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The non-isothermal crystallization kinetics of the pure ethylene-methyl acrylate copolymer (EMA) and EMA/chloroprene rubber (CR) thermoplastic vulcanizate (TPV) prepared by dynamic vulcanization were extensively investigated using differential scanning calorimetry (DSC). The Avrami method modified by the Jeziorny, the Ozawa and the Mo methods were employed to characterize the non-isothermal crystallization process. The results indicated that the Avrami method modified by the Jeziorny and Mo methods effectively characterized the non-isothermal crystallization behavior of both pure EMA and EMA/CR TPV, while the behavior could not be described by the Ozawa modification method. [ABSTRACT FROM AUTHOR]

This study explores the mechanical and magnetic properties of magnetorheological elastomers (MREs) based on chloroprene rubber, enhanced with carbonyl iron powder (CIP) as the primary filler. Carbon black serves as the primary reinforcing filler, with multi‐walled carbon nanotubes (CNTs) used as a secondary filler to strengthen the rubber matrix. The primary objective of this research is to examine the effects of the mixture of iron powder with reinforcing fillers and the interaction of these fillers with the rubber matrix on the mechanical and magnetomechanical performance of MREs. CNTs, tubular nanoscale carbon molecules, significantly enhance the tensile strength and fatigue resistance when combined with the MRE matrix. During mixing, CNTs form a network structure within the MRE matrix, promoting the dissipation of accumulated heat and reducing thermal fatigue loss. The addition of 20 parts of CNTs to the CR matrix significantly improved the tensile mechanical properties, with the 100% set elongation stress increasing by up to 260% and the magnetic responsiveness increasing by 30.6%. The addition of 10 parts of carboxylated CNTs most notably enhanced the magnetorheological effect, increasing the magnetic stress relaxation rate by 78%. These enhanced properties enable MREs to provide better vibration control and comfort in automotive suspension systems, improve energy absorption and damping effects in industrial damping systems, and enhance durability and sealing performance in sealant applications. Highlights: Carbonyl iron powder, carbon black, and carbon nanotubes (CNTs) were used as fillers to strengthen the chloroprene (CR) matrix magnetorheological elastomers (MREs).CNTs formed a network structure, promoting the dissipation of accumulated heat and reducing thermal fatigue loss.The tensile mechanical property of MRE with 20 parts of CNTs has been significantly improved, with an increasing magnetic responsiveness of 30.6%.Magnetorheological effect of MRE with 10 parts of CNTs has notably enhanced, with the magnetic stress relaxation rate of 78%. [ABSTRACT FROM AUTHOR]

Achieving lead-free flexible materials with excellent γ-ray shielding as well as good mechanical properties are of significance to radiation protection safety and wear comfort of wearable articles. In this paper, polydopamine (PDA) is coated on Bi2O3 particles to form a typical core–shell structure Bi2O3@PDA, which is used to intensely bond bismuth oxide (Bi2O3) with chloroprene rubber (CR). It promotes the interface interaction between Bi2O3 and CR matrix, leading to the uniform dispersion of the filler and rich interfacial compatibility in CR/Bi2O3@PDA composite with as high as 50 wt% filling. Furthermore, 50 wt% CR/Bi2O3@PDA composite displays 53.6% shielding rate for 105 keV γ-rays. Meanwhile, its tensile strength and elongation at break are 9.6 MPa and 1424.8%, respectively, which are without sacrificing too much in comparison with the neat rubber. We propose a versatile route to prepare superior integrated properties of flexible materials, which can be used as wearable articles for radiation shielding. [ABSTRACT FROM AUTHOR]

For the first time, a chloroprene reagent (named as Z-1) has been used against corrosion in various aggressive environments under laboratory conditions. The corrosion protection properties of the reagent Z-1 have been studied in formation waters taken from oil wells No. 2646, 33151, 4012, 31193 and 33016 in operation at Balakhani Oil OGED. Samples made of Ct3 and P-105 brand steels with dimensions of 42x15x5 mm have been used during the tests. Experiments have been performed under dynamic conditions at room temperature for six and twenty-four hours, and the corrosion rate has been determined by gravimetric method. During the experiments, concentrations of 10, 15, 20 and 25 mg/l of Z-1 composition were used. The analysis of results from numerous experiments conducted with both types of steel revealed that the optimal concentration of the composition is 25 mg/l. The protection efficiency of the composition Z-1 in the formation waters of the abovementioned oil wells during the six-hour experiment was as follows: for Ct3 samples, it ranged from 75% to 94%, 75% to 97%, 76% to 98%, 72% to 94%, and 68% to 87%, respectively, while for P-105 steel samples, it ranged from 76% to 96%, 72% to 92%, 73% to 85%, 70% to 90%, and 72% to 96%, respectively. During 24-hour corrosion tests, the protection efficiency of the composition Z-1 was 73-92%, 74-96%, 75-97%, 70-92%, and 66-85% for Ct3 steel samples and 75-94%, 70-91%, 72-83%, 68-89%, and 71-95% for P-105 steel samples, respectively. [ABSTRACT FROM AUTHOR]

Slurry erosion testing is essential for evaluating the durability of materials under erosive conditions. This study examines the slurry erosion behaviours of chloroprene rubber (CR) under varying impact conditions to assess its durability. Traditional mass loss methods and qualitative techniques, including microscopy, SEM, and AFM, were employed to analyse eroded CR samples. Results indicate that cumulative material loss in CR increases linearly with sand impingement after approximately 60 kg of sand and correlates with an impact energy of about 30 kJ. The highest erosion rate was found at an impact angle of 15°. Erosion mechanisms vary with impact angle, affecting surface topography from cutting and ploughing at lower angles to deformation and crater formation at higher angles. Despite their efficacy, these methods are time-intensive and costly. This paper presents a novel approach utilising gloss measurement for continuous, non-destructive monitoring of eroded rubber surfaces. Gloss measurements are 24 times faster than traditional mass loss methods. Correlating gloss values with cumulative material loss, steady-state erosion, and impact energy offers significant time savings and an enhanced understanding of the erosion process. Experimental results demonstrate the effectiveness of gloss measurement as a reliable tool in slurry erosion testing of rubbers. The quantitative output from gloss measurements could support proactive maintenance strategies to extend service life and optimise operational efficiency in industrial applications, particularly in the mining industry. [ABSTRACT FROM AUTHOR]

