NANOMECHANICS OF THE RUBBER–FILLER INTERFACE

2017 ◽  
Vol 90 (2) ◽  
pp. 272-284 ◽  
Author(s):  
Ken Nakajima ◽  
Makiko Ito ◽  
Hung Kim Nguyen ◽  
Xiaobin Liang
Keyword(s):  
Structural Information ◽  
Relaxation Modulus ◽  
Rubber Matrix ◽  
Interfacial Region ◽  
Segmental Dynamics ◽  
Static Modulus ◽  
Atomic Force ◽  
Property Evaluation ◽  
The Difference ◽  
Rubber Filler

ABSTRACT Atomic force microscope (AFM)–based nanomechanics is one of the most promising tools for accessing the rubber–filler interface while providing not only structural information but also mechanical–property evaluation. An AFM-based static modulus map is used to close in on the understanding of the filler reinforcement effect. As an example, a famous Guth–Gold equation is verified by comparing tensile testing and AFM. Two different novel methods are also introduced to visualize viscoelastic quantities such as storage and loss moduli, loss tangent, relaxation modulus, and viscosity. The difference in segmental dynamics between a rubber matrix and an interfacial region will be reviewed.

INFLUENCE OF MASTICATION ON THE MICROSTRUCTURE AND PHYSICAL PROPERTIES OF RUBBER

2021 ◽  
Author(s):  
Koji Okamoto ◽  
Michiharu Toh ◽  
Xiaobin Liang ◽  
Ken Nakajima
Keyword(s):  
Physical Properties ◽  
Elastic Moduli ◽  
Large Diameter ◽  
The Other ◽  
Rubber Matrix ◽  
Interfacial Region ◽  
Rubber Compound ◽  
Atomic Force ◽  
Rubber Compounds ◽  
Isoprene Rubber

ABSTRACT The effects of the masticated state of isoprene rubber (IR) at the carbon black (CB) addition stage on subsequent mixing, microstructure, and physical properties in the case of a kneader with a characteristic large-diameter shaft are investigated by examining the mastication-time dependence. A sufficiently masticated IR shows a shorter black incorporation time, which results in an improved dispersion of CB and better physical properties. Observing the microstructure of a rubber compound using the atomic force microscope–based nanomechanical technique, poor CB dispersion is revealed for insufficient mastication. Specifically, large CB agglomerations surrounded by the interfacial rubber region with higher elastic modulus than that of a rubber matrix are formed. Such a large CB agglomeration, on the other hand, does not appear in rubber compounds with longer mastication times. The thickness of the interfacial region becomes shorter in these cases. These observations are further discussed by the concept of “rheological unit” introduced by Mooney et al. This study demonstrates that the microstructure of a rubber compound is highly heterogenous with rubber regions of different microscopic elastic moduli and that the microstructure has an influence on CB dispersion and the physical properties of rubber.

The Reactive Formation of Diblock Copolymer at a Polymer/Polymer Interface and its Effect on Interfacial Structure

2000 ◽  
Vol 629 ◽  
Author(s):  
Jonathan S. Schulze ◽  
Timothy P. Lodge ◽  
Christopher W. Macosko
Keyword(s):  
Molecular Weight ◽  
Interfacial Structure ◽  
Root Mean Square Roughness ◽  
Radius Of Gyration ◽  
Interfacial Region ◽  
Force Microscopy ◽  
Amino Terminal ◽  
Polymer Interface ◽  
Atomic Force ◽  
Time Required

ABSTRACTThe reaction of perdeuterated amino-terminal polystyrene (dPS-NH2) with anhydrideterminal poly(methyl methacrylate) (PMMA-anh) at a PS/PMMA interface has been observed with forward recoil spectrometry (FRES). Bilayer samples were constructed by placing thin films of PS containing ∼8.5 wt % dPS-NH2 on a PMMA-anh layer. Significant reaction was observed only after annealing the samples at 174°C for several hours, a time scale at least two orders of magnitude greater than the time required for the dPS-NH2 chains to diffuse through the bulk PS layer. The topography of the interfacial region as copolymer formed was measured using atomic force microscopy (AFM). Roughening of the PS/PMMA interface was observed to varying degrees in all annealed samples. Furthermore, the extent of this roughening was found to depend on the PS matrix molecular weight. Reaction in the samples with a high molecular weight PS matrix resulted in a root mean square roughness approximately equal to the radius of gyration Rg of the copolymer. However, approximately twice as much roughening was observed in the low molecular weight PS matrix. This study reveals how the molecular weight of one of the phases can affect the rate of reaction at a polymer/polymer interface.

