for the resin curing appeared at 143°C in the differential scanning calorimetry thermogram of the resin. Then, the biophenol‐furfural resin was utilized for the curing of SBR. The synthesized resin increased the tensile strength of the raw rubber from 0.20 ± 0.01 MPa to 1.22 ± 0.10 MPa at 10 phr loading, and the crosslink density was 2.56 × 10−5 mol/mL. The activation energy for curing SBR containing 10 phr resin was 97 kJ/mol. The storage modulus of the resin‐cured compound was improved. The glass transition temperature of the raw SBR was also shifted from −43.8 to −42.3°C when 10 phr resin was used for the curing. Hence, for the first time, this work reported the utilization of biophenol‐biosourced furfural resin to cure rubbers. [ABSTRACT FROM AUTHOR]

This work develops a probability-based numerical method for quantifying mechanical properties of non-Gaussian chains subject to uniaxial deformation, with the intention of being able to incorporate polymer–polymer and polymer–filler interactions. The numerical method arises from a probabilistic approach for evaluating the elastic free energy change of chain end-to-end vectors under deformation. The elastic free energy change, force, and stress computed by applying the numerical method to uniaxial deformation of an ensemble of Gaussian chains were in excellent agreement with analytical solutions that were obtained with a Gaussian chain model. Next, the method was applied to configurations of cis- and trans-1,4-polybutadiene chains of various molecular weights that were generated under unperturbed conditions over a range of temperatures with a Rotational Isomeric State (RIS) approach in previous work (Polymer 2015, 62, 129–138). Forces and stresses increased with deformation, and further dependences on chain molecular weight and temperature were confirmed. Compression forces normal to the imposed deformation were much larger than tension forces on chains. Smaller molecular weight chains represent the equivalent of a much more tightly cross-linked network, resulting in greater moduli than larger chains. Young's moduli computed from the coarse-grained numerical model were in good agreement with experimental results. [ABSTRACT FROM AUTHOR]

The present work is focused on finding (i) the tearing energy at rupture and (ii) the redistribution of incorporated paraffin oil on the ruptured surfaces as functions of (a) the initial oil concentration and (b) the speed of deformation to the total rupture in a uniaxially induced deformation to rupture on an initially homogeneously oil incorporated styrene butadiene rubber (SBR) matrix. The aim is to understand the deforming speed of the rupture by calculating the concentration of the redistributed oil after rupture using infrared (IR) spectroscopy in an advanced continuation of a previously published work. The redistribution of the oil after tensile rupture for samples that have three different initial oil concentrations with a control sample that has no initial oil has been studied at three defined deformation speeds of rupture along with a cryo-ruptured sample. Single-edge notched tensile (SENT) specimens were used in the study. Parametric fittings of data at different deformation speeds were used to relate the concentration of the initial oil against the concentration of the redistributed oil. The novelty of this work is in the use of a simple IR spectroscopic method to reconstruct a fractographic process to rupture in relation to the speed of the deformation to rupture. [ABSTRACT FROM AUTHOR]

In this work, a synthetic technique was developed which effected delamination of graphite into graphene with simultaneous disaggregation of carbon black clusters and formation of secondary attachment between the two. Styrene butadiene rubber nanocomposite with this hybrid filler exhibited substantial reinforcement in the mechanical properties, wear resistance and rubber‐filler interactions. The hybrid nanofiller was superior to conventional carbon black, imparting 57% increase in tensile strength of the nanocomposite. The composite with the hybrid filler also exhibited improved modulus and traction. A detailed analysis of mechanism of reinforcement by the hybrid filler is proposed by the computation of root mean square end‐to‐end network chain distance and the lateral tube dimension employing the entangled‐bound‐rubber‐tube (EBT) model. This neoteric hybrid nanofiller overcame the so‐called dispersibility issues and could be exploited as a part of replacement of carbon black, a synthetic material from fossil fuel by sustainable natural filler. [ABSTRACT FROM AUTHOR]

Facing microplastic contamination and thereby its impacts on the environment and health will probably be one of the most concerning challenges in our immediate future. Yet, data on these emerging pollutants are still scarce in many aspects leading to the ongoing development and expansion of analytical procedures and approaches. In recent years, despite being used formerly only for qualitative aspects, nuclear magnetic resonance spectroscopy (NMR) was introduced for the quantification of microplastic particles. By the combination of linear regression procedures, internal standards and the integration of proton NMR, the so-called qNMR method allows mass-based quantification of microplastics in a limited amount of time and independent of particle size. Based on this approach, further optimization through the simultaneous dissolution and quantification of multiple polymers is investigated. Individual requirements, known issues and considerations will be demonstrated along with additional possibilities for five polymers: polystyrene (PS), butadiene rubber (BR), polyvinylchloride (PVC), polyethylene terephthalate (PET) and polyamide (PA). The applicability of homopolymer-based calibrations is demonstrated for both the quantification of multiple homopolymers dissolved in a shared solvent system and the quantification of copolymers; for example, a styrene–butadiene copolymer (SBR). Linearities and limits of detection and quantification as well as precision and accuracy comparable to those of solely measured microplastic particles are achieved. The improvement significantly reduces the preparation and measurement time in combination with lowered costs. In addition, enhanced reliability was achieved by implementing hexamethyldisiloxane (HMDSO) as an internal standard in NoD measurements, replacing dichloromethane (DCM). [ABSTRACT FROM AUTHOR]

To improve the uniformity and the mechanical/wear performances of the aramid pulp (AP)/nitrile butadiene rubber (NBR) composites, two types of ionic liquids (ILs), that is, 1‐carboxymethyl‐3‐methylimidazolium chloride ([CmMIM]Cl) and 1‐allyl‐3‐vinylimidazolium chloride ([AVIM]Cl) were applied on the AP surface, respectively. The ILs partially disrupted the hydrogen‐bonds between the aramid chains to mitigate the fiber entanglement, and connected the AP to the rubber matrix by hydrogen‐bond interaction or the crosslinking reaction during the vulcanization. The test results showed that, the IL treatments effectively improved the tensile and tear strengths without obviously affecting the physical characteristics of the composites. The wear properties of the AP/NBR composites also improved due to the enhancements of the tear strength and the connection between the AP and NBR matrix. Compared to the [CmMIM]Cl, the [AVIM]Cl was more efficient to improve the properties attributed to its better compatibilization for the AP/NBR system. For example, the specific wear rate under 20‐N load of the composite with 15‐phr [AVIM]Cl‐AP was 1.1 × 10−7 mm3 N−1 mm−1, which was approximately 25% and 35% lower than that of the composites reinforced with 15‐phr [CmMIM]Cl‐AP and untreated AP, respectively. [ABSTRACT FROM AUTHOR]

