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DIK Publicly funded projects
EU Projects:
Manufacture and Characterization of Nanoparticles in the Plasma Process
Commissioned by:
European Community (GRD1-1999-10617)
Project partners:
Erachem Europa (Belg), Armines (Fra), CNRS-IMP (Fra), UCL-PCPM (Belg), SINTEF (Nor), Premix (Fin), IECB (Fra), Merk, DIK
Term:
01.04.2000 - 31.03.2003
The goal of the project was the production, characterization and investigation of the application potential of nanoscale organic fillers (fullerenes, nanotubes) in polymer composites. In alliance with industrial companies and research institutes a new technology was applied for manufacturing employing a plasma reactor. The properties of these fillers as used in rubber compounds and vulcanizates were studied, with primary interest focused on the static, dynamic and electric properties of these composites.
Interphase bonding of scrap rubber powder (TAMARREC)
Commissioned by:
European Research Coordination Agency-German Federal Environmental Protection Agency, project funded by Federal Ministry for Education and Research
Project partners:
Vredestein (NL), Technische Universität Chemnitz, DIK
Term:
01.03.1999 - 31.08.2000
The objective of the research project was to achieve an optimum interface bonding to a new elastomer matrix by means of chemical modification of the particle surface of scrap rubber powder. Within the framework of the work, wide-ranging chemical and morphological characterizations of scrap rubber powder were carried out. Tests conducted on compounds of rubber matrices and untreated rubber powder showed the mechanical property profile to be less and less favorable with increasing particle size. Modification of scrap rubber powder with maleic acid anhydride, epoxidation and hydroxylation represent highly promising approaches for realizing an optimum bond between rubber matrix and scrap rubber particle.
Development of New Rubber Compounds and Optimized Mixing and Curing Processes for Tire Manufacture
Commissioned by:
European Community (BE-6131)
Project partners:
Pirelli (Italy), Francis Shaw (UK), University of Cologne, DIK
Term:
01.11.1992 - 30.04.1997
The main goal of the project was to improve tire manufacturing productivity and the tire performance. The proposed solution consisted in reducing vulcanization cycles by raising the temperature and by using optimized compounds or formulas together with an optimized mixing procedure. The compounding behavior of silica tire compounds and the changes in nodal structures and crosslinking density resulting from altered vulcanization conditions - was studied in connection with mechanical properties.
Projects commissioned by the German Research Foundation (DFG):
SPP 1369 Priority Program: Investigations into the Polymer-Filler Interphase Dynamics of Reinforced Elastomers: Experiments, Modeling and Theory
Commissioned by:
DFG
Project partners:
Max-Planck-Institute for Polymer Research Mainz (Prof. T. A. Vilgis), DIK (PD Dr. M. Klüppel)
Term:
01.07.2008 - 30.06.2011
This project is to analyze the influence of temperature- and frequency-dependent gradients of the vitrification of polymer chains near the filler surface on the linear and non-linear viscoelastic properties of reinforced elastomers. By means of theoretical methods and experimental techniques - such as static gas adsorption, dielectric spectroscopy, dynamic-mechanical and stress-strain analysis - the study is to look at what significance filler type, concentration and surface activity (specific surface, harshness and energy distribution) have on the glass transition dynamics of elastomer composites. The objective is to arrive at a deeper understanding of the transition from polymer matrix to polymer interphase behavior near the filler surface and of the overlying filler network dynamics resulting from immobilized polymer layers between adjacent filler particles.
DFG research group on "Fracture Mechanics and Static Mechanics of Reinforced Elastomer Blends", Subproject 1: Morphology and Micromechanics
Commissioned by:
German Research Foundation (DFG) (FOR 597)
Project partners:
Institute of Polymer Research (IPF) Dresden (Prof. Heinrich), Universität Leipzig (Prof. Kaliske), Universität Halle (Prof. Grellmann), Max Planck Institute for Polymer Research Mainz (Prof. Vilgis), DIK (PD Dr. Klüppel)
Term:
01.09.2005 - 31.03.2012
The research group's goal is to formulate deductions about structural property relations in filler reinforced elastomer blends and the cross-scale modeling of reinforcement and dynamic tear propagation in nanoscale filled, multiphase elastomer systems. Subproject 1 is to clarify the connection between filler distribution across the blend phases and fracture mechanical properties. By means of dielectric relaxation spectroscopy, the influence of confinements on the vitrification dynamics of polymer chains in nanoscale filler structures it is also to analyze so as to arrive at a deeper understanding of polymer-filler and filler-filler coupling. This is to serve as the basis for further development of a micromechanical concept for the deformation mechanics of filled elastomer blends with regard to fracture mechanical properties, which concept is then to be confirmed by experimental data.
