Elastomer Technology Research Articles

ХИМИЧЕСКАЯ ТЕХНОЛОГИЯ: ЭКСПЕРТНЫЕ ОЦЕНКИ СОВРЕМЕННОГО СОСТОЯНИЯ И НАПРАВЛЕНИЙ РАЗВИТИЯ

n the previous interrelated article “Chemical technology: key concepts and principles of system study” the problems of chemical technology were considered in the sequence of topics “Analysis of the problem of defining the concept of chemical technology”, "Key principles of studying the history of chemical technology", "Problems and principles of classification of system-forming components of chemical technology". In conclusion, the results of expert assessments of significant areas of chemical technology in the areas of their direct theoretical and practical engineering and technological activities were presented. This second final article contains additional materials of the claimed study. In conclusion, the results of a generalized analysis of the content of both articles systematized by sections: general chemical technology, chemistry and technology of polymers and elastomers, electrochemical technologies, supercritical fluid technology, plasma materials modification technologies, petrochemicals and oil refining, creation of materials for multifunctional coatings, synthesis and application of materials for electronics, interaction of chemical technology and biotechnology, agricultural chemistry and the creation of effective fertilizers, development of resource-saving environmentally friendly technologies. As a result, clarification and enrichment of the conceptual and terminological apparatus of chemical technology was identified possible areas for the development of scientific research and technological developments, obtained materials for the enrichment of chemical and technological education. In general, the presented work highlights current and promising areas of chemical technology in the range of professional activities of one of the leading universities in Russia in the field of chemical technology - Kazan National Research Technological University.

Creation of Electrically Conductive Rubbers as a Promising Area in Chemistry and Technology of Processing Elastomers

Creation of Electrically Conductive Rubbers as a Promising Area in Chemistry and Technology of Processing Elastomers

Review of Dielectric elastomer based application for Soft robotics

Soft robotics is a growing field that is getting more and more attention. Unlike traditional rigid robots, soft robots have a simpler structure and control logic, a simple electric voltage change can activate the whole control system, with the capability of carrying out more complex tasks at the same time. Dielectric elastomer is thought to be a fundamental technology advancing the development of soft robots, with the advantages of fast response, great stretch capacity as well as resilience, less weight and higher energy density. Dielectric elastomer technology has many practical applications, such as grippers, robots on ground, swimming robots, artificial body tissues and so-called artificial muscles. In this paper, we mainly introduce the state-of-art application of Dielectric elastomer in the soft robotics field and also discuss the challenges that the DE-based soft robotics are encountering.

The Morphology, Mechanical and Dynamic Properties, Fire Hazard and Toxicity of Chloroprene and Butadiene Rubber Composites Cross-Linked with Zinc.

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.

Influence of Plasma-Chemical Treatment of UHMWPE Fibers on the Physical and Mechanical Properties of PCM Based on Polyurethane

Anna DANILCHENKO Graduate student Faculty of Rubber and Elastomer Technology and Processing Technology of Synthetic Rubber Department Kazan National Research Technological University 68, Karl Marks Str., Kazan, 420015, Russia any-nyta7@mail.ru Elena A. KIYANENKO Ph.D. (in Technical Sciences) Associate Professor Faculty of Rubber and Elastomer Technology and Processing

Curing Behaviors, Mechanical and Dynamic Properties of Composites Containing Chloroprene and Butadiene Rubbers Crosslinked with Nano-Iron(III) Oxide.

This paper discusses the curing behaviors, mechanical and dynamical properties of composites containing chloroprene rubber (CR) and butadiene rubber (BR) reinforced with mineral fillers. The iron(III) oxide nanoparticles were used as a crosslinking agent of the CR/BR blends. The research aimed to evaluate the effectiveness of nano-iron(III) oxide (nano-Fe2O3) as a new crosslinking agent while producing elastomeric materials with good mechanical properties and reduced flammability. The CR/BR (chloroprene rubber/butadiene rubber) blends were filled with silicas from natural resources (chalcedony, Neuburg silica earth) or silicas used in elastomer technology in many fields (aerosil, ultrasil). The results revealed that all composites were characterized by satisfactory tensile strength, tear resistance, and high resistance to fire. The filler dispersion in the elastomer matrix was carried out by using scanning electron microscopy (SEM), while the possibility of the filler–filler or filler–rubber interaction in the designed compositions was determined using the Payne effect and the Mullins effect.