The effects of N‐isopropyl‐N′‐phenyl‐phenylenediamine (4010NA) content on the damping and aging properties of hydrogenated nitrile butadiene rubber (HNBR)/nitrile butadiene rubber (NBR) (abbreviated as H‐NBR) matrix are studied via molecular simulation and experiments. The effects of 4010NA addition on the damping and aging properties of H‐NBR are analyzed by molecular simulation using solubility parameters (δ), hydrogen bonds, free volume fraction (FFV), binding energy (Ebinding), hydrogen bond dissociation energy (ΔG), and mean square displacement (MSD). The damping, mechanical, and thermo‐oxygen aging properties of the 4010NA/H‐NBR composites are studied experimentally using infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The results indicate that 4010NA has good compatibility with HNBR and NBR, and the addition of 4010NA can effectively improve the damping properties of H‐NBR. When 4010NA is added at 32 phr, the composite has better damping properties, mechanical properties, and aging resistance, which provides a new insight for the construction of high performance elastomer composites. [ABSTRACT FROM AUTHOR]

The study of the reinforcement network in elastomer compounds is one of the most relevant issues for the application of these materials because their properties are strongly dependent on the obtained morphology. To this regard, the viscoelastic and dielectric behavior of vulcanized styrene butadiene rubber (SBR) reinforced with different amounts of carbon nanotubes (CNT) have been investigated and compared with the vulcanized unfilled SBR and the vulcanized SBR samples reinforced with a conventional amount of carbon black (40 phr). Differential scanning calorimetry (DSC) measurements have been carried out to highlight possible differences of the glass transition temperatures for all the reinforced compounds. The percolation threshold value of the nanocomposite samples has been estimated by dielectric analysis. Finally, dynamic mechanical analysis (DMA) measurements have been performed in tensile mode in the temperature range of −60 to 80 °C to obtain both E′ and E′′. From these experimental data, the master curve for each sample has been estimated by using the time–temperature superposition principle in combination with the vertical shift approach. From the analysis of this latter, the activation energy, associated to the thermal movement of the reinforcement network, has been calculated to better elucidate the reinforcement mechanism in the nanocomposites. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of novel amine terminated polybutadiene, polyurea and TiO2-nanocomposites is the aim of current art work. In this regard, polyurea synthesized trough following consecutive reactions: 1. Oxidative chains scission of polybutadiene (PB) by meta-chloroperbenzoic acid (m-CPBA) and periodic acid (H5IO6) to prepare telechelic aldehyde functionalized polybutadiene, 2. Terminal amine functionalized polybutadiene synthesis via reductive amination reaction of prepared aldehyde functionalized polybutadiene and ethylenediamine (EDA) by sodium borohydride (NaBH4) and finally, 3. Telechelic polyurea preparation through the reaction of synthesized amine functionalized polybutadiene and toluene diisocyanate (TDI). A one-pot polymerization procedure was employed to synthesize nanocomposites by the incorporation of 1 to 3% of surface modified TiO2 nanoparticles by amino propyl triethoxy silane (APTS). Successful synthesize of amine functionalized polybutadiene, polyurea and nanocomposites investigated using 1H-NMR and FT-IR spectroscopy techniques. TGA/DTG and DSC methods proved successful surface modification of nanoparticles, improved thermal stabilities with lower degradation rates and superior thermal characteristics especially in 3 wt% nanocomposite when compared by pristine sample. SEM, XRD and AFM analysis confirmed successful nanocomposite synthesis with progressed morphologic and topographic properties. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry 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.)

The study focused on the hydrophobization of cotton textiles. Polybutadienes substituted by alkoxysilyl groups were used to modify cotton fabric. Compounds were obtained via thiol-ene click reactions. Cotton textiles were modified through a dip-coating process. The influence of the amount of the functional group on a polybutadiene chain was investigated. Moreover, the influence of the spacer length between the polybutadiene hydrocarbon chain and alkoxysilyl groups on the hydrophobic effect of modified fabrics was also investigated. Hydrophobicity was assessed by measuring the water contact angle (WCA) and capacity of absorption of a water drop. Moreover, in order to confirm the modification of cotton surface, Fourier-transform infrared spectroscopy (FT-IR), elemental analysis using Scanning Electron Microscopy–Energy Dispersive Spectroscopy (SEM–EDS), and SEM analyzes were performed. The obtained results showed that all performed modifications gave a strongly hydrophobic effect on the textile surface. In the best method superhydrophobicity was achieved. Moreover, the performed research confirmed the durability of investigated modification for multiple washing processes as a result of the presence of alkoxysilyl groups in polybutadienes. [ABSTRACT FROM AUTHOR]

The safety of solid rocket engine use seriously affects the survivability and combat effectiveness of weaponries. To study the engine safety against fragment in complex battlefield environments, the fragment impact safety simulation study of a high-energy four-component HTPB propellant solid engine (hereafter referred to as high-energy HTPB propellant engine) was conducted. The equation of state parameters and reaction rate equation parameters of the detonation product of high-energy HTPB propellant were calibrated by using a 50 mm diameter cylinder test and Lagrange test combined with genetic algorithm. The nonlinear dynamics software LS-DYNA was used to build a finite element model of the fragment impact engine and simulate the mechanical response of the high-energy HTPB propellant under different operating conditions. This study shows that the critical detonation velocity decreases with the increase of the number of fragments. When the number of fragments is more than 5, the influence of this factor on the critical detonation velocity is no longer obvious. Under the same loading strength conditions, the greater the metal shell strength and the greater the shell wall thickness, the more difficult it is for the high-energy HTPB propellant to be detonated by the shock. This study can provide a reference for the design and optimization analysis of solid rocket engine fragment impact safety. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS 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.)

Hydroxyl-terminated polybutadiene (HTPB)-based piezoelectric polymer (m-HTPB) is prepared for the first time by functionalized branch chain modification strategy. In the presence of HTPB with >98.8% cis-1,4 content, the C=C bond partly breaks down, and functionalized acetylferrocene groups are introduced to the cis-1,4 polybutadiene branch chain, retaining the high cis-1,4 content of HTPB. The whole process is conducted under mild conditions, without complicated manipulations. The microstructure and molecular weight of m-HTPB are characterized by Fourier-transform infrared (FTIR) spectra, 1H or 13C nuclear magnetic resonance spectrum (NMR), and gel permeation chromatography (GPC). The thermal properties of HTPB and m-HTPB are determined by differential scanning calorimetry (DSC). Electrochemical investigations reveal that m-HTPB exhibits higher conductance compared with HTPB. The m-HTPB flexible piezoelectric polymer is further used for in situ and real-time pressure monitoring. This simple and effective strategy provides a promising polymeric material for flexible piezoelectric sensors. [ABSTRACT FROM AUTHOR]

Spent Fluid Catalytic Cracking (FCC) Catalyst is a major waste in the field of the petroleum processing field, with a large output and serious pollution. The treatment cost of these waste catalysts is high, and how to achieve their efficient reuse has become a key topic of research at home and abroad. To this end, this paper conducted a mechanistic and experimental study on the replacement of some carbon blacks by spent FCC catalysts for the preparation of rubber products and explored the synergistic reinforcing effect of spent catalysts and carbon blacks, in order to extend the reuse methods of spent catalysts and reduce the pollution caused by them to the environment. The experimental results demonstrated that the filler dispersion and distribution in the compound are more uniform after replacing the carbon black with modified spent FCC catalysts. The crosslinking density of rubber increases, the Payne effect is decreased, and the dynamic mechanical properties and aging resistance are improved. When the number of replacement parts reached 15, the comprehensive performance of the rubber composites remained the same as that of the control group. In this paper, the spent FCC catalysts modified by the physical method instead of the carbon-black-filled SBR can not only improve the performance of rubber products, but also can provide basic technical and theoretical support to realize the recycling of spent FCC catalysts and reduce the environmental pressure. The feasibility of preparing rubber composites by spent catalysts is also verified. [ABSTRACT FROM AUTHOR]

