Chlorobutyl Rubber Research Articles

Design of regulable chlorobutyl rubber damping materials with high-damping value for a wide temperature range

In this paper, a kind of specific damping material with high damping and wide effective damping temperature range (ΔT) was designed by regulating glass transition temperature (Tg). The damping material was prepared based on chlorobutyl rubber (CIIR), which exhibits high initial damping performance but also low Tg and narrow ΔT. 40 phr carbon black (CB) was added to promote the Tg of CIIR as well as acted as the reinforcing agent. Simultaneously, different dosages of terpene resin (TR) were incorporated to further control the Tg and ΔT, and improve the interfacial compatibility between CIIR with CB. Consequently, the Tg and ΔT of the composites could be regulated by changing the amount of TR under the premise of ensuring good damping and mechanical properties. Especially, when the content of TR was 30 phr, the Tg of composite was tuned from −30 °C of blank sample to 0 °C and ΔT was widen from (−60 °C, 35 °C) to (−60 °C, 60+ °C). Maximum loss factor (Tanδmax) was increased from 1.1 to 1.3 as well. In addition, this kind of damping material possessed outstanding actual shock absorption and noise reduction performances corroborated by resonance test and noise reduction test. Therefore, this damping material shows great potential in high-quality damping rubber products.

Vulcanization kinetics and mechanical properties of organically modified nanoclay incorporated natural and chlorobutyl rubber nanocomposites

The curing kinetics, vulcanizate properties, mechanical reinforcement and chemical interactions of organically modified nanoclay filled natural rubber (NR) and chlorobutyl (CIIR) rubbers have been studied. From the vulcanization studies, it is observed that nanoclays are more intercalated in NR matrix rather than CIIR matrix. To understand the exact mechanism operating in the vulcanization behavior of NR and CIIR, autocatalytic model was applied. The vulcanization kinetic studies revealed that the nanoclay distribution at high temperature (190 °C) in CIIR matrix is somewhat intercalated in nature. Highly pronounced reversion behavior was observed in NR matrix. The mechanical reinforcement of vulcanizates was examined using the change in modulus values at 100% and 300% elongation. The mechanical properties were modeled using different kind of models such as Guth-Smallwood, Halpin-Tsai, modified Halpin-Tsai and Mori-Tanaka models. Finally, the dispersion of nanoclay platelets in CIIR and NR matrix was confirmed by the phase images obtained from AFM technique.

Modeling of dielectric properties of Chlorobutyl rubber nanocomposites

Abstract Chlorobutyl rubber comprises a significant type of butyl rubber with attractive properties. Inspection of the various aspects of the dielectric properties of chlorobutyl rubber nanocomposites containing organically modified layered silicates (nano clay) in a particular range of frequency was carried out at different filler loadings. Owing to the interaction of the organically modified silicate layers with the chlorobutyl rubber matrix, a conductive pathway is created which enables the improvement in the dielectric properties of the nanocomposites. A comparative study of the dielectric properties of composites containing various types of organically modified layered silicates was done. Modeling of the dielectric properties were done and the relevance of experimental results were evaluated with the existing models.

Effective reuse of CIIR nanocomposite based CPC by the evaluation of thermal decontamination as well as gas barrier properties

Abstract Nanocomposite technology opens up a new era in the study of polymeric materials. Carbon nanotubes, due to their extremely high mechanical strength finds use as a filler material in many polymer matrices and can be viewed as one of the most promising area driven towards commercial applications. Nevertheless nanoclay is also equally good as filler in increasing the mechanical, barrier as well as thermal characteristics of chlorobutyl rubber (CIIR) matrix. The synergistic effect produced by nanoclay and carbon nanotube in enhancing the properties of chlorobutyl rubber enhances its efficacy towards the fabrication of industrially relevant materials. The nanocomposites were prepared using cloisite 30 B and carbon nanotubes separately and a hybrid nanocomposite was prepared by incorporating these two fillers to evaluate the synergistic effect of the fillers. The mechanical, dielectric, solvent diffusion and barrier properties of the nanocomposites were analyzed. The results show an enhancement in the aforementioned properties and reveal that both the carbon nanotubes and nanoclay contribute synergistically towards the enhancement in properties. Moreover the enhanced solvent resistance as well as gas barrier properties suggests the feasibility of the utilization of the material in the production of chemical protective clothing. Evaluation of thermal decontamination of the proposed CPC material reveals its potential for its effective reuse.

Effects of Electron Beam Irradiation on the Mechanical, Thermal, and Surface Properties of Some EPDM/Butyl Rubber Composites.