DFG research group on "Polysialic Acid: Evaluation of a New Material as Scaffold Material for the Manufacture of Artificial Tissue", Subproject 3: "Development of techniques for the production of 2D and 3D solids from polysialic acids and characterization of hierarchic self-organization structures"
Commissioned by:
German Research Foundation (DFG) (FOR 548)
Project partners:
Hannover Medical School (MHH) (Prof. Gerardy-Schahn, Prof. Grothe), Universität Hannover (Prof. Behrens, Prof. Kirschning, Prof. Scheper), DIK (Prof. Schuster)
Term:
09.07.2004 - 01.09.2011
In this project defined scaffolding materials for the regeneration of peripheral nerves are to be made from electrospun nanofibers consisting mainly of natural and chemically modified polysialic acid (polySia) in combination with other polymers. The project's main task is to study the influence of fiber morphology, orientation of the filament, the nonwoven mesh and the chemical and mechanical stability of the fibers. Within the research group a larger quantity of materials will be made available for "in vitro" and "in vivo" testing as well as for characterization.
DFG research group "Dynamic Contact Problems with Friction in the case of Elastomers"
Commissioned by:
German Research Foundation (DFG) (FOR 492)
Project partners:
Universität Hannover: Institut für Mechanik (Prof. Popp, Prof. Besdo), Mechatronik-Zentrum (Prof. Heimann), IBNM (Prof. Wriggers, Prof. Nackenhorst), DIK (PD Dr. Klüppel)
Term:
01.10.2002 - 31.09.2008
The goal of the DFG research group was to describe the friction process in the case of elastomers - chiefly tires - by means of physical concepts and engineering methods.
Subproject 1: Surface geometry and frictional contact on the microscale
The goal of this subproject was the modeling and analysis of microscopic factors of influence on the elastic contact and friction between elastomers and harsh surfaces under dynamic conditions. It elucidated the significance of the microscopic harshness of frictional surfaces for frictional contact and thus the related adhesion and friction phenomena at the macroscopic length scale. In this way it was possible to make an important contribution to the development of physically motivated material models for FE simulations of elastic contact problems with friction in the case of elastomers.
Subproject 2b: Micromechanics of Inner Friction
In this subproject models were proposed to illustrate the effect of non-linear hysteresis losses on frictional behavior, i.e. the inner friction of filler-reinforced elastomers was described by means of micromechanical concepts. To do so, a recently developed model for stress-induced breakdown of filler clusters was resorted to that allows for a well-founded description of stress softening and filler-induced hysteresis. The project focused on expanding this model with respect to time, frequency and temperature effects.
Projects Commissioned by the Federal Ministry of Education and Research (BMBF):
Energy-efficient Elastomers (ENEFEL)
Commissioned by:
Federal Ministry of Education and Research (03X0002D)
Project partners:
ContiTech AG, Evonik Degussa GmbH, IPF-Dresden, DIK
Term:
01.04.2009 - 31.03.2012
The goal of the project is the development of energy-efficient elastomer hybrid systems that exhibit longer service life and improved media-resistance (utilization of biofuels) and gas permeation values in high-temperature use. This is intended to reduce environmental pollution from other climate-relevant gases. The scientific goal is the elucidation of the connection between the surface structure and morphology of novel filler hybrid systems and their physical property profile. A deeper understanding of the physics of the structural-activity mechanisms of reinforced elastomers obtained and theoretical models also developed for explaining the structural hierarchy of reinforcement mechanisms on various length and time scales. In this way better use can be made of the synergies of polymer physics and rubber technology.
Elastomers for High-Strength Seals (CarboElast) - Subproject 18
Commissioned by:
Federal Ministry of Education and Research (03X0055C)
Project partners:
Rhein Chemie Rheinau GmbH, Freudenberg Forschungsdienste KG, DIK
Term:
01.02.2009 - 31.01.2012
The goal of the project is to greatly improve the performance spectrum of elastomers and thermoplastic elastomer materials in the area of high-performance seals by means of optimally dispersed carbon-nanotube (CNT) preparations, with aim of expanding existing applications and paving the way to novel applications fields. The focus in this case is on the optimization of mechanical-dynamic properties, ageing resistance, heat conductivity and electric properties. Of particular interest here is the high reinforcement potential to already be realized with low proportions of CNT. This potential can be exploited only in connection with a suitable method for dispersing CNTs in the rubber matrix. The activities of DIK are to be found in the manufacture of CNT compounds with select polymer systems and the characterization of these systems.
New Elastomer Products based on Nanocomposites (Nanoelastomer)
Commissioned by:
Federal Ministry of Education and Research (03X3533D)
Project partners:
Continental AG, ContiTech AG, Süd-Chemie AG, IPF-Dresden, DIK
Term:
01.07.2005 - 31.06.2008
The overriding goal of the research project consisted in the development of strategies that would allow for more targeted use of nanotechnology in the area of technical elastomer products and tires, in particular in the automotive area. Correlations were found between morphological and mechanical material performance characteristics that allow for statements on the structure-activity mechanism of nanostructured, multiphase elastomer composites. In this regard, the applicability of universal physical models of reinforcement and innovative fraction-mechanical concepts for the nanocomposites were reviewed. The complex relaxation dynamics of systems chiefly responsible for the performance features of elastomer products - wet grip and rolling resistance in the case of tires, for example - were subjected to particular analysis.