The superior physical and mechanical performances of halloysite nanotubes (HNTs) make them ideal fillers for rubber reinforcement. However, due to the abundant hydroxyl groups on their surface, they are highly polar and have poor compatibility with polymers, making it difficult for them to disperse uniformly in polymers, thus limiting their application in rubber composites to a certain extent. In this paper, noncovalently modified HNTs filled with a natural rubber/chloroprene rubber/chloro-isobutylene-isoprene rubber (NR/CR/CIIR) blend system, using polydopamine(PDA) as a surface modifier, was investigated. and a green and high-performance PDA/HNTs/NR/CR/CIIR composite was prepared by mechanical blending. Transmission electron microscopy (TEM) showed that the original HNTs had a hollow, multi-walled nanotube structure, and the outer surface of the PDA-modified halloysite nanotubes(PDA/HNTs)showed an obvious cladding layer. X-ray diffraction indicated that the modification experiments did not damage the halloysite crystal structure; the modifier only interacted on the outer surface of the HNTs. Zeta potential and thermogravimetric analysis (TGA) further indicated the presence of interfacial interactions between PDA and HNTs, suggesting that PDA was successfully grafted to the surface of HNTs. In addition, the effects of PDA/HNTs on the mechanical properties, vulcanization properties and Rubber Process Analyzer (RPA analysis) of the NR/CR/CIIR blend were also investigated. The dispersion of HNTs in the NR/CR/CIIR blend was enhanced by the adsorption of PDA on the HNTs surface by non-covalent bonds, and the comprehensive properties of the composites were improved. [ABSTRACT FROM AUTHOR]

For sustainable application of chloroprene rubber (CR), a new technology is developed by the vulcanization of CR using 2,2'-dithiodipyridine (DPD) as a cross-linking agent with the reprocessing performance owing to disulfide metathesis. When DPD was incorporated into CR vulcanization, the Menschutkin reaction between allyl chloride group and pyridine group occurred with a maximum exothermic peak at 184°C. The number of effective cross-linking bond at 0.5 phr DPD vulcanizate was higher than that at high DPD content. This vulcanizate showed high tensile strength (11.12 MPa) and elongation at break (1253 ± 120%) owing to the exchangeable disulfide bond in the system. Under the catalysis of triphenylphosphine, the metathesis of disulfide compound was improved obviously, which endowed CR/DPD vulcanizates with good recyclability performance. Disulfide cross-linkage maintains its stability at low temperature, thus ensuring the mechanical stability of CR/DPD vulcanizate under the ambient conditions. Vulcanization and reprocessing of CR/DPD vulcanizate can be conducted with common industrial rubber processing equipment. Such reprocessable chloroprene rubber could have potential application in CR industry, also serve to significantly improve environmental sustainability. [ABSTRACT FROM AUTHOR]

Water-based chloroprene latex is a solvent-free, environmentally friendly adhesive. Currently, its market demand is growing rapidly. However, there are problems such as a lack of heat resistance and poor mechanical properties, which limit its application. The introduction of vinyl-POSS (OVS) into the resin structure can effectively improve the thermal stability of chloroprene adhesives. In this paper, modified waterborne chloroprene latex was prepared by copolymerization of methyl methacrylate and OVS with chloroprene latex. The results showed that vinyl-POSS was successfully grafted onto the main chain of the waterborne chloroprene latex, and the modified waterborne chloroprene latex had good storage stability. With the increase in vinyl-POSS, the tensile strength of the chloroprene latex firstly increased and then decreased, the tensile property (peel strength of 20.2 kgf) was maintained well at a high temperature (100 °C), and the thermal stability of the chloroprene latex was improved. When the addition amount was 4%, the comprehensive mechanical properties were their best. This study provides a new idea for the construction of a new and efficient waterborne chloroprene latex system and provides more fields for the practical application of waterborne chloroprene latex. This newly developed vinyl-POSS modified chloroprene latex has great application potential for use in home furniture, bags, and seat cushions. [ABSTRACT FROM AUTHOR]

Chloroprene rubber (CR) is frequently quoted as an example of strain‐induced crystallizing elastomer. Many researchers have focused on studying the aging mechanism and mechanical properties of aged CR, little has been done on the effect of crosslinking structure on strain‐induced crystallization (SIC). The present paper related systematic investigations combining the changes of crosslinking structure and its influence on SIC. It was firstly investigated based on FTIR, crosslinking density test and GPC. The results showed that the molecular chains were oxidized in the early stage of aging, but the crosslinking reaction still dominated. At the same time, sol content and polydispersity decreased. In the later stage of aging, CR was oxidized, resulted in severe molecular chains fracture and an increase in the free sol content and polydispersity. The impact of aging on SIC under tensile condition was further investigated by the tensile tests. An obvious stress‐hardening was found for unaged CR, but not in aged CR. The crystallinity and microcrystalline region orientation tests showed that oxidation, crosslinking by double bonds and dechlorination during aging were not conducive to the orientation of molecular chains during stretching. It is the aging process that has an adverse effect on the SIC of CR. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA)‐based thermoplastic vulcanizates (TPVs) were fabricated using dynamic and static vulcanization in the presence of untreated and surface‐treated zinc oxide (ZnO). Initially, the effect of chloroprene rubber (CR) as the elastomeric phase in the PLA‐based thermoplastic elastomer (TPE) was tailored. The CR content varied from 20 to 40 wt%, leading to 46%–70% and 19%–76% decrement in tensile strength and modulus, respectively, while elongation at break increased up to 9–13 times, highlighting the soft rubber phase's impact on ductility. Impact resistance testing showed improved toughness with CR addition, peaking at 20 wt% CR. Scanning electron microscopy (SEM) revealed matrix‐dispersed morphology with increasing CR droplet size, and co‐continuous morphology at 40 wt% rubber in BP6R4. In the next step, the optimized TPE was selected, and the focus shifted to investigate the effect of dynamic/static vulcanization on mechanical properties. It is revealed that adding modified ZnO (ZnO60) increased melt torque, but it decreased after 1.5 min. All vulcanized samples exhibited lower tensile strength and elongation at break but higher elastic modulus due to metallic particle reinforcement. ZnO particle agglomerates and rubber aggregations led to lower mechanical properties. These findings offer quantitative insights into vulcanization's influence on PLA‐based TPVs, informing partially biobased TPEs development and addressing vulcanization limitations. Highlights: Fabrication of biobased thermoplastic elastomer (TPE) and thermoplastic vulcanizate (TPV) based on polylactic acid/chloroprene rubber (PLA/CR) shows the sustainable material prospect.The effects of dynamic/static vulcanization on TPE's behavior are investigated.Micro‐morphology analysis showed dispersed CR phase in TPEs when PLA content is <40 wt%.The addition of modified ZnO through static vulcanization minimized degradation.ZnO Agglomeration and CR aggregations caused subpar TPV mechanical properties. [ABSTRACT FROM AUTHOR]