This paper discusses the influence of partitioning of carbon black (CB) with its increasing concentration (i.e., 10, 20, 30, 40, and 50 phr) on physical and static mechanical properties of Styrene Butadiene Rubber (SBR)/Butadiene Rubber (BR) rubber–rubber blends (RRB's) in 70SBR:30BR blend ratio. Partitioning of CB towards BR in CB‐filled SBR/BR RRB's is quantitatively determined via dynamic mechanical analysis (DMA). DMA confirmed increased partitioning of CB towards BR phase with increasing CB. DMA data on the partitioning of CB towards BR were in good agreement with nuclear magnetic spectra obtained by solid‐state nuclear magnetic resonance spectroscopy (SS‐NMR spectroscopy). Curing properties, relative density, hardness, tensile test, tear test, and transmission electron microscopy (TEM) on CB filled SBR/BR RRB's were carried out to determine the effect of increasing concentration of CB on physical, mechanical, and dispersion characteristics in comparison to neat SBR/BR RRB's. [ABSTRACT FROM AUTHOR]

In order to improve the adaptability of sweet cherry sorters to sweet cherries, a full-view-type grading cup for automated sweet cherry sorters was developed based on the physical characteristics of three species of sweet cherries: Tieton, Huang Mi, and Lapins. The structure and working principle of the full-view-type grading cup are described in this paper. The main factors affecting the operating stability of the grading cup were identified in this study by analyzing the mechanical properties of sweet cherries during the conveying and rotating process. According to the Box-Behnken test design method, we took the operating speed, the Young's modulus, and the friction coefficient of the double-roller supporter as the test factors and we took the success rate as the test index. The operating parameters of the full-view-type grading cup were tested and studied, and the regression model between the test index and the test factors was established. The influence law of each factor on the test index was analyzed, and the test factors were comprehensively optimized according to the regression model. The results showed that when the operating speed was 48 sweet cherries/min; the butadiene rubber (BR) 9000, with a Young's modulus of 0.012 GPa was selected as the material for making the double-support rollers; and the friction coefficient was designed to be 15, the success rate was 86.0%. The results of this research have provided a theoretical basis for the design and optimization of grading cups for automated sweet cherry sorters. [ABSTRACT FROM AUTHOR]

This paper presents the influence of zinc on the cross-linking process, mechanical and dynamic properties, morphologies and balance of thermal degradation of blends containing chloroprene rubber (CR) and butadiene rubber (BR). The novel aspect of this research is a comprehensive approach presenting a new curing agent for the CR/BR blends to increase their cross-linking density and final properties, including non-flammability and low fire hazard. This is due to the need to find an alternative to zinc oxide, which is the standard curing agent for chloroprene rubber. The regulations of the European Union enforce a significant limitation on the use of this compound in elastomer technology, due to its harmful effect on aquatic organisms. In this paper, the CR/BR composites were cured with zinc and filled with natural silica fillers (sillitin or chalcedonite) or synthetic silica filler (aerosil). The investigation focused on the morphology characterization of the obtained compounds, their cross-linking degree, swelling, mechanical and dynamic properties, fire hazard and toxicity. The structure of cured CR/BR blends was characterized via scanning electron microscopy (SEM). The fire resistance studies were performed using cone calorimetry or oxygen index methods, whereas toxicity tests were performed with the use of the FB-FTIR (fluidized bed reactor coupled with FTIR analyzer) method. The results showed that obtained CR/BR products were characterized by satisfactory final properties. The properties determined by the oxygen index and cone calorimetry methods, including the behaviors of the tested CR/BR vulcanizates in fire conditions, showed that the produced compounds were characterized by a low fire hazard and can be classified as non-combustible rubber products. However, the toxicity of the decomposition products, determined at 450, 550 and 750 °C, was very high. [ABSTRACT FROM AUTHOR]

Replacement of virgin polymer with its waste become one of the special technique that capture the efforts of many researchers and industrialists alike. In this context, this work discussed the partial replacement of waste tire rubber (WR) and microwave devulcanized rubber (DWR) at different ratios on the properties of virgin styrene butadiene rubber (SBR) as one of the most essential components of synthetic rubber in the tire production. Fixed percent of tetramethylthiuram disulfide and spindle oil were added at the first, then the WR mixture was exposed to different microwave times. Microwave devulcanization value at time 6 min gave the highest devulcanization percent. The prepared blends were exposed in an electron beam accelerator (EB) at 50 and 100 kGy. FTIR, different mechanical parameters, thermal stability (TGA) and scanning electron microscopy of the fabricated specimens have been explained. Effect of automotive oil and thermal aging at different temperature, 70oC and 100oC on the tensile strength and elongation at break (E%) of the unirradiated and irradiated prepared blends have been estimated. Mechanical measurements of all examined specimens after thermal aging and oil immersion were least affected. Moreover, these factors before and after oil dipping and thermal aging revealed that unirradiated and irradiated SBR/DWR blends have superior properties than SBR/WR. Graphical Abstract [ABSTRACT FROM AUTHOR]

The occurrence and characterization of marine debris on beaches bring opportunities to track back the anthropogenic activities around shorelines as well as aid in waste management and control. In this study, the three largest beaches in Thanh Hoa (Vietnam) were examined for plastic waste, including macroplastics (≥ 5 mm) on sandy beaches and microplastics (MPs) (< 5 mm) in surface water. Among 3803 items collected on the beaches, plastic waste accounted for more than 98%. The majority of the plastic wastes found on these beaches were derived from fishing boats and food preservation foam packaging. The FT-IR data indicated that the macroplastics comprised 77% polystyrene, 17% polypropylene, and 6% high-density polyethylene, while MPs discovered in surface water included other forms of plastics such as polyethylene- acrylate, styrene/butadiene rubber gasket, ethylene/propylene copolymer, and zein purified. FT-IR data demonstrated that MPs might also be originated from automobile tire wear, the air, and skincare products, besides being degraded from macroplastics. The highest abundance of MPs was 44.1 items/m3 at Hai Tien beach, while the lowest was 15.5 items/m3 at Sam Son beach. The results showed that fragment form was the most frequent MP shape, accounting for 61.4 ± 14.3% of total MPs. MPs with a diameter smaller than 500 μm accounted for 70.2 ± 7.6% of all MPs. According to our research, MPs were transformed, transported, and accumulated due to anthropogenic activities and environmental processes. This study provided a comprehensive knowledge of plastic waste, essential in devising long-term development strategies in these locations. [ABSTRACT FROM AUTHOR]