Extending the Service Life of Dynamically Stressed High-Performance Elastomers
Commissioned by:
Federal Ministry of Education and Research (01RC0135)
Project partners:
Rhein Chemie Rheinau GmbH, Vibracoustic GmbH, Freudenberg Forschungsdienste KG, Parker Hannifin GmbH, Veritas AG, Technische Universität Hamburg/Haarburg, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen, DIK
Term:
01.07.2001 - 30.09.2005
Ageing processes triggered by mechanical stress, ambient media and environmental exposure limit the service life and durability of elastomer components. The goal of this project, in which an alliance of industrial companies and research institutes participated, was thus to arrive at a better understanding of the thermomechanical wear and ageing mechanisms of elastomers and to better describe the influence of ageing on chemical and physical properties. The knowledge gained flowed directly into the industrial manufacturing process, making a considerable contribution to an improvement in material properties and an extension of the service life of elastomer products.
Supramolecularly Structured Elastomer Composites with Adaptive Energy Dissipation
Commissioned by:
Federal Ministry of Education and Research
Project partners:
Universität Bayreuth, Max Planck Institute for Polymer Research Mainz, DIK
Term:
01.07.2001 - 31.12.2002
The goal of the project was to manufacture supramolecularly structured elastomer composites with an optimized viscoelastic property profile. The research project thus focused on the synthesis of innovative rubber types and polymer fillers that make possible adaptive coupling between polymer chains and/or filler surface. Alongside this, a fundamental description of polymer-filler interaction in nanoscale porous filler structures on the basis of a physical model developed specifically for this purpose was applied. The results show that the structure-property relationships of reinforced elastomers can be checked and controlled via chemical and physical interaction parameters.
Hyperelastic Networks by Means of Supramolecular Structuring of Functional Lattices FSS 05 - Subproject B
Commissioned by:
Federal Ministry of Education and Research (03D0044C8)
Project partners:
Bayer AG, Continental AG, Universität Halle, DIK
Term:
01.01.1996 - 31.12.1998
In the case of compartmented, supramolecularly structured systems composed of functionalized lattices, the strategy of morphology adjustment consists in making targeted and energy-efficient use of prefabricated compartments in the mixing process to generate a time- and process-invariant morphology. Core goals of the subproject were thus the characterization of the mechanical property profile of generated hyperelastic networks as well as the characterization of morphology. Within the framework of the project, a biaxial elongation-jump method was developed that allows for permanent measurements of the modulus of rigidity while also normally allowing for elongations. Indirectly this method can be used to detect changes in material structure that, on the basis of structural data, open the way to a deeper understanding of the structural property relationships of the new hyperelastic materials developed within the framework of the overall project.
Projects Commissioned by the German Federation of Industrial Research Associations (AiF: Arbeitsgemeinschaft industrielle Forschung):
Avoidance of Stick-Slip Frictional Instabilities of Coated Elastomers on Microscopically Harsh and Smooth Surfaces
Commissioned by:
German Federation of Industrial Research Associations (AiF 15810 BG)
Project partners:
Research Institute of Leather and Plastic Sheeting (FILK), DIK
Term:
01.01.2008 - 30.09.2010
The goal of the research project is the experimental analysis and modeling of different factors influencing the elastic contact and the friction of sliding-lacquer-coated elastomers with microscopically harsh to smooth, rigid surfaces. The significance of the viscoelasticity and surface energy of the friction partners and of the microscopic coarseness of the friction surfaces for the friction contact is to be elucidated to allow for a presentation of the related adhesion and hysteresis phenomena at the macroscopic length scale. The influence of coating morphology and coating chemistry and of the roughness of the friction partner on stick-slip-friction instabilities is, moreover, also to be analyzed. This is to contribute to a better understanding of adhesive and dynamic friction in the case of polymer materials so as to allow for a suppression of annoying noise build-up and a minimization of component and semifinished material wear due to abrasion and fatigue.
Damage Mechanisms in Rubber Materials
Commissioned by:
German Federation of Industrial Research Associations (AiF 15694N)
Project partners:
-
Term:
01.07.2008 - 31.12.2010
The overriding goal of the research project is the identification of optimization criteria in terms of fatigue and damage in the course of material development and material selection and in component design and dimensioning. A further objective was to achieve a marked improvement in the hitherto unsatisfactory degree of precision in service life predictions. Both are to be realized by means of detailed characterization of the micro- and macroscale structures of elastomer materials and the elucidation of fatigue- and damage-relevant mechanisms.
Reduction in Friction and Wear in the Case of Plastic or Rubber Technical Components Achieved through Surface Refinement by means of the Sol-Gel Technique
Commissioned by:
German Federation of Industrial Research Associations (AiF 196 ZN)
Project partners:
Chair of Textile Chemistry and Macromolecular Chemistry (DWI) at RWTH Aachen University, Institute of Polymer Technology (LKT) at University of Erlangen-Nürnberg, DIK
Term:
01.02.2006 - 31.01.2009
Within the framework of the research project, basic insights were acquired into the application potential of nanoparticles in reducing friction and wear in polymer materials. In this way a scientific basis could be created for material design and for the manufacture of innovative products of practical use in industry in responding to the growing demand for lightweight, ultra-heavy-duty components. This opened the way to a new material class with improved friction and wear properties boasting not only positive performance features but also high price efficiency.