The carbon fibers were oxidized with concentrated hydrochloric acid, and subsequently modified in two steps. First, the oxidized carbon fibers were grafted with γ‐aminopropyltriethoxysilane (KH550) with the purpose of building a platform on the fiber surface, then the epoxy functionalized elastomer (ethylene‐vinyl acetate‐glycidyl methacrylate terpolymer, EVMG) was grafted on the carbon fiber surface. Chloroprene rubber/natural rubber/carbon fiber (CR/NR/CF) composites were prepared by mechanical blending process. Carbon fibers were characterized by different techniques such as X‐ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA). The results show that EVMG can enhance the interface adhesion between fiber and rubber. It was observed that the surface of the carbon fiber is covered with a layer of the macromolecular film by EVMG, which increases the surface roughness and introduces epoxy groups. On the one hand, carbon fiber and rubber can be entangled through macromolecular chains, and on the other hand, interfacial bonding can be enhanced by chemical interactions. Furthermore, modification by EVMG impacted tensile strength of CF composite increase by 11.05%, the 300% constant tensile stress increased by 21.87%, and the wear resistance increased by 29.8%, respectively. [ABSTRACT FROM AUTHOR]

Five simulation models of chloroprene rubber (CR)/polyurethane (PU) with different composition ratios (9/1, 8/2, 7/3, 6/4, 5/5) are constructed and simulated using molecular dynamics (MD) simulation. The effects of PU content on blend compatibility and mechanical properties are investigated using solubility parameters, the Flory–Huggins interaction parameter, binding energy, glass transition temperature, and the radial distribution function. The objectives of this study are to develop a computational model based on MD techniques to investigate the compatibility and mechanical properties of CR/PU blends. The results of the solubility parameter indicated that PU has good miscibility with CR. The analysis of interaction parameters, binding energy, glass transition temperature, and radial distribution function show that CR/PU blends with mass ratios of 9/1, 8/2, and 7/3 have good compatibility. Moreover, the analyses of binding energy, pair correlation function, and radial distribution function reveal the reasons for the variation in mechanical properties of the blend systems. Additionally, the correctness of the calculation model and the results are verified by experimental tests and analyses. [ABSTRACT FROM AUTHOR]

Elastomers are widely used in many industries. Their use requires thorough knowledge of their strength and stiffness parameters over a wide temperature range. However, determination of the parameters of such materials is still a challenge. Therefore, the paper presents research methodology allowing determination of the properties of rubber-like materials in a wide range of stretch and temperatures (from +50°C to −25°C) by using the example of styrene-butadiene rubber (SBR) and natural rubber (NR) elastomers. Additionally, two blends, chloroprene rubber/nitrile-butadiene rubber (CR/NBR) and NR/SBR blends, were also considered. Based on physical premises, a polynomial and Arruda–Boyce hyperelastic constitutive models parameters were determined using two different methods, namely curve-fitting and the successive response surface method. [ABSTRACT FROM AUTHOR]

Introduction: ß-chloroprene (2-chloro-1,3-butadiene; CP) causes lung tumors after inhalation exposures in rats and mice. Mice develop these tumors at lower exposures than rats. In rats CP exposures cause depletion of lung glutathione (GSH). Methods: PBPK models developed to relate the appearance of mouse lung tumors with rates of CP metabolism to reactive metabolites or total amounts metabolized during exposures have been expanded to include production of reactive metabolites from CP. The extended PBPK model describes both the unstable oxirane metabolite, 2-CEO, and metabolism of the more stable oxirane, 1-CEO, to reactive metabolites via microsomal oxidation to a diepoxide, and linked production of these metabolites to a PK model predicting GSH depletion with increasing CP exposure. Key information required to develop the model were available from literature studies identifying: 1) microsomal metabolites of CP, and 2) in vitro rates of clearance of CP and 1-CEO from active microsomal preparations from mice, rats, hamsters and humans. Results: Model simulation of concentration dependence of disproportionate increases in reactive metabolite concentrations as exposures increases and decreases in tissue GSH are consistent with the dose-dependence of tumor formation. At the middle bioassay concentrations with a lung tumor incidence, the predicted tissue GSH is less than 50% background. These simulations of reduction in GSH are also consistent with the gene expression results showing the most sensitive pathways are Nrf2-regulation of oxidative stress and GSH metabolism. Discussion: The PBPK model is used to correlate predicted tissue exposure to reactive metabolites with toxicity and carcinogenicity of CP. [ABSTRACT FROM AUTHOR]

Designing and preparing chloroprene rubber (CR) with robust mechanical and excellent flame retardancy performance are challenging. In this work, a biomimetic design for high mechanical and flame-retardant CR by synchronous introducing of sacrificial bond (disulfide) crosslinked networks into the chemically crosslinked network is developed based on two new types of vulcanization reactions. Under the catalysis of M g (O H) 2 , the dynamic bond cross-linked network is formed by the reaction between the amino group of cystamine dihydrochloride (CA) and the allylic chlorine group of CR, while the covalently crosslinked network is synchronously formed by two types of nucleophilic substitution reactions in series between M g (O H) 2   and CR. The disulfide bonds serve as sacrificial bonds that preferentially rupture prior to the covalent network, dissipating energy and facilitating rubber chain orientation, so a CA-0.5 sample (CR/CA(0.5 wt%)/ M g (O H) 2 (10 wt%) with dual crosslinked networks exhibits excellent mechanical performance, and the tensile strength and elongation at the break of CA-0.5 are 1.41 times and 1.17 times greater than those of the CR-0 sample with covalently crosslinked networks, respectively. Moreover, the addition of M g (O H) 2 significantly improves the flame retardancy of CR. [ABSTRACT FROM AUTHOR]