scholarly journals Common Origin of Filler Network Related Contributions to Reinforcement and Dissipation in Rubber Composites

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2534
Author(s):  
Sriharish Malebennur Nagaraja ◽  
Sven Henning ◽  
Sybill Ilisch ◽  
Mario Beiner
Keyword(s):  
Network Topology ◽  
Filler Content ◽  
Matrix Composition ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
Rubber Composites ◽  
Different Temperatures ◽  
Filler Network ◽  
General Perspective ◽  
Rubber Filler

A comparative study focusing on the visco–elastic properties of two series of carbon black filled composites with natural rubber (NR) and its blends with butadiene rubber (NR-BR) as matrices is reported. Strain sweeps at different temperatures are performed. Filler network-related contributions to reinforcement (ΔG′) are quantified by the classical Kraus equation while a modified Kraus equation is used to quantify different contributions to dissipation (ΔGD″, ΔGF″). Results indicate that the filler network is visco-elastic in nature and that it is causing a major part of the composite dissipation at small and intermediate strain amplitudes. The temperature dependence of filler network-related reinforcement and dissipation contributions is found to depend significantly on the rubber matrix composition. We propose that this is due to differences in the chemical composition of the glassy rubber bridges connecting filler particles since the filler network topology is seemingly not significantly influenced by the rubber matrix for a given filler content. The underlying physical picture explains effects in both dissipation and reinforcement. It predicts that these glassy rubber bridges will soften sequentially at temperatures much higher than the bulk Tg of the corresponding rubber. This is hypothetically due to rubber–filler interactions at interfaces resulting in an increased packing density in the glassy rubber related to the reduction of free volume. From a general perspective, this study provides deeper insights towards the molecular origin of reinforcement and dissipation in rubber composites.

Periodically poled KTA crystal investigated using coherent X-ray beams

2000 ◽  
Vol 33 (4) ◽  
pp. 1149-1153 ◽  
Author(s):  
P. Pernot-Rejmánková ◽  
P. A. Thomas ◽  
P. Cloetens ◽  
F. Lorut ◽  
J. Baruchel ◽  
...  
Keyword(s):  
Phase Difference ◽  
Domain Walls ◽  
Structural Information ◽  
Periodically Poled ◽  
Synchrotron Source ◽  
X Ray ◽  
Diffracted Waves ◽  
Coherent Beams ◽  
Diffraction Imaging ◽  
The Difference

The distribution of inverted ferroelectric domains on the surface and within the bulk of a periodically poled KTA (KTiOAsO4) single crystal has been observed using a simple X-ray diffraction imaging setup which takes advantage of the highly coherent beams available at a third-generation synchrotron source, such as the ESRF. This technique allows one to reveal the phase difference between the waves that are Bragg diffracted from adjacent domainsviafree-space propagation (Fresnel diffraction). The phase difference of the diffracted waves is mainly produced by the difference in phases of the structure factors involved, and contains precise structural information about the nature of the domain walls.

scholarly journals Fuzzy Knowledge Distance with Three-Layer Perspectives in Neighborhood System

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jie Yang ◽  
Tian Luo ◽  
Fan Zhao ◽  
Shuai Li ◽  
Wei Zhou
Keyword(s):  
Rough Sets ◽  
Structural Information ◽  
Boundary Region ◽  
Basic Element ◽  
Target Concept ◽  
Information Granule ◽  
Density Peaks ◽  
Neighborhood System ◽  
Neighborhood Rough Sets ◽  
The Difference