The effects of electron beam irradiation on the properties of ethylene propylene diene monomer (EPDM)/butyl rubber composites in presence of a polyfunctional monomer were investigated by means of differential scanning calorimetry (DSC), thermal analysis, scanning electron microscopy (SEM), attenuated total reflection absorption infrared spectroscopy (ATR-IR), and mechanical and surface energy measurements. The samples were exposed over a wide range of irradiation doses (20–150 kGy). The EPDM matrix was modified with butyl rubber, chlorobutyl rubber, and bromobutyl rubber. The gel content and crosslink density were found to increase with the electron beam irradiation dose. The values of the hardness and modulus increased gradually with the irradiation dose, while the tensile strength and elongation at break decreased with increasing irradiation dose. The EPDM/butyl rubber composites presented a higher thermal stability compared to the initial EPDM sample. The incorporation of butyl rubbers into the EPDM matrix led to an increase in material hydrophobicity. A similar trend was observed when the irradiation dose increased. The greatest change in the surface free energy and the contact angles occurs at an irradiation dose of 20 kGy. The Charlesby–Pinner plots prove the tendency to crosslinking as the irradiation dose increases.

The Synergistic Effect of a Mixture of the Oligomer of 2,2,4-Trimethyl-1,2-Digidrochinoline and Polymeric Petroleum Resin on the Adhesion of Chlorobutyl Rubber to Steel

Studies have been carried out to increase the adhesion and heat resistance of insulating tape coatings based on chlorobutyl rubber applied on pipelines. It is shown that the synergistic effect of the growth of adhesion of chlorobutyl rubber to steel by the co-administration of the oligomer of 2,2,4-trimethyl-1,2-dihydroquinoline and polymeric petroleum resin is due to the increased interaction of the oligomer with chlorobutyl rubber under the action of a polymeric petroleum resin and the high adhesion of the oligomer to steel.

Organo-modified layered silicate nanocomposites of EPDM–chlorobutyl rubber blends for enhanced performance in γ radiation and hydrocarbon environment

In this work, blends of ethylene propylene diene monomer rubber and chlorobutyl rubber were reinforced with organo-modified layered silicate (nanoclay) to enhance their performance in radiation as well as hydrocarbons environments. The mechanical properties of the nanocomposites increased (up to 57%) and solvent transport coefficients decreased (by 30%) with increasing nanoclay content. The enhancement in properties was attributed to the dispersion of nanoclay platelets in the ethylene propylene diene monomer–chlorobutyl rubber blends and the chemical interaction between nanoclay and the polymer which were confirmed by morphological and spectroscopic analysis, respectively. The effect of nanofiller content on the mechanical properties, solvent uptake and thermal degradation of blends exposed to gamma radiation was investigated by irradiating the nanocomposites with gamma rays for cumulative doses of 0.5, 1 and 2 MGy. The ethylene propylene diene monomer–chlorobutyl rubber nanocomposites with 5 phr nanoclay had the best retention of mechanical properties and solvent sorption coefficients on exposure to radiation. Depending on the dose of cumulative radiation exposure, chain scission and/or crosslinking occurred in the nanocomposites, resulting in varying degrees of changes in properties.

Butyl Rubber Nanocomposites with Monolayer MoS₂ Additives: Structural Characteristics, Enhanced Mechanical, and Gas Barrier Properties.

Emerging two-dimensional (2D) materialsm, such as molybdenum disulfide (MoS2), offer opportunities to tailor the mechanical and gas barrier properties of polymeric materials. In this study, MoS2 was exfoliated to monolayers by modification with ethanethiol and nonanethiol. The thicknesses of resulting MoS2 monolayers were 0.7 nm for MoS2-ethanethiol and 1.1 nm for MoS2-nonanethiol. MoS2 monolayers were added to chlorobutyl rubber to prepare MoS2-butyl rubber nanocomposites at concentrations of 0.5, 1, 3, and 5 phr. The tensile stress showed a maximum enhancement of about 30.7% for MoS2-ethanethiol-butyl rubber and 34.8% for MoS2-nonanethiol-butyl rubber when compared to pure chlorobutyl rubber. In addition, the gas barrier properties were increased by 53.5% in MoS2-ethanethiol-butyl rubber and 49.6% in MoS2-nonanethiol-butyl rubber. MoS2 nanosheets thus enhanced the mechanical and gas barrier properties of chlorobutyl rubber. The nanocomposites that are presented here may be used to manufacture pharmaceutical stoppers with high mechanical and gas barrier properties.