Despite being one of the potential candidates for a suitable elastomeric additive to modify asphalt binders, there is a lack of research on using chloroprene rubber (CR). This study evaluates the suitability of using CR to enhance asphalt binder properties, particularly rutting and fatigue performances. Two different grades of asphalt binder (60/70 and 85/100 penetration grade) were modified by 3.5% and 7% CR to meet this end. The conventional physical, high-temperature storage stability, rotational viscosity (RV), dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), and linear amplitude sweep (LAS) tests were used to examine various features of the CR-modified asphalt binder. Results indicate that CR decreases penetration, ductility, and temperature susceptibility and increases softening point and viscosity of the asphalt binder. Additionally, the CR-modified binder can present acceptable pumpability and workability within the construction temperature range. However, the CR-modified binder has phase separation potential, particularly at high modification contents. Based on the results of MSCR and LAS tests, CR can effectively increase the rutting resistance, elastic recovery, and fatigue life of the asphalt binder. Nevertheless, the CR-modified asphalt binder's rutting and fatigue behaviors depend mainly on the grade of the base asphalt binder. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Thermo-oxidative aging plays an important role in changing the properties of rubber materials; it significantly decreases the fatigue life of air spring bags and further causes safety hazards. However, due to the great uncertainty of rubber material properties, an effective interval prediction model has not been established considering the effect of aging on airbag rubber properties. To solve the problem, this study proposes an interval parameter correlation model that can more accurately describe rubber crack propagation characteristics by considering material uncertainty. Furthermore, an aging prediction model of the rubber crack propagation characteristic region is established based on the Arrhenius equation. The effectiveness and accuracy of the method are verified by comparing the test and prediction results under the temperature spectrum. The method can be used to determine the variations in the interval change of the fatigue crack propagation parameters during rubber aging and can guide fatigue reliability analyses of air spring bags. [ABSTRACT FROM AUTHOR]

In this research, a new method to increase the mechanical properties of the low-density polyurethane foams (PUFS) has been described. Chloroprene rubber (CR) is used as reinforcing the mechanical properties of the foam. Polyurethane foam (PUF) containing CR (PUF/CR) and pure PUF were characterized by mechanical testing, Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Differential scanning calorimeter (DSC), Thermogravimetric analysis (TGA). The results of mechanical properties show the tensile strength of PUFS containing 0, 1, 2, 3, 4 and 5 wt% CR are 38.2, 42, 56.4, 61.48, 77.3 and 77.18 kPa, respectively. Also the morphological studies show by increasing the amount of CR in the foam structure, the foam cells are smaller and more closed. Graphical Abstract [ABSTRACT FROM AUTHOR]

Herein, a molecular dynamics simulation method was used to predict the compatibility of chloroprene rubber (CR) and decabromodiphenyl ethane (DBDPE) and to investigate the mechanical properties of CR‐based composites. The limiting oxygen index and cone calorimeter measurement values indicated that the addition of DBDPE was beneficial for reducing the peak heat release rate during combustion and facilitating the formation of compact and strong char layers for carbon black‐filled CR composites, resulting in efficient reduction of flammability and fire risk. Incorporation of DBDPE obviously delayed the dehydrochlorination of the CR matrix. Moreover, adding 50 phr DBDPE had little effect on the tensile strength and elongation at the break, and increased the modulus at 100% elongation by 64.3% in contrast to CR without DBDPE. However, the cold properties of CR vulcanizates decreased slightly with an increase in the DBDPE content. [ABSTRACT FROM AUTHOR]

Introduction: ß-chloroprene (2-chloro-1,3-butadiene; CP) causes lung tumors after inhalation exposures in rats and mice. Mice develop these tumors at lower exposures than rats. In rats CP exposures cause depletion of lung glutathione (GSH).Methods: PBPK models developed to relate the appearance of mouse lung tumors with rates of CP metabolism to reactive metabolites or total amounts metabolized during exposures have been expanded to include production of reactive metabolites from CP. The extended PBPK model describes both the unstable oxirane metabolite, 2-CEO, and metabolism of the more stable oxirane, 1-CEO, to reactive metabolites via microsomal oxidation to a diepoxide, and linked production of these metabolites to a PK model predicting GSH depletion with increasing CP exposure. Key information required to develop the model were available from literature studies identifying: 1) microsomal metabolites of CP, and 2) in vitro rates of clearance of CP and 1-CEO from active microsomal preparations from mice, rats, hamsters and humans.Results: Model simulation of concentration dependence of disproportionate increases in reactive metabolite concentrations as exposures increases and decreases in tissue GSH are consistent with the dose-dependence of tumor formation. At the middle bioassay concentrations with a lung tumor incidence, the predicted tissue GSH is less than 50% background. These simulations of reduction in GSH are also consistent with the gene expression results showing the most sensitive pathways are Nrf2-regulation of oxidative stress and GSH metabolism.Discussion: The PBPK model is used to correlate predicted tissue exposure to reactive metabolites with toxicity and carcinogenicity of CP.

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]

Nonisothermal crystallization kinetics of ethylene–acrylic acid copolymer (EAA) and thermoplastic vulcanizate (TPV) based on EAA/chloroprene rubber (CR) were extensively studied using differential scanning calorimetry. Several methods, including the Avrami, Ozawa, and Mo equations, were carried out to analyze the process of nonisothermal crystallization kinetics of EAA and EAA/CR TPV. The results showed that the Avrami analysis modified by Jeziorny and a method developed by Mo could describe the nonisothermal crystallizations of pure EAA and the EAA/CR TPV very well. However, the Ozawa analysis did not give an adequate description. The crystallization processes of pure EAA and the EAA/CR TPV were accelerated by increasing the cooling rates. Moreover, the initial crystallization temperature and the crystallization termination temperature of EAA/CR TPV were higher than those of pure EAA at the same cooling rate, thus showing the nucleating function of CR in the beginning. While the crystallization half time of EAA/CR TPV was apparently longer than that of pure EAA, meaning that the more CR could cause the steric effect and retard the crystallization process of the TPV during the late stages of crystallizing. Although the CR phase of EAA/CR TPV could provide more nucleation sites, the presence of more CR phase must impose a much more significant confinement effect on the crystal growth of EAA. It was believed that this confinement effect overweighed the nucleation effect, thereby slowing down the overall crystallization rate. [ABSTRACT FROM AUTHOR]