Model u prostoru problema nasleđenog sistema za podršku projektovanja i proizvodnje gumenih smeša

The fourth generation legacy system used for designing rubber compounds contains valuable information related to rules of business, knowledge, methods and results in compounding. In order to leverage the accumulated knowledge or design new applications related to compounding it is important to define a domain model based on the existing system used with remarkable success in the past twenty years. Due to the lack of both source and binary code, standard software reverse engineering methods could not be applied in this situation. In the process of manufacturing rubber products, the greatest attention is focused on a further understanding and improvement of the development of new rubber compound formulations, design technology and improvement of the existing ones. A basic problem that needs to be resolved is what kind of information is needed about a particular rubber compound. The problem of building an elastomer formulation from the ground up is complex and can easily entail thousands of choices by the compounder. This problem is not a trivial one, and it can only be resolved on the basis of available science-based elastomer technology as well as software engineering methods and models. Modelling in problem space is used as a research method in this paper. Model of problem space (MOPS) deals with creating and understanding of the problem, primarily the problem that a potential user of the system faces. The modelling output transcends both data and code and results in a suite of visual models or diagrams created with use of Unified Modelling Language (UML).

Process‐structure‐property relationship of meltblown poly (styrene–ethylene/butylene–styrene) nonwovens

AbstractWith the advance of the thermoplastic plastic elastomer (TPE) technology, there are growing interest and needs for using these materials in the meltblowing process where benefits of small fiber diameters of meltblowns can be combined with rubber‐like elastic properties of elastomers. Performances and utilities of wide ranges of meltblown products such as facemask, medical barrier, wound‐care, diaper can be drastically improved with additions of TPE. In this study, a new elastomeric meltblown fabric was successfully made with the styrene–ethylene/butylene–styrene (SEBS) block copolymer, and the relationship among structure, tensile properties, and meltblowing process parameters are studied. We found that median fiber diameter increases with the polymer mass throughout and decreases with air pressure, and fabric solidity has significantly influenced by die collector distance (DCD). The pore sizes of the fabrics are directly influenced by fiber diameters at the given DCD, but higher DCD increases the pore size due to their open structures. All SEBS nonwovens exhibit high strain at break, larger than 400%. Processing parameters significantly affect tensile properties, and this can be attributed to the fabric structure changes. The reduction of fiber diameter tends to increase the tensile strength of the fabric as it created more fiber‐to‐fiber bond points.

Effect of SILPs on the Vulcanization and Properties of Ethylene-Propylene-Diene Elastomer.

Ionic liquids (ILs) are increasingly used in elastomer technology due to unique physico-chemical properties, which are stable at the temperature of preparation and during processing of rubber compounds. The latest IL application concept is supported ionic liquid-phase (SILP) materials, where an IL film is immobilized on the solid phase. The main aim of this work was studying the influence of IL immobilized on the surface of solid supports, such as silica and carbon black, on the vulcanization process, mechanical properties, and thermal behavior of ethylene–propylene–diene (EPDM) elastomer. Application of the SILP materials enabled the control of EPDM vulcanization without deterioration of the crosslink density, damping properties, thermal stability, and resistance of the vulcanizates to thermo-oxidative aging. Slight improvements in the tensile strength and hardness of the vulcanizates were observed.

The Effects of Moisture in Metal Oxide on the Mechanical and Electric Properties of Dielectric Elastomer Composites

Dielectric elastomer (DE) technology are used in several applications for example generator, sensor and actuator. One of the major factors that limits the DE performance is premature electrical breakdown. Compositing is the example that have been reported to increase the breakdown strength. In this study polydimethylsiloxane (PDMS) film will be incorporated with two different fillers which are titanium dioxide (TiO2) and zinc oxide (ZnO). Both metal oxides will be calcined up to 300°C before they are added to the PDMS elastomer as fillers. The results show that the calcined TiO2 and ZnO that incorporated in PDMS films show significant increase of breakdown strengths. Meanwhile, the calcined TiO2 PDMS film give higher breakdown strength as comparison to the calcined ZnO counterpart.

The potential application of cereal straw as a bio-filler for elastomer composites

The purpose of this research article is to present the application possibilities of cereal straw as a functional bio-filler of elastomeric materials. The work defined the precise selection of polymeric matrixes as a base for the produced biocomposites. Applied rubbers, ethylene propylene, methylvinylsilicone, butadiene–styrene and butadiene–acrylonitrile, are materials that differ in both chemical structure and methods of cross-linking. Due to the differences in material characteristics, the composites presented specific properties, which have been confirmed by a number of research methods that determine rheometric, mechanical, dynamical–mechanical properties, damping, cross-linking density and susceptibility to simulated thermo-oxidative aging processes. Application of straw as a natural bio-fillers for different elastomers increased cross-linking densities of the composites and reduced the curing time of the mixtures. Straw vulcanizates, regardless of the polymer type and simultaneously with increasing filling degree, showed a significant increase in tear strength and hardness. Moreover, these materials showed high values of damping coefficients and satisfactory strength properties, depending on the mechanical characteristics of the rubbers used. Furthermore, biocomposites produced on the basis of ethylene propylene and silicone rubber have proven their high resistance to simulated aging processes. The use of ground straw as a never previously used filler of elastomer composites proves that it is a highly valuable additive both in economic and material aspects. Its application in elastomer technology may contribute to the management of surplus agricultural wastes while being used in materials exhibiting useful properties.