ENHANCING THE REVERSION RESISTANCE, CROSSLINKING DENSITY AND THERMO-MECHANICAL PROPERTIES OF ACCELERATED SULFUR CURED CHLOROBUTYL RUBBER USING 4,4′-BIS (MALEIMIDO) DIPHENYL METHANE

ABSTRACT Vulcanizates of chlorobutyl rubber (CIIR) with the accelerated sulfur generally exhibit poor crosslinking density owing to the low level of unsaturation in the backbone of CIIR. Therefore, the sulfur cured CIIR shows inferior thermo-mechanical properties at elevated temperature. In addition to this, the vulcanization of CIIR with accelerated sulfur is limited at higher temperature due to reversion. To solve these problems, 4,4′-bis (maleimido) diphenyl methane (BMDM) was applied as a crosslinking additive along with the accelerated sulfur. The detailed curing studies have proved that the presence of BMDM greatly enhanced the rheometric torque and the reversion resistance while curing CIIR with accelerated sulfur even at higher vulcanization temperature. Moreover, the crosslinking densities of the sulfur cured CIIR have increased by 109% with the use of 1 phr BMDM and further rose to 380% with 5 phr BMDM. The improved crosslink density could enable reduction of the compression set of the sulfur cured CIIR to around 40% at 100 °C when it was vulcanized in the presence of 5 phr BMDM. The kinetic studies revealed that incorporation of this additive does not adversely affect the original vulcanization behavior of CIIR with accelerated sulfur, instead it marginally improved the speed of the vulcanization.

Elucidation of degradation kinetics of CIIR nanocomposites by varying the structure of the anchoring surfactant groups

Chlorobutyl rubber (CIIR) forms an important class of synthetic rubber with fascinating properties enabling their utility in many engineering fields as well as biomedical applications. Normally the incorporation of organically modified nano clay enhances almost all the properties of the nanocomposites. The present study focuses on the difference in thermal behaviour exhibited by the organoclays like cloisite 10A, 15A and 20A.The difference in behaviour is attributed primarily due to the difference in the type of modifier, the modifier concentration and also the orientation of the entities of the filler in the polymer. Thermal degradation of the nanocomposites were done using Coats Redfern equation.

Softening dynamics of polymer blends and composites investigated by differentia spectra of dynamic mechanical analysis

AbstractThe confinement effect on molecular motions has been widely observed in polymeric blends and composites. For polymers that have softening dynamics in glass–rubber transition region, the confinement effect can influence the molecular motions to different degrees. In this work, the differentia spectra of dynamic mechanical analysis were applied to analyze the confinement effect in butyl rubber (IIR)/ethylene‐vinyl acetate copolymer (EVA) blends, IIR/high‐density polyethylene (HDPE) blends, chlorobutyl rubber (CIIR)/polystyrene (PS) blends, IIR/silica composites, and CIIR/organophilic montmorillonite (OMMT) composites. In the differentia spectra, the confinement effect from additional components on local segment motions (LSM), sub‐Rouse modes, and Rouse modes was investigated, indicating that the effect on sub‐Rouse modes is smaller than that on Rouse modes but larger than that on LSM. Moreover, the coupling effects slightly change with introduction of the secondary components, which enables us to assume that the confinement effect has a linear relationship with the content of secondary components. Finally, it has been found that the decrease in tan δ exhibited a linear relationship with the content of secondary components.

Partial replacement of carbon black by nanoclay in butyl rubber compounds for tubeless tires

Abstract Carbon black is the typical reinforcing agent used to enhance the physico-mechanical properties of rubber compounds. 40 to 60 wt.-% of carbon black is required to achieve the desired properties for tubeless tire liners and tire tread. Fly loss of carbon black particles during fabrication directly affects the respiratory tract of the human. Carbon is a type of carcinogen that induces lungs cancer, when exposed for a certain period of time. The research work aims in minimizing the quantity of carbon black in the rubber compound and compensating the physico-mechanical properties through minimal loading of nanoclay. Butyl rubber (IIR) nanocomposites are prepared using organically modified Cloisite 30B type nanoclay and carbon black. In order to overcome the compatibility mismatch between nonpolar IIR and polar nanoclay, chlorobutyl rubber (CIIR) is used as a compatibilizer. Morphology, cure characteristics, mechanical and gas barrier properties of the prepared rubber compounds are analyzed. Faster cu...