In this paper, a simple and effective strategy was adopted to design a novel heat-triggered shape memory polymers (HSMPs) based on ethylene-vinyl acetate copolymer (EVA)/chloroprene rubber (CR), which can achieve speedily reconfigurable shape fixity and recovery. The morphology image of the HSMPs presented a sea-island structure, and the diameter of the CR particles was 4~8 μm. In the differential scanning calorimetry characterization, it was found that the high EVA content had a high melting transition enthalpy, and the switching temperature was closely related to the melting temperature.The shape memory measurement results showed the shape fixation rate (>95%), shape recovery rate (>95%) and recovery time (<30 s) of these novel HSMPs at suitable environment of 75°C, which can be used as an ideal shape memory material; meanwhile, the optimum weight ratio of EVA to CR and switching temperature were the key factors that determine the shape memory property. Its unique switching temperature ability and outstanding shape memory characteristics were widely used in the field of temperature sensors and automotive engineering. [ABSTRACT FROM AUTHOR]

The article focuses on environmental racism in Louisiana, where residents face high cancer risks from air pollution caused by chloroprene emissions from the Pontchartrain Works Facility. Topics include Efforts to reduce chloroprene emissions have been inadequate, and communities of color, who are impacted by environmental hazards; and Lawyers supporting environmental justice communities considering nontraditional strategies such as facilitating citizen science to address structural racism.

Synthesized graft copolymers of chloroprene rubber with acrylic acid in a solution of a mixture of dimethylformamide and benzene, in the presence of potassium persulfate. The gravimetric method determined the orders of the reaction rate by the concentrations of acrylic acid (2.0) and potassium persulfate (1.2), the total activation energy of the process (24.4 kJ/mol). It was found that the degree of grafting increases up to 140% with an increase in the concentration of the monomer, initiator, temperature, and process time. The efficiency of grafting changes insignificantly with changes in synthesis conditions and has a high value (67%–91%) over a wide range of concentrations, temperatures, and times. With an increase in the concentration of acrylic acid and a process time of up to 8 h, the molecular weight of the grafted polyacrylic acid chains increases to 38,000. IR Fourier, 1H, and 13C NMR spectroscopic studies established the mechanism of graft copolymerization. Radical active centers are formed as a result of hydrogen abstraction from the rubber molecule after interaction with potassium persulfate. Copolymers synthesized at a mass ratio of rubber:acrylic acid from 1:0.5 to 1:2, have excellent adhesion to the surface of the skin and textile material. [ABSTRACT FROM AUTHOR]

This correction notice addresses an error in Scheme 6 of a publication titled "Interelastomer Reactions Occurring during the Cross-Linking of Hydrogenated Acrylonitrile-Butadiene (HNBR) and Chloroprene (CR) Rubbers Blends in the Presence of Silver(I) Oxide (Ag 2 O) and Mechanical Properties." The mistake involved a typing error in the presentation of carbon atoms. The corrected Scheme 6 has been provided, and the authors assure that the scientific conclusions remain unaffected. The correction has been approved by the Academic Editor, and the original publication has been updated. [Extracted from the article]

Three different blending procedures were used to create multiwalled carbon nanotube (MWCNT)-modified chloroprene rubber (CR)/natural rubber (NR) blended composites (MWCNT/CR–NR). The effects of the blending process on the morphology of the conductive network and interfacial contacts were researched, as well as the resistance–strain response behavior of the composites and the mechanism of composite sensitivity change under different processes. The results show that MWCNT/CR–NR composites have a wide strain range (ε = 300%) and high dynamic resistance–strain response repeatability. Different blending procedures have different effects on the morphology of the conductive network and the interfacial interactions of the composites. If the blending procedures have wider conductive phase spacing and stronger interfacial contacts, the change in the conductive path and tunneling distance occurs more rapidly, and the material has a higher resistance–strain response sensitivity. [ABSTRACT FROM AUTHOR]

In order to solve the problem of poor thermal conductivity of polymer‐based radiation shielding composite materials, h‐BN@PDA@PbWO4 hybrid powders were prepared by combining h‐BN with high thermal conductivity and PbWO4 with γ shielding. With the assistance of polydopamine, PbWO4 particles were synthesized in situ on the h‐BN surface. The effects of h‐BN@PDA@PbWO4 on thermal conductivity, γ‐ray shielding, and mechanical properties of chloroprene rubber were studied. The results showed that the hybrid particles had better dispersibility than the pure mixing of h‐BN and PbWO4 in chloroprene rubber and significantly improved the thermal conductivity gamma‐ray shielding performance and mechanical properties of CR composites. When the filler content of the hybrid powder reaches 40 wt%, the thermal conductivity of the composite is about 3.16 times that of the pure CR. The γ shielding rates at 86.5 KeV and 105.3 KeV photon energies increase by 14.14% and 17.61% compared with the pure CR. Compared with pure CR, the tensile strength of the composites increased by 4.79 MPa, and the elongation at break decreased slightly. These were because h‐BN@PDA@PbWO4 shows had an excellent synergistic effect in CR substrate. The new kind of CR/h‐BN@PDA@PbWO4 composite can be used for thermal management and gamma shielding. [ABSTRACT FROM AUTHOR]

Maleic anhydride was chemically attached to depolymerized natural rubber, and the product was named as carboxy-terminated liquid natural rubber (CTNR). The CTNR can act as a potential plasticizer in chloroprene (CR) vulcanizates. This paper describes the use of commercial nano silica (NS) as a promising cost-effective filler, which can enhance the tensile properties and ageing resistance of the CR vulcanizates incorporated with CTNR (CR-CTNR). The enhancement in properties may be attributed to the increased bound-rubber content owing to the large surface area of the nano-sized filler. The characteristics of the NS-filled CR vulcanizates containing CTNR (NS CR-CTNR) were compared with those containing amorphous silica. The NS CR-CTNR vulcanizates showed superior ageing and oil resistance due to the finer rubber filler interaction modified by ionic cross linking. [ABSTRACT FROM AUTHOR]