The tackifying effect of resins used in the tire industry highly depends on the compatibility and interaction strength with the rubber matrix. Here, uncured and cured styrene/butadiene rubber compounds, either in the presence or absence of a hydrocarbon aromatic tackifying resin, were studied by means of high-resolution and time-domain solid-state NMR (SSNMR) techniques to investigate resin/polymer interactions and the effect of the resin on the dynamics of polymer chains. 13C direct excitation and cross-polarization spectra, combined with low-field measurements of 1H T1 and analysis of 1H on-resonance free-induction decay, provided information on the dynamic heterogeneity of the samples and the degree of mixing between the resin and the rubber matrix. Moreover, 1H T1 and T1ρ relaxation times at variable temperatures were used to investigate the effect of resin on both segmental dynamics activated at the glass transition and collective polymer dynamics. SSNMR findings were discussed in relation to crosslink density and Tg data. The obtained results show that the resin is intimately mixed with the polymer, while maintaining its rigid character. A slowdown of segmental dynamics, related to an increase in Tg, was found as a consequence of resin addition, while no effect was evidenced on fragility and collective polymer dynamics. [ABSTRACT FROM AUTHOR]

Vulcanization is an important step in the manufacture of solid tires in which the crosslinking process occurs. In vulcanization, the materials commonly used as activators and coactivators are ZnO and stearic acid, respectively. In this research, ZnO and stearic acid were replaced with zinc stearate to improve the characteristics of vulcanized rubber. Zinc stearate was applied in four formulas with a composition of 5 to 9 phr. A formula that is often used in the rubber industry was used as a comparison, and ZnO and stearic acid of 5 phr and 2.5 phr, respectively, were applied. The rubber compound for solid tire production was developed using an open mill at a compounding temperature of 45 °C ± 5 °C. The vulcanization process of developing the rubber compound into vulcanized rubber was carried out at 150 °C for 20 min. Rubber compound test results showed that the use of zinc stearate at a ratio of 8 phr accelerated the curing time (t90) between 58.3% and 69%, the scorch time (ts2) between 22.4% and 95.5%, and the torque delta (Δs) between 17.67 and 24.21 kg-cm. In addition, the vulcanized rubber mechanical properties test results for the compression set parameter increased between 28.6% and 57.1%. Scan results with SEM–EDS showed that using ZS could improve the homogeneous distribution of the material in the vulcanized matrix of solid tire rubber. [ABSTRACT FROM AUTHOR]

Polybutadiene‐based (PB) composite substrates filled with TiO2 and SiO2 ceramics were fabricated in this work. The total content of ceramic components modified by vinyltrimethoxysilane (A171) was fixed at 80 wt.% with TiO2 amount varying from zero to 8 wt.%. The differences of characteristics of ceramic fillers before and after surface modification were analyzed comprehensively and the treated ceramic fillers were uniformly distributed in the polymer matrix. The effects of TiO2 filler addition on the performances of SiO2/PB composite substrates, such as microstructure, moisture absorption, dielectric and thermal properties were also systematically studied. The composite filled with 4 wt.% TiO2 and 76 wt.% SiO2 exhibited excellent dielectric properties with proper dielectric constant (ϵr=3.2), ultra‐low dielectric loss (tanδ=0.0017) at 10 GHz and a near‐zero τϵ (0.5 ppm/°C) was obtained at filler content of 8 wt.% TiO2 and 72 wt.% SiO2. [ABSTRACT FROM AUTHOR]

The jute/polylactic acid (PLA) composite material has been widely concerned in the field of composite materials because of its green, degradable and renewable properties, but its low mechanical properties limit the application field. In order to improve the mechanical properties of jute/PLA composites, styrene butadiene rubber (SBR) particles modified by different silane coupling agents were introduced into PLA matrix, and jute/PLA composites were prepared by solution casting and molding method. The changes in the mechanical properties of the jute/PLA composite were studied, and the toughening mechanism of the jute/PLA composite was analyzed. The results show that SBR particles can induce the crystallization of the PLA matrix, and the coupling agent plays a promoting role. The addition of SBR improves the bending and stretching of the jute/PLA composite. The silane coupling agent KH560 has the best modification effect on SBR particles. When the mass fraction of KH560-SBR particles in the composite is 1.0%, its bending strength and modulus achieve the highest, which are respectively 247.04% and 773.91% higher than the control group. When the mass fraction of KH560- SBR particles added in the composite is 2.0%, its tensile strength and modulus are the largest, 517.91% and 472.00% higher than the control group. [ABSTRACT FROM AUTHOR]

The current work presents the study of a semicrystalline, shape memory polymer synthesized by simultaneous free radical polymerization and crosslinking in a blend of polybutadiene (PB) and octadecyl acrylate. Blending elastomers and phase change materials provide a modular method for new smart materials, such as shape memory polymers. In this system, grafted, side‐chain crystalline poly(octadecyl acrylate) (PODA) fixes a programmed shape in the shape memory cycle, while crosslinked polybutadiene drives shape recovery. This work focuses on improving material parameters important for shape memory (crystallinity, gel fraction, melting temperature) by tuning the processing and formulation parameters (amount of crosslinker and PB weight fraction). The result is a shape memory PB‐PODA copolymer that can be fabricated by melt processing and programmed without cooling below ambient temperature. It is found that good shape memory (i.e., high shape fixity and recovery) is obtained at a low PB weight fraction where a percolating PODA crystal network is formed at room temperature. The optimized sample shows excellent shape memory properties (fixity > 99%, recovery = 96%). It is shown that it is possible to mold this material into complex 3D shapes or topography with potential use in anticounterfeiting and antitampering applications. [ABSTRACT FROM AUTHOR]

Asphalt is a typical viscoelastic material and its rheological behavior is highly dependent on temperature and loading time (or frequency). The equivalent relationship between temperature dependency and frequency dependency can be utilized to perform the conversion between temperature domain and frequency domain. The aims of this research are to highlight the importance of this domain transformation and then detail a method of transforming asphalt rheological properties from frequency domain to temperature domain based on Williams-Landel-Ferry (WLF) equation. Frequency sweep and temperature sweep tests were conducted on three types of asphalt binders including one pure asphalt and two modified asphalt binders (styrene butadiene rubber (SBR) modified asphalt (SBRMA) and styrene-butadiene-styrene (SBS) triblocks copolymer modified asphalt (SBSMA)). Master curves were constructed based on time-temperature superposition principle (TTSP) and the WLF equations were solved as well. Thereafter, asphalt rheological properties were transformed from frequency domain to temperature domain based on WLF equation. The suitability and the accuracy of introduced transformation method were evaluated in terms of different asphalt binders and rheological indexes. The results indicate that with the help of transformation method based on WLF equation, the temperature domain of rheological properties can be broadened by frequency domain compensation. Additionally, the isochrones of complex modulus derived from domain transformation can be generally consistent with isochrones obtained from temperature sweep tests, although some deviations appear at higher temperatures (more than 60 °C). And the phase angle can be more suitable for domain transformation from frequency to temperature than complex modulus. [ABSTRACT FROM AUTHOR]