Nanotechnological Modification of Elastomer Surfaces
Commissioned by:
German Federation of Industrial Research Associations (AiF 15393 BG)
Project partners:
Research Institute of Leather and Plastic Sheeting (FILK), DIK
Term:
01.11.2007 - 31.12.2009
New active interfaces are to be developed by means of dry-chemical modification of elastomer surfaces with different plasma variants. These interfaces will yield expanded component functionality under equipment conditions suitable for practical applications. The functionalization should lead to elimination of the problems of elastomer surface printability and bondability. At the same time the adhesive hold typical of this polymer class, resulting from high stiction and dynamic friction, is to be eliminated. Another intended research focal point is the application of polymer layers by means of plasma polymerization to generate barriers that act against fluid and gas permeation and diffusion and/or to increase resistance to aggressive "environmental influences". It is important that the modification processes on the rubber surface does not alter the properties of the rubber matrix.
Sealing Ageing in Synthetic Transmission Oils
Commissioned by:
German Federation of Industrial Research Associations
Project partners:
IMKT (Universität Hannover), DIK
Term:
01.08.2006 - 31.07.2008
The goal of the project was to determine the application limits of different elastomer seal materials in combination with various synthetic oils by employing a new testing method. The method involves the ageing of the elastomer specimen in a tempered oil bath and determination of the physical measurands at regular intervals. This presents a nondestructive, nonlengthy possibility for studying the mechanical property changes that the elastomer undergoes on exposure to oil without having to remove the specimen from the oil bath.
Sealing Compatibility of Synthetic Oils, Including Eco-Friendly Ester Lubricants
Commissioned by:
German Federation of Industrial Research Associations
Project partners:
IMKT (Universität Hannover), DIK
Term:
01.09.2002 - 28.02.2005
Within the framework of this project the resistance of seals to synthetic oils was studied. The results of this study make it possible for the user of synthetic oils to select seals made of suitable elastomer materials and, in this way, to avoid premature malfunction. By means of chemical analysis, damage and ageing mechanisms of the specimens were characterized. On this basis improvements can be effected in the elastomers and synthetic oils studied. In addition, a less costly and faster test method for predicting the operativeness of seals with various lubricants was developed.
Control of Compounding State and Material Properties by Means of Targeted Compounding Methods
Commissioned by:
German Federation of Industrial Research Associations (AiF 13218 N)
Project partners:
-
Term:
01.05.2002 - 31.10.2004
An analysis of phase morphology and filler distribution in multiphase rubber blends served as the basis for studying the influence that the compound state generated under defined process conditions has on the mechanical property profile. Interconnections were established in the sequence formula - compounding method - compound state and material properties. These allow for control of material properties by means of targeted alteration in compounding technology (predictive mixing). Strategies were also developed that pave the way to reproducibly manufacturing the compound state aimed at in multiphase blends. In this way it was possible to contribute to quality-oriented and cost-efficient production of high-performance elastomer composite materials.
Federal State of Lower Saxony - Volkswagen Foundation:
Innovative Hybrid Elastomers with high Wear Resistance, Good Oil Resistance and Anisotropic Properties
Commissioned by:
Investitions- und Förderbank Niedersachsen - NBank
Project partners:
-
Term:
18.02.2008 - 30.06.2011
Elastomers are used to manufacture road, rail and air transport safety components subject to extreme mechanical-dynamic stress. When in use, such components are frequently exposed to aggressive media like mineral oils, fuels and gases. The elastomer materials currently available are not always up to adequately meeting these demands. The goal of this project is thus to develop wear-proof hybrid elastomers, with the hybrid component consisting [? Verb fehlte in der Vorlage] of a functional nanoscale filler. The project specifically tracks the manufacture and characterization of hybrid elastomers containing fibers and particles.
Functionalization of Nanoparticles for Innovative Plastic Products
Commissioned by:
Investitions- und Förderbank Niedersachsen - NBank (W3-80019725)
Project partners:
Laser Zentrum Hannover e.V., DIK
Term:
28.12.2007 - 31.03.2010
Within the framework of a joint project, nanoparticles (e.g. silver, copper, alloys) are directly manufactured by means of laser beam removal in solvents or monomer solutions. The goal of the project consists in systematic studies of stabilization of the nanoparticles generated by means of laser beam removal and the subsequent embedding of the nanoparticles in different polymer systems, with the removal trials being conducted in a specially designed removal chamber and the nanocomposites studied with respect to their properties.
Manufacture of Nanofibers by Means of Electrospinning for the Production of Elastomer Components with Adaptive Properties
Commissioned by:
Investitions- und Förderbank Niedersachsen - NBank
Project partners:
NICAS (Israel), DIK
Term:
01.07.2007 - 31.06.2009
Materials with properties capable of adapting to stimuli harbor high development potential. Chief among these, elastomer-based nano-composites have good prospects for success. This new material concept includes anisotropically structured high-performance components, which are to be manufactured using nanofibers. The diameter of the nanofibers is as much as two magnitudes below that of conventional industrial fibers. Within the framework of a cooperative arrangement with an Israeli high-tech partner (NICAS), new fibers of different composition, mechanical strength, thermal and electrical conductivity and, under circumstances, magnetic properties are to be manufactured from different polymers by means of electrospinning.