The curing system plays a vital role in designing rubber compounds for various industrial applications. Therefore, it is paramount to establish viable curing strategies for any new elastomer to explore its application potentials and commercial significance. Impacts of different curing regimes on the properties of a recently developed copolymer of chloroprene and acrylonitrile (acrylonitrile-chloroprene rubber, NCR) are reported here. Several primary accelerators (four from thiourea- and one from thiazolene product families) were used for curing the new rubber along with fixed loadings of zinc oxide (5 phr) and magnesium oxide (4 phr). Besides, curatives based on sulfur and peroxide were also evaluated. The influence of different curing systems on the rheological and physical properties of the copolymer was explored. It has been seen that the properties of the copolymer are considerably influenced by the different curing systems used. While ethylene thiourea (ETU) and propylene thiourea (PTU), as primary accelerators, provide the highest state of cure but may cause scorch. The use of trimethyl thiourea (TMU), on the other hand, results in the fastest rate and the most stable state of cure, good scorch safety, bin stability, and an overall good balance of properties. The sulfur-based crosslinking system induces good mechanical properties but causes limited bin stability, poor high-temperature compression set, and impaired heat resistance properties. As a curing agent, peroxide delivers the best bin stability in the rubber stocks but yields higher stiffness and limited aging resistance in the vulcanizates. [ABSTRACT FROM AUTHOR]

In the production of chloroprene rubber, acetylene dimerization over the Nieuwland catalyst is an important step. The addition of Mg2+ to the Nieuwland catalyst improves the acetylene conversion and the selectivity toward vinyl acetylene. In this study, active component crystal structure, the role of Mg2+ in the Nieuwland catalyst, the reason for the catalyst deactivation, and the reaction mechanism were analyzed by different characterization techniques. The results indicate that the main reason for the Nieuwland catalyst deactivation is the loss of Cu2+. The addition of Mg2+ will increase the exposure of active sites, reduce the residence time of acetylene in the catalyst, and inhibit the reduction of Cu2+, thereby improving the catalytic performance and stability of the catalyst. [ABSTRACT FROM AUTHOR]

Chloroprene rubber (CR) has been commonly applied in various branches of the industry but its application in selective layers of pervaporation membranes remains overseen. To survey its applicability, we report on the pervaporation of two close‐boiling azeotrope‐forming systems of common solvents, blowing agents, adjuvants, and refrigerants, namely, dichloromethane‐cyclopentane (DCM‐CP) and methylal‐cyclopentane (ML‐CP). Vulcanizates having the form of thin films (66 ± 5 μm) have been prepared from the crystallization‐resistant (WRT) polychloroprene by using nanoparticles of ZnO and MgO. Mechanical and thermal properties have been characterized using dynamic mechanical analysis (DMA) and thermogravimetry analysis, spectral properties using ATR‐FTIR. Plasticization has been assessed by measuring DMA characteristics for the CR films exposed to vapors of the studied compounds. The CR films are preferentially permeable to DCM and ML over CP, break the respective azeotropes, and show comparable selectivity ranging from 1.1 to 1.7 for DCM‐CP and from 1.0 to 1.8 for ML‐CP. Importantly, plasticization of the CR membranes by DCM and ML enhances the selectivity and, simultaneously, the transmembrane flux. Overall, we show that membranes from CR enable selective and intensive pervaporative recovery of halogenated hydrocarbons from their mixtures with hydrocarbons, which is relevant, for instance, for the recycling of blowing agents. [ABSTRACT FROM AUTHOR]

The random copolymer of chloroprene and acrylonitrile is a newly developed rubber whose features and value propositions are not scientifically explored yet. This article focuses on the basic characterizations and properties of acrylonitrile-chloroprene rubber. Qualitative analyses through infrared (FTIR) and nuclear magnetic resonance (1H-NMR) spectra confirm the presence of both the -Cl and -CN groups in the new rubber. As evidenced through differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA), the single glass transition temperature of acrylonitrile-chloroprene rubber reflects its monophasic random microstructure. While compared against commercial grades of chloroprene rubber (CR) and nitrile rubber (NBR), the new rubber provides a distinctive combination of properties that are not available with either of the elastomer alone. Acrylonitrile-chloroprene rubber demonstrates slightly lower specific gravity, an improved low-temperature compression set, higher flex-fatigue resistance, and lower volume swelling in IRM 903 and Fuel C to chloroprene rubber. As compared to nitrile rubber, the new copolymer shows appreciably better heat aging and ozone resistance. Good abrasion resistance, low heat buildup, and remarkably high flex-fatigue resistance indicate excellent durability of the acrylonitrile-chloroprene rubber under dynamic loading. Based on the preliminary results, it is apparent that the new copolymer can be a candidate elastomer for various industrial applications which demand good fluid resistance, high heat and low-temperature tolerances, good weatherability, and durability under static and dynamic conditions. [ABSTRACT FROM AUTHOR]

The effect of organomodified montmorillonite (MMT) content and mixing conditions on the mechanical properties, structure, and morphology of a chloroprene rubber was investigated. Nanoparticles were mechanically mixed with a plasticizer, followed by ultrasonic homogenization before compounding of all ingredients of the mixtures in two-roll mills. Mechanical tests were carried out on samples prepared with three sonication amplitudes and containing different amounts of montmorillonite. The tensile strength and energy to break were found to increase by 15 and 70%, respectively, at the highest nanoclay content but the crack growth rate and tearing energy decreased. Variations in the mixing amplitude and MMT content did not influence the DSC and TGA thermograms, confirming an unchanged thermal stability of the nanocomposites. The highest sonication amplitude led to rubber mixtures with more uniform and homogeneous morphologies, with clay nanoparticles well dispersed and embedded in the rubber matrix. [ABSTRACT FROM AUTHOR]

The limited options of suitable elastomers with adequate cost‐performance balance drive the necessity to introduce new materials in the oil & gas (O&G) application space. The relevance of a recently developed copolymer of chloroprene and acrylonitrile (referred to as acrylonitrile–chloroprene rubber or NCR) to O&G applications is described in this technical contribution. The new elastomer demonstrates adequate physical properties and reasonably good high and low‐temperature capabilities. It offers good resistance to several aqueous and non‐aqueous fluids with low volume swelling and retains its physical properties to reasonable extents while exposed to hot test oils. Acrylonitrile–chloroprene rubber has been found to sustain "sour gas" exposure. Good abrasion resistance, high tear strength, and remarkably high flex‐fatigue resistance coupled with low heat build‐up reflect its durability under dynamic conditions. In addition, acrylonitrile–chloroprene rubber can very well withstand the rapid gas decompression test at 25°C. This unique combination of attributes may allow acrylonitrile–chloroprene rubber to be considered as a candidate material for high‐performance O&G applications. [ABSTRACT FROM AUTHOR]