Information granule is the basic element in granular computing (GrC), and it can be obtained according to the granulation criterion. In neighborhood rough sets, current uncertainty measures focus on computing the knowledge granulation of single granular space and have two main limitations: (i) neglecting the structural information of boundary regions and (ii) the inability to reflect the difference between neighborhood granular spaces with the same uncertainty for approximating a target concept. Firstly, a fuzziness-based uncertainty measure for neighborhood rough sets is introduced to characterize the structural information of boundary regions. Moreover, from the perspective of distance, based on the idea of density peaks, we present a fuzzy-neighborhood-granule-distance- (FNGD-) based method to discover the relationship between granules in a granular space. Then, to characterize the difference between granular spaces for approximating a target concept, we present the fuzzy neighborhood granular space distance (FNGSD) and fuzzy neighborhood boundary region distance (FNBRD). FNGD, FNGSD, and FNBRD are hierarchically organized from fineness to coarseness according to the semantics of granularity, which provide three-layer perspectives in the neighborhood system.

The structure of hydrous flocs prepared by batch and continuous flow water treatment systems and obtained by optical, electron and atomic force microscopy

1997 ◽  
Vol 36 (4) ◽  
pp. 41-48 ◽  
Author(s):  
A. Cornelissen ◽  
M. G. Burnett ◽  
R. D. McCall ◽  
D. T. Goddard
Keyword(s):  
Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Continuous Flow ◽  
Structural Information ◽  
Preparation Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Optical Electron ◽  
Artefact Formation

This paper concerns the imaging of hydrous floc particles by Light Microscopy (LM), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM). The use of a microscope technique means that visual structural information is obtained, in contrast with other techniques measuring particle characteristics. It was found that when a preparation technique was used that involves cryogenic freezing of the sample, before observation in the SEM, larger (1-100 μm) floc particles could be imaged without the loss of structural information normally caused by drying the sample. Damage caused by drying was not apparent with the TEM technique used. It was shown that the various microscope techniques produced compatible results, together covering a wide size range (10 nm-5mm). This indicates that major artefact formation due to sample preparation is unlikely. It was furthermore shown that when a micro-scale continuous flow system was used the reproducibility of the floc structure observed increased.

FUNCTIONALIZATION OF EPDM RUBBER TOWARD BETTER SILICA DISPERSION AND REINFORCEMENT

2018 ◽  
Vol 92 (2) ◽  
pp. 219-236 ◽  
Author(s):  
Naresh D. Bansod ◽  
Bharat P. Kapgate ◽  
Pradip K. Maji ◽  
Anasuya Bandyopadhyay ◽  
Chayan Das
Keyword(s):  
Maleic Anhydride ◽  
Sol Gel ◽  
Silica Content ◽  
Rubber Matrix ◽  
Epdm Rubber ◽  
In Situ Silica ◽  
Grafted Epdm ◽  
Composite Properties ◽  
Rubber Filler

ABSTRACT Functionalization of non-polar ethylene propylene diene monomer (EPDM) rubber by melt grafting of maleic anhydride (MA) and in situ incorporation of sol–gel derived silica in the MA grafted EPDM has been done to prepare EPDM/silica composites to use dual benefits of both the approaches, which results in adequate rubber–filler compatibility, good filler dispersion, and enhanced composite properties. Controlled growth of silica up to 25 parts per hundred rubber (phr) is carried out with the solution sol–gel process using tetraethoxysilane (TEOS) as a silica precursor. Mechanical and dynamical properties of the composites are found to improve consistently as silica content increases. Furthermore, treatment of maleic anhydride grafted EPDM by γ-aminopropyltrimethoxysilane (γ-APS) results in remarkable improvement in composite properties even at the same silica content. This is attributed to the generation of uniformly dispersed spherically shaped nanosilica throughout the rubber matrix as observed in a transmission electron microscopic (TEM) study. This contributes to enhanced crosslinking density and improved rubber–filler interaction. In fact, the reinforcement effect brought by in situ silica relative to unmodified in situ silica/EPDM composites is found to be much higher than that reported in recent work on EPDM/in situ silica composites even with higher silica loading. The mechanical, rheological, and dynamic mechanical behaviors of all the composites are evaluated and compared in detail.