Using bisphenol A (BPA) and isophthalaldehyde (IPD) as comonomers, based on open system and solution polycondensation method, phenolic resin was prepared by microwave. The reversible thermochromic composite solution polymerized butadiene styrene rubber film was prepared by resin as chromogenic agent. The resin was tested by gel permeation chromatography, 1H and 13C NMR spectrometers, thermogravimetric analyzer, and thermal analyzer, etc. The composite film was tested by thermogravimetric analyzer, thermal analyzer, spectrophotometer, and polarizing microscope, etc. The factors affecting the thermochromic properties, thermal stability, thermal recyclability stability and microscopic morphology of the composite film were studied. The results indicate that BPA-IPD is the 2,6-monosubstituted bisphenol A isophthalaldehyde phenolic resin with M–n of 1.150 × 103 g mol–1 and PDI of 1.004. Therefore, the number of monomers in molecular chain containing BPA and IPD are 3 and 3, respectively. When the mass ratio of crystal violet lactone, resin, mixed alcohols (cetyl alcohol and octadecanol) and solution polymerized butadiene styrene rubber is 1 : 1.5 : 30 : 50, i.e., 0.0075 : 0.011 : 0.23(0.14 : 0.09) : 0.38(g), the composite film is obtained by salivation method. The total color difference (ΔE) of composite film is about 90, and its absorption/scattering color depth difference [Δ(K/S)] values are averagely 20 and 40 at visible light zone of 480– 600 and 600–660 nm at the low temperature region (10–33°С) of phase change during constant speed cooling, respectively. The composite film has good thermal stability and recyclability stability. [ABSTRACT FROM AUTHOR]

The study assessed the coagulating ability of copolymers N,N-diallyl-N,N-dimethylammonium chloride with acrylamide and maleic acid when separating styrene/butadiene and nitrile/butadiene rubbers from latexes. The effect of the consumption of these cationic polymers, the concentration of the dispersed phase and temperature on the completeness of rubber separation was studied. It was established that the completeness of styrene/butadiene rubber separation from latex is achieved at a 0.5 kg t–1 consumption of cationic copolymer with acrylamide, and that of butadiene/nitrile rubber is achieved at 22 kg t–1. The introduction of maleic acid units into the cationic copolymer ensures the complete separation of styrene/butadiene and nitrile/butadiene rubber from latex at a consumption of 0.3 and 8 kg t–1, respectively. Vulcanizates obtained from rubbers isolated using copolymers meet the requirements of State Standard GOST 15627–2019. [ABSTRACT FROM AUTHOR]

The identification of accelerant about gasoline and other ignited liquids in arson has always been a difficult problem in the field of physical evidence identification. How to avoid “false positive” and “false negative” results is a key issue. To study the interference of diene rubber on gasoline identification from two aspects of “false positives” and “false negatives”, and to explore its degree when gasoline was mixed with diene rubber in different proportions, the combustion residues obtained from cis-polybutadiene rubber, isobutylene isoprene rubber and styrene butadiene rubber after loading different amounts of gasoline were compared using gas chromatography-mass spectrometry (GC-MS). The results showed that alkanes, alkenes/cycloalkanes, aromatic-alkylbenzenes, homologs of indenes and indanes, alkylnaphthalenes and polycyclic aromatic hydrocarbons were detected in the combustion residues of the three kinds of diene rubber samples before and after gasoline loading, which was consistent with gasoline in terms of the characteristic components categories and had strong interference with gasoline identification. After loading 0.05 mL and 0.1 mL gasoline respectively into 5 g rubber sample, there was no significant changes in the characteristic components of cycloalkanes/alkenes, alkylnaphthalenes, and polycyclic aromatic hydrocarbons in the rubber combustion residues. The number and relative peak area ratio of characteristic peaks corresponding to aromatic-alkylbenzenes, homologs of indenes and indanes changed to different degrees, while the changes of alkylbenzenes were more representative. Loading gasoline or not had little effect on the ratio of the characteristic peaks of C2 benzene components in the combustion residues of cis-polybutadiene rubber. The ratio among three characteristic peaks of C2 benzene components in the combustion residues of isobutylene isoprene rubber and styrene butadiene rubber samples changed significantly when the gasoline loading amount reached 0.1 mL. This study can provide important references for the gasoline identification when there is a presence of diene rubber matrix in practical work. [ABSTRACT FROM AUTHOR]

Liquid trimethoxy silane-functionalized cis-polybutadiene (cis-PB-Si(OMe)3), possessing number-average molecular weights of cis-PB segments (Mn,PB) ranging from 1800 g/mol to 5400 g/mol, with cis-1,4 content of ca. 80% and high functionality (>96%) could be synthesized by coordination copolymerization of living cis-PB chain ends with ethenyltrimethoxy-silane with neodymium-based catalytic system. The silicon hydroxyl-functionalized cis-polybutadiene (cis-PB-Si(OH)3)-based micelles in water have been achieved by in situ hydrolysis of cis-PB-Si(OMe)3 in hexane/water mixture (pH=6.8) at 70 °C and by sequential removal of residue hexane. The size of the above micelles with soft elastic cis-PB cores could be remarkably enlarged by loading SiO2 nanoparticles on their surfaces via hydrogen bonding interaction. Giant supramolecular long chain aggregates or networks formed by hydrogen bonding interaction and possible O—Si—O chemical bonds between cis-PB-Si(OH)3-based micellar surfaces had relatively large size and thus precipitated from water after several months of storage, leading to production of cis-PB-Si(OH)3 solid elastomer with extremely low Tg at −107.0 °C. The left cis-PB-Si(OH)3-based micelles in water with relatively small size gradually formed the water-insoluble cis-PB-Si(OH)3-based supramolecular aggregates or networks. The cis-PB-Si(OH)3-based supramolecular elastomer exhibited excellent self-healing property within 60 s at 25 °C. The elastomer (20 mg) in a joint of 25 mm × 30 mm (2.7 mg/cm2) provided very strong adhesion for two pieces of glass and the bound glass keep unchanged at room temperature for 98 h even hung with 100 g of steel column below. The cis-PB-Si(OH)3-based supramolecular elastomer would have potential applications in adhesives, self-healing materials, damping materials and elastic materials. [ABSTRACT FROM AUTHOR]