Vulcanization at lower temperatures can be considered as a good alternative to reduce both investment and operation costs for cable insulation sheat and special purpose hose production lines. In this study, silane vulcanization of chlorinated polyethylene and chloroprene rubber blends at lower temperature was investigated. Rubber compounds were prepared by using internal mixer instead of an extrusion system which is widespread used for projected applications. Rheological and dynamic properties of the rubber compounds were studied. After vulcanization, physico‐mechanical, thermal, morphological and temperature scanning stress‐relaxation properties were investigated before and after thermal aging. Structural analysis was performed by using Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy so as to identify vulcanization reaction mechanism. All the compound compositions could be vulcanized at 110°C in the presence of water. Amino silane was found to be more effective than epoxy silane. [ABSTRACT FROM AUTHOR]

This correction notice is for an article titled "Preparation and Characterization of Polydopamine-Modified Halloysite Nanotubes and Their Effect on a Natural Rubber, Chloroprene Rubber and Chloro-Isobutylene-Isoprene Rubber Blend." The authors of the article are Yanbing Hou, Yiwen Sun, Rui Wang, Yandan Zhang, Fusheng Liu, and Jingjie Han. The correction addresses an error in the originally published version of the manuscript, specifically in table 2. The correct table 2, which includes the formula of NR, CR, and CIIR, is provided in the correction notice. [Extracted from the article]

This study shows an approach of compatibilization between ethylene‐propylene diene monomer (EPDM) and Chloroprene Rubber (CR) by using nanosilica (SiO2) as a compatibilizer and, at the same time, as a strong reinforcing nanofiller. The effect of nanosilica and rubber composition was studied on microstructure and mechanical properties of the cured EPDM/CR/SiO2. The microstructure of compounds were characterized using scanning electron microscopy and transmission electron microscopy, which demonstrated that the observed nanoSiO2 were in both EPDM and CR phases. It was found that the addition of nanosilica had massive improvement on modulus, tensile strength, and dynamic mechanical thermal analysis of the samples. With the incorporation of just 10 phr nano‐SiO2, the storage modulus above the glass transition region of CR50 increased from about 3.9 to 7.16 MPa. Moreover, the investigation of glass transition temperature (Tg) values showed that the compatibility of EPDM and CR in the compound enhanced with the addition of nanosilica, which in turn contributes to improving the properties of compounds. In addition, the results of mechanical properties of the samples revealed that the tensile strength, elongation at break and modulus of CR50 after modifying with 10 phr of nanosilica increased by around 398%, 33%, and 135%, respectively. [ABSTRACT FROM AUTHOR]

In this study, the Friedel–Crafts alkylation was realized in a solvent free processing of styrene–acrylonitrile copolymers/chloroprene rubber (SAN/CR) molten blending which contributes the formation of SAN-co-CR co-polymers and improved compatibility between SAN and CR. The properties of several Lewis acid compounds were tested as catalysts among which AlCl3 was the most efficient. The effects of blending temperature and time on the co-polymer formation in situ were also investigated. The methodology of weighing and Fourier transform infrared analyses indicated that the reaction degree increases with increasing blending temperature and time in the ranges of this study. The micro-structures and reaction mechanisms of the resulted SAN-co-CR polymers and morphological structures of SAN/CR/AlCl3 blends were characterized as well by differential scanning calorimetry, FT-IR spectra, GPC and scanning electron microscopy. The results showed that the inter-facial reactions between SAN and CR have been effectively improved. Moreover, the inter-chain structure of SAN-co-CR co-polymers was proposed which is different from general grafting or blocking co-polymers. [ABSTRACT FROM AUTHOR]

Objectives: To update the U.S. portion of an historical cohort mortality study of workers with potential exposure to chloroprene (CD) and vinyl chloride (VC) with focus on lung and liver cancer. Methods: Subjects were 6864 workers from two sites with vital status determined through 2017 for 99% of subjects and cause of death for 97.2% of deaths. Historical exposures to CD and VC were estimated quantitatively. We performed external and internal mortality comparisons. Results: External comparisons revealed mostly deficits in deaths; internal comparisons revealed no consistent evidence of exposure-response relationships with CD or VC. Conclusions: Our update continues to support the conclusion that the risk of death from lung or liver cancer is unrelated to exposure to CD or VC at levels experienced by workers in the two U.S. sites. [ABSTRACT FROM AUTHOR]

Highly crosslinked elastomer-iron oxide composite for grinding as well as for polishing application. With the recent introduction of organic acid-based coolants in polishing applications, the designed composites should have good resistance to oils. This investigation reports the preparation and properties of high crosslinked elastomer-iron oxide composites based on Chloroprene Rubber (CR) as well as on Nitrile Rubber (NBR) as main elastomer matrix and their comparative study. In NBR system, a small amount of natural rubber (NR) was used to improve the abrasion resistance. The crosslink density (CLD) was determined from the plateau modulus in DMA using Nielsen's model. CLD was also determined based on the equilibrium-swelling ratio by using Flory-Rehner model. The CLD at lower cure time estimated by both methods was substantially different. Nevertheless, it converges to a common value at highly crosslinked state. Highly crosslinked CR shows 500% higher modulus at high temperature when compared to the NBR system. Highly crosslinked elastomeric composites based on Chloroprene Rubber (CR) as well as Nitrile Rubber (NBR) with high iron oxide content were prepared. This investigation gives insights into the fabrication of composites and evaluates the network structure of highly crosslinked composites. Different models were used to characterize the elastomeric network structures in the composites. [ABSTRACT FROM AUTHOR]

