Forschung

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05. Mai. 2023 | 10:22 Uhr
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Fig. 1 Dependence of conductivity on the conductive filler content with schematic pictures of conductive filler particles ordering. A – low electrical conductivity, B – beginning of the percolation threshold region, C – high electrical conductivity.
Mechanical Deformation Dependence for Elastomers and Thermoplastics

Similarities in Stress-Strain-Curve and electrical Conductivity

Electroconductive composites were prepared using either styrene–butadiene rubber or polycaprolactone matrix with varying amounts of two grades of electroconductive carbon black. Electrical conductivity was measured during deformation and at the same time a stress-strain-curve was recorded. The dependences of electrical conductivity on deformation exhibit several extremes. All conductivity changes were interpreted in terms of either the conductive pathways destruction or the formation of new ones, Thus, electrical conductivity can be correlated with the specific features of the physical network of the reinforcing filler that affect the mechanical properties of the composite.Weiterlesen...

03. Mai. 2023 | 11:04 Uhr
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Figure 2: SANS data and the tube theory interpretation. Upper figure: data at  γ = 0 Hz; the polymer is relaxed.  Lower figure at   γ = 10 Hz; the polymer is stretched.  At  γ > 10 Hz the polymer partially returns to its relaxed state due to loss of entanglements.
Domains: Affect of molecular Weight and complex Architecture

Molecular-Scale Polymer Melts Response to shear in the linear and non-linear rheological

The molecular-level response to shear of entangled polymers at interfaces and in the bulk has been of interest to understand the non-linear rheological response of polymers. Here we focus on the molecular level response to shear strain leading non-linear rheological phenomenon, in linear and star polymers comparing the observed response to the predictions of tube theory. We used SANS measurements of the bulk polymer response to shear in Couette geometry on melts of high molecular weight mixtures of polymers extending our previous results on interfacial responses with rheoNR measurements in cone-and-plate geometry.[1, 2] further development of the theory.Weiterlesen...

03. Mai. 2023 | 10:49 Uhr
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Figure 1: Quality prediction through integrated sensor technology.
A wide range of variants of the reaction injection molding process

Influence of Process Parameters on the Curing of Polyurethanes by dielectric Measurements

The Polyurethane Reaction Injection Molding (PU RIM) process is currently still reliant on a high level of know-how, both in the case of quality deviations of the product and in the initial configuration of molds. PU manufacturing hardly uses the established sensor technologies that are common in injection molding. In a research project at the Institute for Plastics Processing (IKV), the influence of the process parameters component temperature, mold temperature, material output speed and mixing ratio on the curing behavior of compact polyurethane coating systems is being experimentally investigated by means of dielectric measurements. The results show that for all variations of the process parameters investigated, the influence on the curing reaction could be successfully detected.Weiterlesen...

25. Apr. 2023 | 08:39 Uhr
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Schematic representation of the nano-sized rubber particles with different functional groups (FM).
Silica which is activated with a silane coupling agent is widely used as a reinforcing filler for passenger car tire treads

Evaluation of the Reinforcement Mechanism of functionalized Nanoparticles in Silica loaded Rubber Compounds

The performance of nano-sized rubber particles with different functional groups was studied in a silica loaded tire tread compound. The nanoparticles contained hydroxyl-, carboxyl-, dimethyl amino-, pyridino-, or epoxy- groups. In uncured compounds the reduction of filler flocculation at 160°C was mostly pronounced by nanoparticles, which contained either carboxyl or hydroxyl groups. In vulcanizates, the best filler dispersion and the best combination of mechanical and dyn.- mechanical properties were obtained with nanoparticles with OH-groups. As the silanization of the OH-groups is much slower than that of the silanol groups the OH-groups of the nanoparticles are practically not silanized at the end of the compounding procedure.Weiterlesen...

19. Apr. 2023 | 07:29 Uhr
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LCM-3D height profile of the vulcanized S2 rods of test series V4 with different „extrusion multipliers“ in two views.
Iinvestigations into the Additive Manufacturing of an EPDM-based high-viscosity Sulfur-curable Rubber Compound

Additive Manufacturing of Rubber Parts based on low viscous Compounds using a Direct-Ink-Writing Process

This paper deals with investigations into the additive manufacturing of an EPDM-based high-viscosity sulfur-curable rubber compound. In order to make the compound processible using „Direct-Ink-Writing“, different solvent concentrations are used to reduce the compound viscosity to the limited process window. For 3D-printing process variable process parameters are used to optimize the quality of the rubber part, which is controlled by laser confocal microscope, 3D-µ-CT and physical properties. In addition, the effect of residual solvent in the polymer, respectively in the semi-finished product, affect the possible volume shrinkage caused by evaporation processes of the printed part during vulcanization.Weiterlesen...

14. Apr. 2023 | 10:22 Uhr
Kautschukballen fährt auf einem Förderband nach oben
Rubber Circularity Award

Synthos schreibt internationalen Forschungspreis aus

Die Ausschreibung von Synthos richtet sich an Wissenschaftler, die im Bereich nachhaltiger syntetischer Kautschuke, Hochleistungselastomere und/oder Reifenmischungen promovieren.Weiterlesen...

14. Apr. 2023 | 06:49 Uhr
Rote schwammähnliche Struktur des Chips (in grau) wurde mit Salzkristallen erzeugt. Die roten Mikroorganismen besiedeln sie im Labor innerhalb weniger Tage.
Licht ins Dunkel bringen

Wie ein Silikonschwamm unbekannte Bakterien aufspürt

Von unserem Darm bis hin zum Meeresgrund: Mikroorganismen bevölkern nahezu jeden Lebensraum, sei er auch noch so feindlich. Für die Biotechnologie und die Medizin birgt die Vielfalt ihrer Überlebensstrategien großes Potenzial.Weiterlesen...

03. Mär. 2023 | 09:55 Uhr
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Schwarzes Gerät mit Testring Markierung.
Humanoid robots usually lose traction in real-world environments despite the speculated stabilization offered by different controlling approaches

Effect of Rubber Elasticity on humanoid Robot Walking Stability

Walking is an inherent ability used by humans for locomotion. Human walking consists of alternating cycles of contact with the ground to avoid unbalancing that depends on a synergy between the feet muscles and joints, in addition to the texture and hardness of the foot surface.Weiterlesen...

27. Feb. 2023 | 06:20 Uhr
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Kurvendiagramm mit roter  und blauer Kurve.
Preparation of Rubber Nanocomposites as its unique Characteristics

Property Enhancement of NR/Halloysite Nanotubes Composites by Introducing dual Modification

As the performance of natural rubber (NR) and halloysite nanotube (HNT) composites is uncertain due to low compatibility between the materials, Maleated NR (MNR) is then used as a compatibilizer to encourage filler-rubber compatibility.Weiterlesen...

24. Feb. 2023 | 10:00 Uhr
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„Ziehharmonika“-Effekt bei Dehnung eines Elastomer-Streifens.
Alterungs- und Ozonschutz eine wichtige Rolle

Ozonrissbildung bei Elastomeren – Eine Übersicht

Die Ozonrissbildung von Elastomeren basiert auf der chemischen Reaktion von Ozonmolekülen mit den C=C-Doppelbindungen der Polymermatrix. Die makroskopisch erkennbare Rissbildung und das Risswachstum variieren jedoch stark mit vorliegenden Umweltbedingungen.Weiterlesen...