Preparation of rubber nanocomposites using two or more nanofillers with different geometries is a new and promising approach. In this work, the effects of boron nitride nanosheets (BNNS), carbon nanotubes (CNT) and their hybrid (BNNS‐CNT) on the performances of styrene butadiene rubber (SBR) nanocomposites are systematically studied. The mechanical properties of the nanocomposites are significantly enhanced by the nanofillers. The tensile strength of unfilled SBR is only 1.30 ± 0.18 MPa, which increases to 1.72 ± 0.24 MPa (BNNS), 4.09 ± 0.35 MPa (CNT), and 3.37 ± 0.29 MPa (BNNS‐CNT) at 4 phr, respectively. Similarly, the tear strength of unfilled SBR is 8.0 kN/m, which increases to 13.8 kN/m (BNNS), 16.1 kN/m (CNT) and 18.2 kN/m (BNNS‐CNT) at 4 phr, respectively. Moreover, the thermal behavior of the nanocomposites are analyzed. Compared with single nanofiller BNNS or CNT, BNNS‐CNT hybrid nanofiller not only effectively improves the mechanical properties of nanocomposites, but also imparts better thermal properties. It is proved that the thermal decomposition temperature of SBR/4phr BNNS‐CNT is increased by nearly 7°C compared with unfilled SBR. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to evaluate the ability to predict the roughened surface area of soft polymeric materials using the machine learning method. Random forest and extremely random forest machine learning methods have been applied to predict roughened monolithic butadiene styrene rubber surface area based on the grain diameter of the abrasive paper. It was found that there is a very strong negative correlation between surface roughness and abrasive grain diameter (the Pearson correlation coefficient is equal to - 0.83 and the Spearman correlation coefficient is equal to - 0.91). The statistics of Shapiro-Wilk criteria confirmed that independently of the diameter of abrasive grain, the lengths of rubber surface profiles are normally distributed. It was determined that random forest and extremely random forest algorithms are suitable tools for predicting rubber surface area in dependence on abrasive grain diameter. The forest structure in which results obtained best coincidence with the observed (R2 = 0.95): for the random forest model the number of trees is equal to 20, the leaf size is equal to 4, at the subset of the feature (abrasive paper grain diameter) equal to 1. In the case of an extremely random forest, the number of trees is equal to 350, the size of the subset of the features is equal to 1, and the leaf size is 2. The experimental and generated results agree well. The relative approximation error does not exceed 0.079 %. [ABSTRACT FROM AUTHOR]

Tyre acts as a linkage between a vehicle and road. Out of many functions a tyre must perform in its service life, durability is one of them. In service, a tyre is exposed to all kinds of road hazards (sharp asperities, pot holes, nails, etc.) and this may cause cuts on different parts of a tyre, viz. tread, sidewall, etc. These cuts propagate during subsequent loading and tyre may fail on reaching a critical crack length. To ensure tyre durability, knowledge of fatigue crack propagation is essential. In a tyre, majorly Natural rubber (NR), Butadiene rubber (BR) and Styrene butadiene rubber (SBR) are used. In this work, fatigue crack growth (FCG) characteristics of these rubbers and their blends using a Tear & Fatigue Analyser (TFA, Coesfeld GmbH & Co. KG, Germany) are studied in detail. This study emphasized on capturing the influence of material composition (rubber, rubber blend and filler) and operational conditions (temperature, waveform and R ratio) on FCG resistance of tyre rubber compounds. It has been observed that rubber blends have shown superior FCG resistance over single rubber compounds up to a certain tearing energy level. The influence of filler on FCG resistance has varied effect on crystallized and non-crystallized rubbers. In addition to filler, much higher property enhancement is observed in non-crystallized rubber compared to crystallized one. FCG resistance found to be increased with decrease in carbon black particle size. Temperature has a deleterious effect on FCG resistance and this effect is more prominent in blend compounds. Gaussian pulse load form exhibited higher FCG rate compared to sine loading. Positive R ratio exhibited superior FCG resistance, especially in NR compound. It has also been observed that advantage of positive R ratio effect in terms of superior FCG resistance diminished due to increase in measurement temperature. Fractured surface micrographs of NR compounds are distinctly different from BR and SBR compounds and reflected as higher root mean square roughness parameter. [ABSTRACT FROM AUTHOR]

As a typical viscoelastic material, solid propellants have a large difference in mechanical properties under static and dynamic loading. This variability is manifested in the difference in values of the relaxation modulus and dynamic modulus, which serve as the entry point for studying the dynamic and static mechanical properties of propellants. The relaxation modulus and dynamic modulus have a clear integral relationship in theory, but their consistency in engineering practice has never been verified. In this paper, by introducing the "catch-up factor λ" and "waiting factor γ", a method for the inter-conversion of the dynamic storage modulus and relaxation modulus of HTPB propellant is established, and the consistency between them is verified. The results show that the time region of the calculated conversion values of the relaxation modulus obtained by this method covers 10−8–104 s, spanning twelve orders of magnitude. Compared to that of the relaxation modulus (10−4–104 s, spanning eight orders of magnitude), an expansion of four orders of magnitude is achieved. This enhances the expression ability of the relaxation modulus on the mechanical properties of the propellant. Furthermore, when the conversion method is applied to the dynamic–static modulus conversion of the other two HTPB propellants, the results show that the correlation coefficient between the calculated and measured conversion values is R2 > 0.933. This proves the applicability of this method to the dynamic–static modulus conversion of other types of HTPB propellants. It was also found that λ and γ have the same universal optimal value for different HTPB propellants. As a bridge for static and dynamic modulus conversion, this method greatly expands the expression ability of the relaxation modulus and dynamic storage modulus on the mechanical properties of the HTPB propellant, which is of great significance in the research into the mechanical properties of the propellant. [ABSTRACT FROM AUTHOR]

A comparative study has been done to investigate the effect of carbon black (CB) and fumed silica (Si) on the physico-mechanical and thermal properties of Bagasse/styrene-butadiene rubber (B-SBR) composites. Based on the incorporation of 25 phr from natural ground bagasse powder (GBP) as a supplement reinforcing filler in styrene butadiene rubber (SBR) vulcanizates, two identical sets of formulations have been prepared using different concentrations (20, 40, 60 and 80 phr) of carbon black and silica as the main reinforcing fillers in SBR composites. The ground bagasse powder (GBP) employed in this work, has a selective grain size distribution ranging from about 20–180 μm. As well, 2.5 phr of maleic anhydride (MA) was incorporated to improve the interfacial adhesion between SBR and bagasse. The distinguishing effect of different fillers on the rheological properties was clearly established. Tensile strength, elongation at break, modulus at 100% elongation (M 100), hardness (Shore A), abrasion loss, degree of swelling, as well as, thermal gravimetric analysis (TGA) of the rubber vulcanizates were studied. The prepared samples were morphologically analysed by scanning electron microscopy (SEM). The tensile strength and M 100% values of carbon black-filled compounds were obviously higher than those of the silica filled ones. In addition, hardness, wear and swelling properties were improved more and more by increasing the filler content. Whereas, the Si filled B/SBR showed a decreasing trend in elongation at break values but with an evidently higher plateau than that of CB filled ones. Overall, the CB filled vulcanizates recorded dominant mechanical properties compared to the Si filled vucanizates. On the other hand, both fillers offered a noticeable improvement in thermal stability, but with a preference favored for the silica filled compounds. Furthermore, the findings for SEM were found to be in agreement with the observed mechanical properties. This study summarizes a detailed discussion of the emerging green technologies for tyre production and depicted comprehensive data from the available literature. [ABSTRACT FROM AUTHOR]