Natural Rubber Composites Filled with Crop Residues as an Alternative to Vulcanizates with Common Fillers.

This present study is focused on exploring the possibility of using agricultural waste in the form of cereal straw as an active filler of biocomposites. The effect of lignocellulosic filler addition on the multifunctional properties of natural rubber composites was investigated. The results were compared with the properties of vulcanizates containing commonly used reinforcements in elastomer technology (carbon black, silica, chalk, talc). Rubber mixtures filled with straw showed the highest torque increase during rheometric measurements, which indirectly indicated a high degree of crosslinking and hardness of composites. It was found that the effect of straw addition on vulcanization time of elastomer blends was comparable with the results obtained for other conventional fillers. Moreover, the results confirmed that novel composites based on natural rubber filled with crop residues were attractive materials owing to their capacity for the formation of “structure” in combination with a good impact on reinforcement. Vulcanizates with the addition of straw showed the best barrier properties and resistance to thermo-oxidative aging from all tested samples. Furthermore, straw-based composites demonstrated that cereal straw waste could be used as an alternative, biodegradable and eco-friendly reinforcement of natural rubber composites.

Vibration attenuation of rotor-bearing systems using smart electro-rheological elastomer supports

Nowadays, capability of safe operation sufficiently away from the critical speeds is one of the most important design requirements of rotating machineries. The focus of this paper is the application of smart electro-rheological (ER) elastomers to rotor dynamics field to reduce the vibration level of a rotor system. A Jeffcott rotor, supported via two bearings at both ends augmented with ER elastomers, is considered. A finite element approach, based on the Rayleigh beam theory, is used to model the dynamics of the system, and the proposed model accounts for the rotary inertia, gyroscopic effects and shaft’s internal damping. The ER elastomer supports are simulated with four-parameter viscoelastic model. The simulation results reveal that the use of ER elastomer in the conventional bearing supports leads to downshifting of the critical speeds and a considerable reduction in its corresponding vibration amplitude. Also, the stability limit speed of the system is improved by employing the ER elastomer technology. To extend the stability region of the rotor system to higher operating rotational speeds, a simple on–off control strategy is employed. The proposed control scheme determines the required real-time voltage to be applied at ER elastomers and guarantees low vibration amplitude over a wide frequency range. The novel idea of using ER elastomers for vibration suppression of rotor systems can be fairly extended to other applications which suffer from unwanted high amplitude vibrations.

Research on Polyurethane Elastomer Abrasion Protection for Impeller of Water Pump

The pumps used in the Guhai Pumping Irrigation Project were suffered from sediment abrasion in the long term and their flow passage components, including impellers and pump shells, were also seriously abraded, which led to common problems of poor reliability, low operation efficiency and high energy consumption in almost all the pump stations. Therefore, these problems had made these pumps unable to satisfy the requirements for construction of resource-saving society and development of hydraulic engineering modernization. The steel plate welded impeller technology was a new technique specially developed to solve the serious abrasion of pump impellers. However, the results of long-term application of this technology had demonstrated that the composite resin mortar coating had a limited capability to resist cavitation and thus the parts which are fragile to cavitation on the impellers will fall off easily, which further aggravated the impeller abrasion. After one irrigation season, there were multiple penetrated holes occurring on the impellers, which significantly affects the operation efficiency of the pumps. In order to solve the cavitation resistance issue of composite resin mortar. The polyurethane elastomer technology was developed for the first time, which the polyurethane material with the currently best performance in cavitation resistance was adopted, and the appropriate promoters were added into the polyurethane to improve its properties. In addition, high-strength binder and mechanical connection mode were developed in this technology, which greatly enhanced the binding strength between the polyurethane coating and the pump impellers. Besides, vacuum casting technique was adopted to obtain the pump impeller coating which had excellent performance in abrasion and cavitation resistance. This technology was firstly tested in the Guhai Dazhanchang Pump Station in March 2015. After one and half years operation, it is found that the coating had been improved obviously, and the pumps had long-term stable operation efficiency, which had reached the anticipated testing goal. It is provided reference for the pump stations in Yellow River Diversion Project and pump manufacturers to solve the pump impeller cavitation problem.