Mixed mode morphology in elastomeric blend nanocomposites: Effect on vulcanization, thermal stability and solvent permeability

The localization of organically modified nanoclays in chlorobutyl rubber (CIIR) and natural rubber (NR) blend system was carefully studied by following the vulcanization behaviour, morphology, thermal and solvent permeation characteristics. From the vulcanization studies, it was observed that incorporation of nanoclay platelets significantly affected the viscosity and vulcanization parameters such as cure time, scorch time, rate of cure and the degree of cure. Thermal analysis pointed out that the addition of nanoclay increased the thermal stability of the elastomer blends. The morphology of the blends indicated that the nanoclay platelets were localized at the interface and in both phases (mixed mode morphology) of elastomer blends and this affected the overall properties. The transport characteristics of NR/CIIR blend nanocomposites using toluene as the solvent were also studied. The transport parameters such as the equilibrium uptake, diffusion coefficient and the rate constant have been computed. The transport characteristics have been correlated with the microstructure of the blend nanocomposites. Finally, applied the Peppas–Sahlin model to fit the experimental diffusion data and the fitting was found to be reasonably good. POLYM. COMPOS., 39:E1659–E1668, 2018. © 2017 Society of Plastics Engineers

Force variation of chlorinated butyl-rubber peeling from steel in the process of vulcanization

Vulcanization of an adhered layer with the use of low-temperature vulcanizing agents with different adhesion activities was carried out to increase the heat resistance and resistance to displacement of the adhesive tapes with different adhesive activity. It is shown that the force variation of the vulcanized adherent layer based on the chlorobutyl rubber and polymeric petroleum resin for peeling from steel depends on the measurement temperature: at 25°C, the peeling force decreases, while at 80°C it increases as compared with nonvulcanized adhesive. The observed changes are conditioned both by the increase of the cohesion strength of the adhered layer and by decrease of the elastic component in the layer peeling energy.

The Main Problems of Improvement of the Means of Individual and Collective Protection in Russia

The article is dedicated to the problems of further improvement of the Russian means of individual and collective protection and to the ways of their solution. Thus, in order to reduce the weight of the facial parts of advanced indigenous masks of respiratory protective equipment, as well as for the improvement of their appearance, it is necessary to procure from abroad or to master independently the technologies of the production of chlorobutyl rubber and volcanics. It is necessary also to acquire from abroad or to learn how to produce indigenously the special rubber processing equipment. The output of modern materials for the production of flexible facial parts, panoramic glasses and spectacles (masks) for respiratory protective equipment is impossible without the procurement from abroad or mastering independently the technologies of the synthesis of optically transparent polyurethane. The further improvement of catalysts and sorbents used in canisters for filter respirators is impossible without the development of technologies of the production of fine pored catalysts and sorbents on their basis, as well as without the recovery of indigenous base for the production of sorbents and active charcoals. The output of modern filtrating materials depends completely on the development of technologies and the equipment for the production of special laminated board and other technologies of the production of multilayered filtering materials. The development of advanced means of skin protection requires the mastering by the Russian manufacturers of technologies of obtaining of microporous, air-ermeable carbon-filled material of high quality and with reinforced physical and mechanical properties. In order to produce the lightweight isolating means of skin protection is it necessary to master technologies of the production of multilayered and armor-clad membranes with high protective and physical and mechanical properties. The problems of the development and the production of the materials for the means of collective protection are the same as for the personal respiratory protective equipment.

EPDM–chlorobutyl rubber blends in γ‐radiation and hydrocarbon environment: Mechanical, transport, and ageing behavior

ABSTRACTIn nuclear applications, ethylene propylene diene monomer (EPDM) rubber is the material of choice as gaskets and O‐rings due to its radiations resistance. In nuclear fuel reprocessing, in addition to radiation, the elastomeric components have to withstand paraffinic hydrocarbons as well. But, EPDM has poor resistance to hydrocarbons. To enhance the durability of EPDM in such environments, EPDM–chlorobutyl rubber (CIIR) blends of varying compositions were developed and characterized for mechanical, thermal, dielectric, and solvent sorption behavior. Spectroscopic and morphological analysis was used to evaluate the compatibility of blends. Due to synergistic effect, the optimal composition of blends with superior mechanical properties and solvent resistance were found to be 60% to 80% EPDM and 20% to 40% CIIR. The optimized blends were irradiated with gamma rays at cumulative doses up to 2 MGy. Based on spectroscopic, morphological, mechanical, thermogravimetric, and sorption properties, blend containing 80% EPDM was found to have superior retention of properties after irradiation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45195.