Hydroxyl-terminated polybutadiene (HTPB)/paraffin fuels applied in hybrid rocket motors enjoy high regression rates and excellent mechanical properties; however, the special microscopic structure of the fuels leads to more complex droplet entrainment mechanisms. The two-dimensional heterogeneous HTPB/paraffin fuels geometry model was established by a dynamic packing algorithm. Dynamic evolution characteristics of a liquid film disturbed by the interaction between HTPB and paraffin were investigated by numerical calculation, and the controlling mechanism of droplet entrainment in a hot shear flow was explored. The results showed that the motion of high-strength HTPB fragments in the liquid film distorted the structure of interfacial wave and generated uncommon rough waves with an averaged wavelength of up to 9.05 mm, for the fuel containing 60 wt. % paraffin. Additionally, there were three pathways of droplet entrainment, i.e., rupturing of paraffin-coated HTPB filaments, splashing at the crest of paraffin wavelets, and the breakup of paraffin ligaments. However, periodic interfacial wavelets were generated for the fuel with a 30 wt. % content of paraffin due to the damping of HTPB, and most of the entrained droplets were generated when the exposed molten paraffin flowed to both ends of the fuel slab. The diameter of entrained droplets was in the range of 0.02–0.74 mm, and it was shown to be positively correlated with the paraffin content, the temperature of shear flow, and the mass flux of shear flow. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the crystallization and barrier properties of oxygen-scavenging polyethylene terephthalate films (OSP) at different stretching ratios and stretching rates. The results show that with the increase of the stretching ratio, more regular lamellar crystal was formed in the biaxially stretched OSP films, and the amorphous phase thickness between lamellae and the long period decreased. The presence of oxygen scavenger acted as heterogeneous nucleation, further promoting the crystallization of the OSP films. This was conducive to prolong the diffusion path of gas molecules through the film. Furthermore, the increase of the stretching ratio expanded the "active" oxygen barrier area of the oxygen scavengers. Thus, the barrier performance of the biaxially stretched OSP films was improved significantly. In addition, the variation of crystallinity and properties of OSP films with the stretching ratio was consistent with the variation with the stretching rate, but the stretching ratio had a greater impact. It was also found that the increase of the stretching ratio and the introduction of oxygen scavenger both increased the stretching strength of the OSP films, while the biaxially stretched OSP film maintained good optical properties. [ABSTRACT FROM AUTHOR]

This research aims to enhance the mechanical characteristics of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by using epoxidized natural rubber (ENR-25 and ENR-50) as a toughening agent and polybutadiene (PB) grafted with maleic anhydride (MA) (3 MA groups/chain) as a compatibilizer. The PHBV/ENR blends were mixed in 100/0, 90/10, 80/20, and 70/30 with PB-g-MA at 0, 5, and 10% (wt./wt.), using an internal mixer set to 175 °C with a rotor speed of 50 rpm. The findings indicated that at 70/30 PHBV/ENR composition, the impact strength of the blends with 25 and 50 epoxide contents were the greatest at 6.92 ± 0.35 J m−1 and 7.33 ± 1.19 J m−1, respectively, which are about two times greater than that of neat PHBV. Furthermore, the biodegradability of the PHBV/ENR blends was more substantial than that of neat PHBV, showing a mass reduction of approximately 40% and 45% for PHBV/ENR-25 and PHBV/ENR-50, respectively. In comparison, while the mass loss of PHBV was approximately 37% after three months of soil burial. The results indicate that ENR improves the toughness of the blends while simultaneously increasing PHBV degradation, which could pave the way for broadening PHBV for sustainability purposes. [ABSTRACT FROM AUTHOR]

This study explored the effect of maleinized polybutadiene (MPB) on the mechanical properties of epoxy resins. Diglycidyl ether of bisphenol-A, an epoxy resin, was modified by incorporating MPB having different molecular weights in order to improve the fracture toughness and peel strength. MPB was mixed with epoxy resin at several concentrations (5, 10, and 15 phr), with the epoxy resin as the major phase and MPB as the minor phase. A comparative study was performed to investigate the influence of MPB on epoxy resins based on their molecular weight difference. Lap shear test results showed that the shear strength of the MPB-modified epoxy resins was superior to that of the neat epoxy resin. At 10 wt% MPB loading, the modified epoxy resin exhibited an 87% enhancement in T-peel strength relative to that of the neat epoxy resin. Moreover, the fracture energy of the modified epoxy system increased proportionally with the amount of MPB in the epoxy matrix. These results indicate that MPB incorporation is a simple and effective method for designing multifunctional epoxy resins, thus facilitating their industrial application in various spheres. [ABSTRACT FROM AUTHOR]

Intrinsic self‐healing materials have drawn great interest in recent years. The design of novel building blocks is essential for developing polymer networks with different properties. Allophanate is usually regarded as a side product during the preparation of polyurethanes. During the research of self‐healing polyurethane networks, we have studied the terminal functionalization of hydroxyl‐terminated polybutadiene with furfuryl isocyanate and occasionally obtained the furan‐terminated polybutadiene allophanate. The tetra‐branched molecule is employed as the crosslinker in the construction of a series of Diels–Alder type polyurethane networks. These polyurethane networks exhibit good mechanical performance and excellent self‐healing ability. Damages can be healed via the thermo‐promoted dissociation and recombination cycle, giving good to excellent recovery of tensile strength within three cycles of "damage‐repair" processes. [ABSTRACT FROM AUTHOR]

Based on the viscous energy dissipation parameter around the crack tip, several intrinsic factors tend to govern the dissipation factor which in turn leads to the characteristic crack growth mechanism of the rubber vulcanizate. Herein, the crack growth behavior of different filled natural rubber (NR), styrene butadiene rubber (SBR), and NR/SBR blends was studied. It was deciphered that the 80/20 NR‐SBR (NSS) compound exhibited the lowest crack growth (dc/dn) value at all strain percentages which was in good accordance with its highest viscous energy dissipation as observed from the DMA (strain sweep) results. Also, from the theoretical calculations, dissipated energy per unit volume for NSS was 4.73 MPa, which was the highest out of all the compounds. This led to a decrement in crack growth. The lowest intensity peak in tan δ versus temperature curve, 6.5% decrement in ΔE'(storage modulus), and almost 44% decrement in ΔG' (Payne Effect) indicates higher polymer‐filler interaction and lower filler‐filler disintegration respectively, as compared to 100 NR (NRS). The results from optical microscopy and scanning electron microscope suggested that NSS exudes the smallest crack deviation and extent of crack growth with lesser filler agglomerates making NSS the best fatigue‐resistant compound. [ABSTRACT FROM AUTHOR]

The excessive migration of plasticizers leads to debonding and cracking of a liner, which can compromise the safety of a solid propellant. Graphene oxide (GO), with a laminar structure as a filler, can effectively reduce the migration of plasticizers. In this study, we modified GO using toluene diisocyanate (TDI). The cross-link density of the substrate was increased by grafting isocyanate groups to obtain a denser liner for the purpose of preventing plasticizer migration. We also used octadecylamine (ODA) to modify GO by grafting negatively charged amide groups on the GO surface. The electrostatic repulsive effect of the amide group on the plasticizer molecules was used to prevent plasticizer migration. Two modified GOs were filled into the hydroxyl-terminated polybutadiene to prepare two composite liners. We then investigated the migration resistance and migration kinetics of each modified liner using the dipping method. In addition, we explored the mechanical properties of each modified liner. Compared with the original liner, the anti-migration and mechanical properties of the modified composite liners were significantly improved. Among them, the TDI-modified liner had the most obvious improvement in migration resistance, while the ODA-modified liner had the greatest improvement in bonding properties. All types of liners met the requirements of the current propellant systems. This study provides an effective reference for improving the migration resistance and bonding properties of the composite liner. [ABSTRACT FROM AUTHOR]