Elastic-Turbulent Flow Characteristics of Polymer Solutions and Polymer Melts
Commissioned by:
Ministry for Science and Culture of Lower Saxony/ Volkswagen Foundation (VW-ZN2189)
Project partners:
Weizmann Institute (Israel), DIK
Term:
01.01. 2007 - 31.12.2009
The goal of the project is to obtain a deeper understanding of the physics of flow anomalies in the case of rubber extrusion - here especially melt fracture. For this purpose the transition in the case of polymer solutions and melts from laminary flow to elastically turbulent flow is to be studied. Of considerable interest from a scientific perspective is the question of whether this cross-over adheres to the same regularities as the transition of various hydrodynamic, electric and acoustic processes from ordered to chaotic behavior. By means of characteristic bifurcations (doubling of periodicity) as per the universal Feigenbaum constants delta = 4,6692, these processes can be described in a uniform universality class.
Projects commissioned by DKG:
Investigations of the Influence of Light-Colored Fillers and Additives on the Chain Dynamics of Elastomers by Means of Relaxation Time in Nuclear Magnetic Resonance (NMR)
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
15.09.2009 - 31.06.2011
The properties of elastomers are determined by the type of rubber matrix and its chain mobility, by additives and their concentration - especially plasticizers - and to a large extent by fillers, alongside chemical crosslinking. The objective of the research project is to make a contribution to the characterization of plasticizer/polymer interactions and polymer/filler interactions of light-filled compounds, taking into special account layer silicates. For this purpose, measurements of polymer chain mobility are to be taken at a high-frequency-range (15 MHZ) with the help of NMR relaxation time measuring methods. At the same time, the NMR relaxation time measuring method is to be studied for its suitability as fast, correct and precise characterization of filler dispersion and plasticizer efficiency. The results are to contribute to the development of elastomers with improved dynamic properties and to serve the purpose of optimizing quality assurance methods.
Manufacture and Characterization of Nanofibers for Reinforcement of Micro Components by Means of Electrospinning
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.06.2008 - 30.05.2011
Proceeding on the knowledge that the advantageous properties of composite materials can be increased by means of matrix-filler interaction and the respective phase interface, the commissioned research project is to study the reinforcement effect achieved by nanofibers with a high specific surface. Nanofibers are to be made by electrospinning, for which purpose semi-crystalline thermoplastics of varying polarity and mechanical strength are to be used (PP, PET, nylon-6, PAN and PBI).
Development and Characterization of Nano- and Microcomposites with High Permeation Density
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.07.2007 - 30.06.2010
The goal of the project is the manufacture of nano- and microcomposites with the greatest possible permeation density by means of two different processes and a subsequent characterization of the products. In one case layer silicates are to be introduced into rubber lattices by "dynamic" co-coagulation. In the other process, composite materials are made by mechanically mixing thin plates of glass with high aspect ratio into the same rubber types. On the basis of the morphological characteristics determined in this way, model conceptions are to be designed that describe the specific differences in the mass transfer in nano- and microcomposites.
Investigation into the Consumption of p-Phenylene Diamines in Thermal-Oxidative Ageing Processes
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
Term:
01.09.2007 - 31.08.2010
This research project is to contribute to an understanding of the activity mechanism of anti-oxidants - and specifically of the technically significant p-phenylene diamines (PPDe) - under thermal-oxidative conditions, with primary focus on the study of the chemical processes involved in oxidation protection and on the kinetics of the reaction of anti-oxidants with oxygen. The substituent influence (structure-activity relationship) on the reactivity of the PPDe is also a partial aspect in all of this. The extent to which oxidation protection can be provided by already oxidized p-phenylene diamines is also to be elucidated.
Development and Characterization of Nano- and Microcomposites with High Permeation Density
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
Term:
01.07.2007 - 30.06.2009
Polymer materials with good barrier properties are increasingly required for thermoplastic structural elements and elastomer components to ensure minimal emissions despite higher output and longer service life. Corresponding elastomer composites are developed above all from impermeable rubbers in combination with fillers that lengthen the diffusion path. Natural layer silicates (smectites) and thin glass platelets with high aspect ratios have shown themselves to be particularly promising. Special value was attached to integration, with the aim of particle orientation.
Service Life Prediction of Multiaxially Stressed Elastomer Components
Commissioned by:
Deutsche Kautschukgesellschaft e.V.
Project partners:
-
Term:
01.08.2007 - 31.07.2009
The goal of the research project was the identification of the characteristic deterioration values determining the endurance strength of technical rubber materials and the full exploitation of the considerable potential this allows - already in the conception and design phase - for upping the cost-efficiency of the components. The characteristic values cover the effects of loads, both those of varying intensity as well as those in varying directions. For the detailed investigation of the directional influence and multiaxial load conditions, a novel test unit was created and successfully employed for realizing simple shear stress with rotating axes.
Manufacture and Properties of Nanostructured Composite Materials Made of Polar Rubber Lattices and Biologically Nanofibers Formed "in-situ"
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.07.2006 - 30.06.2009
The goal of the work was the manufacture of nanocomposites from organic fibers and layer silicates and rubber to expand the application spectrum of elastomer materials. The project focused on optimizing material and process-related parameters and their influence both on filler morphology and on the mechanical properties of composite materials. The rheological properties of the composites obtained were, moreover, tested while they were in a non-crosslinked state and their mechanical properties tested after they had been vulcanized.