The morphology and structure of natural clays from Yangtze River and their interactions with polyurethane elastomer

In thermoplastic polyurethane elastomer (PUE) technology, the necessity for revealing the interactions between clays and polyurethane chains is improving recently. In this paper, three different natural clays (NC) were firstly employed to prepare NC/PUE composites to explore the relation between fillers and PUE chains. We found that the natural clays were formed from sand to fertile soil, and then corroded deeply to CaCO3 (rock) by surroundings, including water, wind and temperature and so on. Then, the neat PUE and NC/PUE composites were characterized by SEM, TEM, XRD, SAXS, FTIR and DSC to investigate the function of natural clays in polyurethane chains. We found that the different clays particles interacted with PUE chains in different ways. The lamellae and stacks of rock aggregated mainly in PUE matrix and interact with the hard/soft domains, while that of sand and soil aggregates mainly on the surface of PUE matrix.

CRITICAL VELOCITY OF CONTROLLABILITY OF SLIDING FRICTION BY NORMAL OSCILLATIONS IN VISCOELASTIC CONTACTS

Sliding friction can be reduced substantially by applying ultrasonic vibration in the sliding plane or in the normal direction. This effect is well known and used in many applications ranging from press forming to ultrasonic actuators. One of the characteristics of the phenomenon is that, at a given frequency and amplitude of oscillation, the observed friction reduction diminishes with increasing sliding velocity. Beyond a certain critical sliding velocity, there is no longer any difference between the coefficients of friction with or without vibration. This critical velocity depends on material and kinematic parameters and is a key characteristic that must be accounted for by any theory of influence of vibration on friction. Recently, the critical sliding velocity has been interpreted as the transition point from periodic stick-slip to pure sliding and was calculated for purely elastic contacts under uniform sliding with periodic normal loading. Here we perform a similar analysis of the critical velocity in viscoelastic contacts using a Kelvin material to describe viscoelasticity. A closed-form solution is presented, which contains previously reported results as special cases. This paves the way for more detailed studies of active control of friction in viscoelastic systems, a previously neglected topic with possible applications in elastomer technology and in medicine.

A Soft Jellyfish Robot Driven by a Dielectric Elastomer Actuator

Although dielectric elastomers have been extensively studied recently, to date there has been little research into application of dielectric elastomer actuators to undersea robots. This letter focuses on development of a jellyfish robot using a dielectric elastomer actuator, which exhibits muscle-like properties including large deformation and high energy density. We carry out experiments to test the actuator’s deformation and force. Theoretical simulations are conducted to analyze the performance of the actuator, which are qualitatively consistent with the experiments. The preliminary studies show that this jellyfish robot based on dielectric elastomer technology can move effectively in water. The robot also exhibits fast response and high capacity of payload (compared to its self-weight).

プリント配線板を支える高分子材料 半導体パッケージ用感光性ソルダーレジストの新展開

Photosensitive solder resist for semiconductor package is now in transition stage. Smaller flip-chip burnp and finer bump pitch lead thinner solder resist with surface flatness and uniform thickness. In addition, the thickness precision is also important in the package. The demand of film type solder resist has been increasing against conventional liquid ink type one because of its ease to give flat surface. Additional advantage of the film type solder resist is that it is easy to disperse fine particle filler and remove fine foreign matters in the varnish because of the lower viscosity of the vanish comparing with that of conventiona1 liquid ink type solder resist. The solder resist of next generation requires the following properties: (1) Compatibility with direct image exposure, (2) Thinner film, (3) Fine pitch HAST resistance (line/space ≤ 8/8 μm), and (4) Crack resistance on various heat processes and TCT. In this paper, we introduce our approaches to satisfy these requirments such as preventing oxidation of underlying Cu which weakens the resistance to plating with thin thickness, greatly reducing contamination by Cl and Br, espetially hydrolyzable Cl, for HAST, and improving crack resistance by combination of new high Tg and low CTE resin and our elastomer technology.

Effects of synthesis technology route on mechanical properties and phases/microstructures of polyurethane elastomers

In the present paper, the synthesis technology of polyurethane elastomers was studied with an aim at better controlling their phases/microstructures and properties. In particular, mechanical properties and glass transition temperatures as well as microphase separation of different polyurethane elastomers synthesised by four technology routes, with an emphasis on the effects of raw materials and their feeding sequences, were investigated using a universal testing machine, a differential scanning calorimetric (DSC) and a fourier transform infrared spectrometer (FITR). The results offered an ideal synthesis route: first diisocyanate was added into the dried polyether, then the two materials were fully reacted and finally the chain extender was added into the mixture products. The resulting polyurethane elastomer exhibited an excellent mechanical performance, a low glass transition temperature and a perfect microphase separation.

A breakthrough in MDI cast elastomer technology: Bayer MaterialScience introduces line of MDI amine-curable prepolymers

A breakthrough in MDI cast elastomer technology: Bayer MaterialScience introduces line of MDI amine-curable prepolymers