With the continuous development of road construction and maintenance, SBS(Styrene-butadiene-styrene)-modified asphalt is widely used. However, there is no mature method for restoring aged SBS-modified asphalt. This study proposes the use of SBR(polymerized styrene butadiene rubber) and bio-oil for the restoration of aged SBS. In this study, five kinds of recycled asphalt were prepared by adding 5% bio-oil, 10% bio-oil, 6% SBR, 6% SBR + 5% bio-oil, and 6% SBR + 10% bio-oil to long-term aged SBS-modified asphalt. Softening point, penetration, and rotational viscosity experiments were tested to evaluate the conventional properties. Rheological tests revealed the performance of asphalt. Fourier transform infrared spectroscopy (FTIR), and atomic force microscope (AFM) tests were tested to demonstrate the microscopic characteristics of asphalt. Conventional tests investigated that aged asphalt viscosity will increase. Bio-oil could well recycle the asphalt viscosity. SBR could also soften aged asphalt, but its modification effect is limited compared with bio-oil. Rheological tests presented that the SBR and bio-oil have little impact on the temperature sensitivity of SBS-modified asphalt. SBR and bio-oil could decrease the asphalt stiffness. However, SBR and bio-oil could ameliorate the anti-cracking behavior of aged asphalt. The microscopic tests exhibited that SBR and bio-oil could decrease the asphaltene and colloid. Meanwhile, bio-oil could supplement alcohols and ethers at wave number 1000 cm−1–1270 cm−1. Alcohols and ethers are hard to oxidize, something which has a beneficial role in the anti-aged of recycled asphalt. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the influence of types I and II coagents on different polybutadiene isomers vulcanized with organic peroxides. In this study, dicumyl peroxide (DCP) is used in association with coagents ethylene glycol dimethacrylate (EGDMA) and triallyl isocianurate (TAIC) in the crosslinking of high cis‐1,4‐polybutadiene and high vinyl‐1,2‐polybutadiene isomers. The results reveal that using a type I coagent, EGDMA increases the crosslink density as the amount of coagent is increased. The curing index of the samples is positively influenced by coagent type I, mainly when vinyl‐1,2‐polybutadiene is used. [ABSTRACT FROM AUTHOR]

Combined with the Serial Rubber Continuous Mixing Device (SRCMD) and custom‐built rotors, the real continuous regeneration of waste rubber was realized. The upstream mixer effectively solves the problem of pretreatment of waste rubber and realizes its preliminary regeneration. The downstream twin‐screw extruder realizes supplementary regeneration and plasticized extrusion of waste rubber. The optimal process parameters for preparing SRCMD‐reclaimed rubber were explored through orthogonal experiments. Compared to the commercially‐reclaimed rubber produced by the traditional vulcanization tank high‐temperature regeneration method, the SRCMD‐reclaimed rubber well retains the main chain structure of waste rubber and has obvious advantages in various properties. The conveyor belt coverings made by partially replacing styrene butadiene rubber with SRCMD‐reclaimed rubber fully meet the requirements of the national standard in all properties and are better than commercially‐reclaimed rubber, which has good application prospects and provides a guide for promoting the industrial transformation of recycled rubber. [ABSTRACT FROM AUTHOR]

A study on Ba2Ti9O20 and SiO2 ceramic powder-filled polybutadiene (PB) composite substrates was conducted in this paper. The total content of ceramic fillers was a fixed value of 85 wt.% and the SiO2 content varied from 5 to 25 wt.%. The analyses of FTIR, XPS, TEM, Contact Angle testing, and SEM were performed to study the surface characteristics of Vinyltrimethoxysilane (A171)-modified Ba2Ti9O20. The microstructure of composite substrates displayed that Ba2Ti9O20 and SiO2 ceramic fillers distributed in PB homogeneously with a small amount of SiO2 addition. However, SiO2 filler particles agglomerated and poorly dispersed in composites with 25 wt.% SiO2 loading. Furthermore, the effects of SiO2 filler loading on density, porosity, dielectric properties, and mechanical properties of composites were investigated in detail. Last, the composites exhibited medium dielectric constant (ε r = 7.32) , low dielectric loss (tan δ = 0.002), near-zero temperature coefficient of dielectric constant ( τ ε = - 8.07 ppm / ∘ C ) at a high frequency of 10 GHz, relatively low porosity (1.36%), and acceptable bending strength (75.26 MPa) at 65 wt.% Ba2Ti9O20 and 20 wt.% SiO2 fillers loading. [ABSTRACT FROM AUTHOR]

Rubber materials are widely used in aerospace, automotive, smart devices and artificial skin. It is significant to address the aging susceptibility of conventional vulcanized rubber and to impart it rapid self-healing performance for destructive crack damage. Herein, a novel supramolecular rubber elastomer is prepared by introducing metal coordination between carboxyl-terminated polybutadiene and polystyrene-vinylpyridine copolymer. Based on the metal coordination interaction, the elastomer exhibits shape memory and self-healing properties. Moreover, a rapid closure-repair process of destructive cracks is achieved by presetting temporary shapes. This shape memory-assisted self-repair model is shown to be an effective means for rapid repair of severe cracks. An approach to enhance the mechanical and self-healing properties of elastomer was demonstrated by adding appropriate amounts of oxidized carbon nano-onions (O-CNO) into the system. The tensile strength of the elastomer with an O-CNOs content of 0.5 wt% was restored to 83 ± 10% of the original sample after being repaired at 85 °C for 6 h. This study confirms that metal coordination interaction is an effective method for designing shape memory self-healing rubber elastomer. The shape memory-assisted self-healing effect provides a reference for the rapid self-repairing of severe cracks. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotubes (MWCNT) were widely used in nano‐polymer materials due to their excellent electrical and thermal conductivity and mechanical properties. However, the dispersion of MWCNT in the rubber matrix was usually poor due to their large aspect ratio and tendency to agglomerate. The main innovation of this technology was that the non‐covalent modification did not destroy the surface structure and original properties of MWCNT, which was a breakthrough compared to the previous covalent modification. The obtained IL‐MWCNT was still distributed in the water a month after sonication. The microstructural development of the filled network and the uniform dispersion of MWCNT in the presence of IL were analyzed by TEM. The apparent physical (cation–π/π–π) interactions between MWCNT and IL were characterized by Raman spectroscopy and thermal gravimetric analysis (TGA). The high‐performance composites of IL‐MWCNT and nitrile butadiene rubber (NBR) or nitrile butadiene rubber latex (NBRL) were prepared by the liquid latex blending method. The mechanical properties of the composites were improved due to the uniform distribution of IL‐MWCNT in the matrix. As found in this work, the addition of 3 phr of IL increased the mechanical properties of the composites significantly. The continued addition of IL affects the dispersion of MWCNT in the composites due to the plasticizing and diluting effects of IL, which results in a decrease in the mechanical properties. This study provides a simple, environmentally friendly method for the development of IL‐MWCNT composites. [ABSTRACT FROM AUTHOR]