Investigation of Polymer Dynamics in the High-Frequency Range as a Function of the Constitution and Structure of the Rubber Types
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.07.2006 - 30.06.2009
(T. Alshuth)
Development of Magnetic Elastomers with Anisotropic and Adaptive Properties
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.07.2006 - 31.12.2008
(T. Alshuth)
Investigation of Thermal and Oxidative Damage to Elastomers by Means of Chemiluminescence
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.07.2005 - 31.01.2008
The service life of elastomers is largely determined by irreversible thermal-oxidative ageing processes. The essential goal of the project is thus to contribute to a greater understanding of the mechanisms at work by application of chemiluminescence method (CL). Specifically the following aspects were studied: validation of the CL method; the influence of polymer constitution and configuration on ageing stability; the effectiveness of antioxidants as a function of their molecular structure; the influence of fillers, crosslinking and processing on ageing behavior. Chemiluminescence is a highly promising method for shortening the time required for characterization of oxidative ageing and for investigation of kinetic and mechanistic aspects, especially in the case of appropriate specimen conditioning and in conjunction with other analytic methods, such as, for example, FT-IR spectroscopy.
Impermeability of Elastomers
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.07.2004 - 30.06.2007
The goal of the project was to investigate material influence parameters such as polymer selection, crosslinking density, the selection of fillers and filler content on the impermeability of elastomer components. As part of this work, a measuring apparatus for quantitative characterization of permeation and diffusion processes was developed and optimized on the basis of a dynamic measuring principle. With the help of this apparatus, the diffusion coefficients and permeation rates of fuel components were analyzed for different elastomers, varying the aforementioned parameters, as well as for blends.
Dynamic Co-Coagulation of Cellulose in Rubber Matrices
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.07.2003 - 31.01.2006
The goal of the project was to manufacture reinforced nano-composite materials by means of dynamic co-coagulation of rubber latex and cellulose xanthate. This was realized with the help of an apparatus created specifically for this purpose, in which the components were guided into a flow reactor by means of inert gas overpressure and precipitated there with acid in a shear flow. The dynamic co-coagulation process occurs continuously in one stage. Cellulose nanofibers are generated "in-situ" and optimally embedded in rubber. Thanks to its enlarged specific surface, the nanofibers of the regenerated cellulose (cellulose 2) make possible a quantitative improvement in the interaction with the surrounding polymer matrix. Cellulose is different from carbon black and other classic fillers in that even minimal concentrations of it can have a major effect on the composites' mechanical properties profile, impermeability and swelling.
Chemical Investigations into the Fatigue Behavior of Sulfur-Crosslinked Elastomers
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.07.2002 - 30.06.2004
In the project chemical reactions with sulfur-crosslinked elastomers were investigated, primarily in respect of crosslinking density and nodal structures, and with polymers, primarily with a view to mechanical and, especially, mechanical-dynamic stress. The contribution of oxidatively or mechanically initiated radical chemical reactions with polymer, resulting in additional crosslinking or chain degradation, was studied as a function of the polymer and its microstructure. Elastomers with a styrene butadiene rubber base (SBRs), nitrile butadiene rubber (NBRs) and EPDM as saturated polymer were used as representative materials. In the case of CV systems (high sulfur/accelerator ratio), for example, a dynamic load tends to give rise to an increase in network strand density. This effect is more pronounced for SBR rubber types of a high vinyl content, which is then also reflected in the mechanical value levels of elongation at tear and resistance to tear.
Characterization of the Surface Activity of Silicic Acids and Special Carbon Blacks by Means of Static and Dynamic Gas Adsorption
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.06.2001 - 31.12. 2004
The goal of the project was to characterize the surface activity of reinforcing fillers and their effects on rubber-filler interaction. Quite specifically, chemically modified carbon blacks and silicic acids were studied by means of static and dynamic gas adsorption. It was possible to demonstrate that surface modification - graphitization in the case of carbon blacks, for example - constitutes a significant intervention in interparticle interaction, with dispersion improving as a consequence of the change in surface potential, while the filler network is weakened and hysteresis reduced.
Studies into the Effect of the Interphase and the Phase Network in Dynamically Loaded Elastomer Blends
Commissioned by:
Deutsche Kautschukgesellschaft (DKG Project 14/01)
Project partners:
Term:
01.07.2001 - 31.12.2003
The goal of the research project was to obtain a deeper understanding of the physics involved in the mechanical effect of the interphase and the phase network in dynamically stressed elastomer composite materials. To this end, the bonding of the phases on nanoscopic length scales and the phase network structure in the mesoscopic length scale range were characterized in the case of unfilled blends, with special consideration being given to the influence of polymer compatibility and crosslinking. From another angle, it was possible to elucidate the effect of fillers on the resulting phase morphology.