Electrical resistance of the elastomeric material polychloroprene filled with multiwalled carbon nanotubes (CNTs) dispersed by using an imidazolium based ionic liquid has been measured experimentally and calculated theoretically, as a function of the applied compression/decompression force F. Both experimental and theoretical results show that the electrical resistance R of the composite exhibits non-monotonic dependence on F. This observed non-monotonic dependence R(F) is explained by different mechanisms of conductivity that are specific to the respective domains of the magnitude of the compression/decompression force F. At small F, the observed decrease of conductivity with increasing F is found to be caused by the change of an average contact distance between CNTs. At higher F, the observed increase of R with increasing F is caused by the dependence of the per-particle surface area on F. The experimentally observed dependence R(F) is adequately described by the developed theory that relies on establishing the exact relation between the CNT network structure and the electrical response of the composite. Theoretical dependence between the conductivity of the composite and the applied stress is obtained using the percolation model of the electrical conductivity of CNT network that shows excellent quantitative agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Selection of a suitable thermal aging process could render desirable mechanical properties of the rubbers or blended rubbers. In this work, the effect of the aging processes on the mechanical properties and activation energies of natural rubbers (NR) and NR/chloroprene rubbers (CR) blends with low CR contents (5–10%) was investigated. Three aging processes including heat aging (at 110°C for 22 hours), mechanical aging (under dynamic loading to 140% strain for 16000 cycles), and complex aging (heat and mechanical aging) were studied. The results revealed that the compatibility of CR in natural rubber matrix had a significant effect on the dynamic properties of the blended rubber and negligible effect on the static properties. The changes in activation energies of the blended rubber during aging processes were calculated using Arrhenius relation. The calculated changes (ΔUc, ΔUd, and ΔUT) in activation energies were consistent with the results of mechanical properties of the blended rubber. Interestingly, the change in activation energies using complex aging conditions (ΔUc) was mostly equal to the total changes in activation energies calculated separately from heat aging (ΔUT) and mechanical aging (ΔUd) conditions. This indicates that, in complex aging conditions, the heat and dynamic loading factors act independently on the properties of the blended rubber. [ABSTRACT FROM AUTHOR]

This study was carried out in order to investigate retardation time of chloroprene rubber (CR) latex on the cementitious system in relation to its effect on the heat of hydration of cementitious system. Set times, consistency and heat evolution tests were carried out on ordinary Portland cement (OPC). Three different curing environments were selected with different CR to cement ratio i.e., 0%, 5%, 10%, 15% and 20%. The data revealed that consistency was increased under high temperature and low relative humidity for cement pastes. While achieving standard consistency, water required by the controlled specimen was reduced by 43% with the addition of 20% CR latex. Regarding heat of hydration, it was found that heat of hydration of latex-modified cement pastes was higher than the controlled cement paste after 48 h. [ABSTRACT FROM AUTHOR]

Chloroprene-filled CNT rubber has been investigated for the electromagnetic shielding application. Nevertheless, there are continuous studies to overcome CNTs agglomeration, materials loss and air contamination issues generated during conventional melt compounding process. Thus, the current study proposes the usage of polar and low molecular weight ethanol solvent as dispersant for CNT fillers and silane-based Si-69 as coupling agent. Si-69 is a widely used fillers' coupling agent because of its reliable performance in the industrial-scaled rubber compounding process. This study is to investigate the effect of carbon nanotube (CNT)-Silane addition as secondary fillers on tensile strength, elastic modulus and cure characteristics of hloroprene rubber (CR)- filled carbon black (CB) compound. The CR-filled CB was prepared by internal mixing, followed by roll-mill process in which CNT-Silane dispersion was added. For comparison, the samples of CR-filled CB without CNTs addition and with as-received CNTs addition were prepared and characterized. The CR composite added with CNT-Silane dispersion displayed tensile strength and elastic modulus (at 300% elongation) of 23 MPa and 18 MPa respectively, which are 4% higher than the CR composite added with asreceived CNTs. The findings were supported by the FESEM micrograph of tensile fracture samples that showed the CNT-Silane addition produced better CNTs dispersion in the CR-filled CB compound. Furthermore, the usage of CNT-Silane improved the CR-filled CB compound processibility by reducing the minimum (ML) and maximum torque (MH) values from 0.34 and 1.11 N.m in as-received CNT samples to 0.32 and 1.04 N.m respectively in CNT-silane samples. [ABSTRACT FROM AUTHOR]

Natural rubber is widely known to possess good mechanical properties. However, due to the existence of numerous reactive double bonds on the molecular backbone, natural rubber is highly susceptible to degradation by thermal aging. To overcome such shortcomings, natural rubber is frequently blended with synthetic rubbers such as chloroprene rubber. Chloroprene rubber is one of the most important specialty rubber for nontire application, for example rubber fender. The present study investigates the effects of two different blend ratios of natural rubber (standard Indonesian rubber or SIR 10) and chloroprene rubber on the cure, tensile properties, and morphology of rubber blends. The blends of SIR 10/chloroprene rubber are prepared by using laboratory kneader and laboratory two‐roll mill. Rubber blending is made from mixture of natural rubber SIR 10 and synthetic rubber chloroprene rubber with variation of SIR 10/chloroprene rubber ratio PF1 100/0; PF2 70/30; PF3 30/70; PF4 0/100 phr. Furthermore, each variable is tested to determine the rheological and mechanical properties including tensile strength, elongation at break, hardness, and compression set. The addition of chloroprene rubber also causes an increment in the tensile strength and elongation at break. However, only PF3 shows satisfied result compared to the requirements standard (ISO 17357‐1:2014 Ship and Marine Technology‐Floating Pneumatic Rubber Fenders). [ABSTRACT FROM AUTHOR]

β‐Chloroprene is used in the production of polychloroprene, a synthetic rubber. In 2010, Environmental Protection Agency (EPA) published the Integrated Risk Information System "Toxicological Review of Chloroprene," concluding that chloroprene was "likely to be carcinogenic to humans." This was based on findings from a 1998 National Toxicology Program (NTP) study showing multiple tumors within and across animal species; results from occupational epidemiological studies; a proposed mutagenic mode of action; and structural similarities with 1,3‐butadiene and vinyl chloride. Using mouse data from the NTP study and assuming a mutagenic mode of action, EPA calculated an inhalation unit risk (IUR) for chloroprene of 5 × 10−4 per µg/m3. This is among the highest IURs for chemicals classified by IARC or EPA as known or probable human carcinogens and orders of magnitude higher than the IURs for carcinogens such as vinyl chloride, benzene, and 1,3‐butadiene. Due to differences in pharmacokinetics, mice appear to be uniquely responsive to chloroprene exposure compared to other animals, including humans, which is consistent with the lack of evidence of carcinogenicity in robust occupational epidemiological studies. We evaluated and integrated all lines of evidence for chloroprene carcinogenicity to assess whether the 2010 EPA IUR could be scientifically substantiated. Due to clear interspecies differences in carcinogenic response to chloroprene, we applied a physiologically based pharmacokinetic model for chloroprene to calculate a species‐specific internal dose (amount metabolized/gram of lung tissue) and derived an IUR that is over 100‐fold lower than the 2010 EPA IUR. Therefore, we recommend that EPA's IUR be updated. [ABSTRACT FROM AUTHOR]