Growth of Double-Chained Cationic Surfactant Films on Mica

2006 ◽  
Vol 59 (6) ◽  
pp. 381 ◽  
Author(s):  
Annabelle Blom ◽  
Gregory G. Warr ◽  
Erica J. Wanless
Keyword(s):  
Atomic Force Microscopy ◽  
Alkyl Chain ◽  
Effect Of Temperature ◽  
Equilibration Time ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Difference ◽  
Chain Lengths ◽  
Gel Transition

The evolution of adsorbed dialkyl chained quaternary ammonium surfactant films with different alkyl chain lengths has been observed in situ using atomic force microscopy (AFM). Both di-C12DAB and di-C14DAB form a cohesive bilayer immediately, which is observed to strengthen with equilibration time. The slow equilibrium of di-C16DAB allows examination of the film at less than saturated coverage and reveals growth of the bilayer through the nucleation and coalescence of patches. The difference in height between higher and lower regions is insufficient for bilayer and monolayer regions and the postulated structure is that of regions of bilayer with different packing densities. The effect of temperature on film morphologies near the gel transition is also examined.

scholarly journals Comparison of Real Response and Theoretical Modeling of Pavement with Thick Asphalt Layers under Heavy Traffic Load

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Jingsong Shan ◽  
Hongmei Shao ◽  
Qiuzhong Li ◽  
Peili Sun
Keyword(s):  
Theoretical Model ◽  
Heavy Traffic ◽  
Field Tests ◽  
Fatigue Cracking ◽  
Field Measurements ◽  
Traffic Load ◽  
Theoretic Model ◽  
Static Modulus ◽  
Two Samples ◽  
The Difference

Two kinds of asphalt pavement with thick asphalt layers were used to construct two samples. In structure I, a semirigid base and graded crushed stone subbase were used. In structure II, a granular base and semirigid subbase layer were used. Responses of the two structures under traffic loads were measured using optical fiber sensors, and the differences between theoretical model results and field measurements were analyzed. Field measurements show that vertical compressive stress in structure I is larger than that in structure II. The maximum tensile strain of the asphalt layer is located at the bottom of the AC-25C layer in structure I and at the bottom of the AC-25F layer in structure II. The latter is significantly larger than the former, indicating the possibility of fatigue cracking induced by traffic load is higher in structure II. The measured tensile horizontal strain at the bottom of the semirigid layer is relatively low (<30εμ) in both structure I and structure II. In theoretical model, static modulus, dynamic modulus, and interface bonding ability are considered and theoretical responses are calculated. There are significant differences between the theoretical results and field test data. In the theoretic model, the material properties of layers and bonding status of adjacent layers all influence the results. In order to reduce the difference between the calculated and measured results, numerous material tests and field tests should be carried out.

scholarly journals On the feasibility of automated prediction of bug and non-bug issues

2020 ◽  
Vol 25 (6) ◽  
pp. 5333-5369 ◽  
Author(s):  
Steffen Herbold ◽  
Alexander Trautsch ◽  
Fabian Trautsch
Keyword(s):  
Development Process ◽  
State Of The Art ◽  
Structural Information ◽  
Past Research ◽  
Prediction Performance ◽  
Use Case ◽  
Bug Reports ◽  
Automated Prediction ◽  
The Difference ◽  
Null Pointer

Abstract Context Issue tracking systems are used to track and describe tasks in the development process, e.g., requested feature improvements or reported bugs. However, past research has shown that the reported issue types often do not match the description of the issue. Objective We want to understand the overall maturity of the state of the art of issue type prediction with the goal to predict if issues are bugs and evaluate if we can improve existing models by incorporating manually specified knowledge about issues. Method We train different models for the title and description of the issue to account for the difference in structure between these fields, e.g., the length. Moreover, we manually detect issues whose description contains a null pointer exception, as these are strong indicators that issues are bugs. Results Our approach performs best overall, but not significantly different from an approach from the literature based on the fastText classifier from Facebook AI Research. The small improvements in prediction performance are due to structural information about the issues we used. We found that using information about the content of issues in form of null pointer exceptions is not useful. We demonstrate the usefulness of issue type prediction through the example of labelling bugfixing commits. Conclusions Issue type prediction can be a useful tool if the use case allows either for a certain amount of missed bug reports or the prediction of too many issues as bug is acceptable.

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