Development and Validation of a Micromechanical Material Model for FE Simulations of Stress-induced Softening
Commissioned by:
Deutsche Kautschukgesellschaft (DKG 8/99)
Project partners:
-
Term:
01.07.1999 - 31.12.2001
The goal of the project was to further develop a micromechanical concept for reinforcing elastomers by means of filler clusters, with the concept describing elasticity up to major elongations as well as the characteristic stress-induced softening in the case of complex three-dimensional deformations. The model was formulated in constitutive form with respect to finite element (FE) simulations of elastomer components for multiaxial states of strain. In industrial applications there continues to be a great demand for sufficiently exact, physically motivated material models, as development and testing methods increasingly rely on FE simulation as a means of cutting costs.
Investigations into the Formation of N-Nitrosamines in the Gas Phase and in Rubber Compounds under Real-Life Conditions
Commissioned by:
Deutsche Kautschuk-Gesellschaft e.V.
Project partners:
-
Term:
01.09.1993 - 28.02.1995
The work was prompted by incidents of the formation of N-nitrosamines classed as carcinogenic from reaction products of secondary amines occurring as reaction products of select accelerators, in particular from the thiuram and dithiocarbamate groups. The goal of the project was to characterize the kinetics of the nitrosation reaction of N,N-dialkylamines from nitric oxide in the gas phase but also in the rubber matrix so as to be able to better evaluate and reduce the air-borne workplace exposition.
The transformation of the dialkylamines occurs spontaneously at a high speed of reaction as a function of alkyl residue. In the rubber matrix, on the other hand, the desorption-adsorption equilibrium on the filler surface is of crucial significance for nitric oxide as well as for the previous history of the filler in terms of its adsorbed nitric oxide content.
Miscellaneously Commissioned Projects:
Sampling and Chemical Analysis of Gases and Vapors in the Manufacture and Warehousing of Rubber Products at the Plant
Commissioned by:
BG-Chemie, Heidelberg
Project partners:
BG-Chemie, Continental AG, Phoenix AG, Meteor Gummiwerke, DIK
Term:
1990 - 1996
In accordance with Section 18 of the Ordinance on Hazardous Substances, and taking into account the limit value list (Technical Rule for Hazardous Substances (TRGS) 900) for workplaces and for maximum allowable concentration values and technical occupational exposure limits (TRK values), the employer is obliged to control, reduce and avoid the exposure of employees to critical substances. Against this background, the extremely complex composition of emissions and especially of vulcanization fumes in the rubber industry, particularly in the areas of mixing, extruding, vulcanization and warehousing, makes it necessary, to have a validated and reliable sampling and analysis procedure for recording all substances judged to be toxicological that can be expected to occur in the air - in gaseous or aerosol form - in rubber industry plants. In the project, a locally deployable sampling procedure and a sampling apparatus were developed, which latter functions on the basis of active air sampling with selective accumulation (adsorption, absorption, filter) of individual substances and substance groups. The samples are analyzed and prepared centrally in the laboratory under application of essentially ultra-sensitive chromatographic (GC-MS, GC-NPD, GC-FPD, HPLC-UV) and FT-IR spectrometric methods. An important result of the project is a pooling of data on recovery rate, selectivity and application area. This serves to document the validity of the process, which was successfully tested in three stages: first in lab scale via, then in technical center scale, and finally "on-site" measurements on the shop floor.
Contamination of Masonry and Structural Elements by N-Nitrosamines - Reduction in N-Nitrosamine Emissions
Commissioned by:
BG-Chemie, Hamburg
Project partners:
-
Term:
1998 - 1999
A years-long exposure of buildings to N-nitrosamine-polluted atmosphere leads to an accumulation of this substance in walls, ceilings, floors and clothing. In line with the adsorption/desorption equilibrium between the solid "wall" phase and the atmosphere. A certain concentration of carcinogenic-grade nitrosamines - often of a critical magnitude - remains in the ambient air even when the exposure is no longer present. In the course of developing a coating (barrier layer) of the most universal possible application for use on contaminated structural elements and walls, the effectiveness of select color coating systems was investigated in laboratory testing. The approach taken was to test emissions behavior through the application of discontinuous and dynamic vaporization tests of contaminated masonry specimens (concrete, bricks and aerated concrete) before and after coating. The gas phase nitrosamines were sampled and analyzed analogous to ZH1/120.23. The only component that proved effective as barrier was a stripping agent in combination with other coating components. The effectiveness of the alkaline stripping agent can be traced to the high diffusion tightness of silicates and water glass (sodium silicate).
Systematic Investigations into the Composition of Exhaust Gases during Vulcanization
Commissioned by:
Trade Association of the German Rubber Industry (WdK), Frankfurt
Project partners:
WDK, DIK
Term:
1988 - 1995
The emission potential of elastomer materials is determined not only by the original substances in the compound's generally complex formula but also stems in large part from the primary and secondary products released by the vulcanization reaction. With the help of systematic lab investigations, the composition of vulcanization fumes was determined as a function of the formulas used and the vulcanization conditions. An essential goal - and one that was achieved - was a trace-back of the volatile substances released to ingredients in the formula. On this basis, the project developed, on the one hand, a substance list that acted as a data pooling, assigning individual substances to their origin and, on the other hand, a method suitable for routine systematic analysis.