ТЕХНОЛОГИИ ПРОИЗВОДСТВА ГАЛОБУТИЛКАУЧУКОВ. ЧАСТЬ 1. ТЕХНОЛОГИЯ ГАЛОГЕНИРОВАНИЯ БУТИЛКАУЧУКА, РЕАЛИЗОВАННАЯ В ПРОМЫШЛЕННОСТИ

The review presents the scientific-technical results of the development and improvement of the halobutyl rubbers production technology implemented on a commercial scale. The author considered the variants of the production scheme and the manufacturing methods for increasing the efficiency of its certain stages. Special attention is paid to the equipment design of the stages of butyl rubber dissolution, the interaction of the resulting solution with the halogenating agent and the aqueous treatment of the reaction mixture. The paper shows the possibilities of increasing the efficiency of the process due to the application of the continuous process of butyl rubber dissolution in the hydrocarbon solvent, the creation of a turbulent mode during the rubber solution flow, and the separation of the evolved halogen hydrides from the resulting halogenated elastomer. The author discusses the results of the application of various agents for neutralizing the excess halogen and halogen hydride, the necessity to keep the medium acid value within the certain limits at this stage. The results of improving the stages of halobutyl rubbers stabilization, separation and drying are briefly described. The author mentioned the disadvantages peculiar for the traditional butyl rubber halogenation technology, including the use of a special butyl rubber brand with the high values of Mooney viscosity and unsaturation in the production of chlorobutyl rubber, the necessity of bromine recuperation from water streams of the stages of excess halogen neutralization and the washing of bromobutyl rubber solution.The paper considers the possibilities to improve current technology of large-scale production of halobutyl rubbers, to increase the economic efficiency and to mitigate the environmental risks when implementing it on a commercial scale. The list of references includes patents of the world’s leading companies – halobutyl rubbers manufacturers and the publications on the results of the research carried out by the well-known specialists in this field.

Development of chlorobutyl rubber/natural rubber nanocomposites with montmorillonite for use in the inner liner of tubeless ride tires

The aim of this work was to combine the properties of chlorobutyl rubber (CIIR) and natural rubber (NR) in a binary blend for application in the inner liner of tubeless tires, using organomodified montmorillonite (Cloisite® 15A) as filler in order to improve the barrier property of the material. The maintenance of the mechanical and barrier properties of CIIR/NR 60/40 indicated that this blend can be used in the inner liner of tubeless tires, thereby reducing the cost of the final product, since the CIIR is 80% more expensive than NR.

Hollow glass microsphere as a light‐weight composites with good gas barrier property

In many polymer applications such as inner tire liners and fuel hoses, imparting excellent gas barrier properties and light‐weight properties are of prime importance. Research into this direction have been completed based on a judicious choice of polymer type or a blend thereof and the compounding ingredients. Although butyl rubber has been the polymer of choice because of its excellent gas barrier property, yet investigations were targeted to improve these properties with further modification in the polymer type and variation in compounding ingredients. In this study, a (90:10) blend of Chlorobutyl Rubber and Epoxidized Natural Rubber by weight was used as the base. Hollow glass microsphere (HGM) at fixed concentrations were used to optimize the gas barrier and light‐weight properties. It was observed that the physical properties decrease, especially the tensile strength with increasing HGM. In this blend, HGMs were effective in imparting the best overall combination of properties. J. VINYL ADDIT. TECHNOL., 24:224–228, 2018. © 2016 Society of Plastics Engineers

Experiments and modeling of non-linear viscoelastic responses in natural rubber and chlorobutyl rubber nanocomposites

The filler–filler and rubber–filler interactions in polyisoprene (natural rubber — NR) and chlorine substituted poly isoprene–isobutyl rubber (chlorobutyl rubber — CIIR) were monitored by non-linear viscoelastic measurements (Payne effect). The experimental results have been modeled using the famous Maier–Göritz equation and by the tradition approach of Kraus theory. It was observed that the filler–filler network formation in NR/organoclay nanocomposites was very strong while the interactions in CIIR/organoclay nanocomposites were very poor. The network formation and dispersion of nanoclay platelets were observed using AFM and TEM techniques. Using the DSC technique, the effects of filler–filler and filler–polymer interactions on glass transition temperature (Tg), confinement of polymer chains (χi) and the variations in heat capacity (ΔCp) were analyzed. These analyses revealed that the nanofiller loading in rubber matrix developed a rigid amorphous region due to the confinement of polymer chains. The Tg of the natural rubber nanocomposites was increased and then decreased as the filler loading increased from 0 to 10phr. The mechanical percolation behavior of rubber nanocomposites were estimated using the Huber–Vilgis approach by calculating the excess modulus. The application of this approach pointed out to a cluster–cluster aggregation model (CCA), where space filling clusters were formed. The diffusion of liquids through the nanocomposites was carefully evaluated for explaining the nanofiller interaction with the two rubber matrices. Finally, the Kraus, Lorentz–Parks and Cunneen–Russell models were applied to quantify the degree of reinforcing action of the fillers in both elastomer matrices.