Emissions of Scrap Rubber from Car Tires into Water in the Case of Landfilling
Commissioned by:
Gesellschaft für Altgummisysteme GmbH, Trade Association of the German Rubber Industry (WdK), Frankfurt
Project partners:
WDK, DIK
Term:
1993 - 1999
From the perspective of scrap rubber eco-friendliness, tire landfilling raises the question of groundwater contamination. The approach taken in this project consisted essentially in the development and optimization of an analytic method for identification and quantification of elutable substances - a standard car tread vulcanizate, for instance - and the implementation of storage tests with scrap tires in water.
Alongside numerous hydrocarbons from plasticizer oil and from antioxidants - IPPD, for instance - typical accelerator reaction products were also identified and their temporary elution behavior investigated as a function of pH value.
Systematic Investigations of Fumes from Elastomers and Their Raw Materials
Commissioned by:
Trade Association of the German Rubber Industry (WdK), Frankfurt
Project partners:
WDK, DIK
Term:
1996 - 2000
The statutory order on hazardous incidents requires that industry make available information on potential risks in conjunction with hazardous incidents - fires, for instance. This being the case, the project conducted systematic laboratory tests on the qualitative and, in some cases, quantitative composition of fumes emitted by raw materials - especially types of rubber, compounds and vulcanizates - as a function of different fire conditions. Ventilation and temperature were controlled with the help of a VCI apparatus [VCI = Association of the Chemical Industry]. The fire gases, obtained by adsorptive sampling, were analyzed mainly by means of GC-MS. The formation of polymer monomers and oligomers and of oxidation and pyrolysis products was correlated via the O2/CO and CO2 ratio (degree of burnout or l factor). The temperature and ventilation conditions for the preferred formation of the aforementioned substances and those from the polycyclical aromatics and other toxicologically critical substances were determined in corresponding fashion.
Autohesion in the Case of Rubber Types Used in Tires and Compound Mass and Parameters
Commissioned by:
Trade Association of the German Rubber Industry (WdK), Frankfurt
Project partners:
WDK, DIK
Term:
1996 - 2000
In the manufacture of complex elastomer products - tires, for example - special importance is accorded the assembly of non-crosslinked blanks consisting of several prefabricated semifinished products. The cohesion, and above all the dimensional stability of the "green" blank, is determined by the adhesion of the semifinished products. Methods for improving compound tackiness - like surface treatment and the use of tackifiers in compounds - are largely based on empirical experience and have been little understood to date. These interrelationships prompted systematic investigations into the autohesion of rubber types and rubber compounds, with a measuring method and apparatus suitable for highlighting scientific and practice-relevant aspects being developed.
Optimization of the Gas Permeability of Halobutyl Blends through the Compounding Method
Commissioned by:
Trade Association of the German Rubber Industry (WDK), Frankfurt
Project partners:
WDK, DIK
Term:
1996 - 1997
The basic polymers of gas impermeable elastomers - tire inner liners, for example - are halobutyl or butyl rubbers. In principle they satisfy the technical requirements very well. For economic reasons, however, there is interest in using blends with less costly polymers - NR or EPDM, for instance. With the help of a special gas permeation apparatus developed in the course of the project, variables influencing the gas tightness of elastomers were studied. These include molecular mass, blend ratio, blend morphology, the viscosity ratio of the polymers at outset, crosslinking density and the type and concentration of fillers, as well as their distribution and dispersion.
Emissions from Properly Used Tires
Commissioned by:
Office of the Environment University Dortmund
Project partners:
University Dortmund-INFU, DIK
Term:
01.04.1996 - 31.09.1997
Properly used truck and car tires can potentially release tire ingredients into the environment as a result of abrasion and elution. A goal of this project was to determine the environmental exposure of tire ingredients. This was approached from two angles. For one, synthetically manufactured tire abrasion materials and whole tires were characterized in the laboratory with respect to their potential for eluting low-molecular tire ingredients (additives) in water. From another angle, soil specimens, road drainage water and snow specimens were analyzed for tire ingredients, with the focus directed primarily at anti-oxidants and reaction products from crosslinking chemicals.
Influence of Chemical Modification on the Ultimate Properties of Polydienes
Commissioned by:
German Academic Exchange Service (DAAD) (grant)
Project partners:
-
Term:
01.04.2001 - 31.03.2003
Elastomers are materials that, by a combination of a suitable raw material selection in the formula and optimum processing, can be tailored to exhibit a desired property profile. The polymer is an extremely important compound ingredient in this regard. The characteristics of a polymer depend, in effect, essentially on its micro and macrostructure (constituent groups). An understanding of the structure-property relationships of polymers is therefore the basis for optimum polymer selection. Certain chemical modifications are ideally suited to achieving targeted changes in the property profile of existing polymers. These include epoxidation, treatment with maleic acid, or sulphonation, carried out, in this case, on SBR and BR rubber types. The modification of the polymer chains leads to restricted chain mobility, to an increase in polymer polarity and intermolecular polymer-polymer interactions, to an increase in the glass transition temperature and polymer chain relaxation time, and to higher resistance to mineral oils.
Contact partner at DIK:
Prof. Dr. Ulrich Giese
Anfragen an Webmaster @ DIKautschuk.de
Ursprungsadresse der DIK-Homepage: www.DIKautschuk.de
