Effect of Interfacial Bonding on the Self-Adhesion of SBR and Neoprene

1984 ◽  
Vol 57 (1) ◽  
pp. 216-226 ◽  
Author(s):  
A. K. Bhowmick ◽  
A. N. Gent
Keyword(s):  
Adhesive Strength ◽  
Room Temperature ◽  
The Self ◽  
Structural Factors ◽  
Viscous Effects ◽  
Threshold Conditions ◽  
Different Types ◽  
Strain Induced Crystallization ◽  
Induced Crystallization ◽  
Strength Of Adhesion

Abstract When two elastomer layers are partially crosslinked in contact with each other, the strength of adhesion increases. This effect has now been studied for simple vulcanizates of SBR and for CR vulcanizates crosslinked with sulfur and/or oxide linkages. Under threshold conditions, e.g., at high temperatures and in the swollen state, when both viscous effects and strain-induced crystallization are virtually eliminated, the work of detachment is small and approximately proportional to the inferred degree of interlinking, rising from a few J/m2 when only Van der Waals' attractions are present, up to 40–70 J/m2 in the fully-interlinked state. No significant differences were observed between SBR and CR vulcanizates, or with different types of crosslinking of CR. The principal structural factors governing the adhesive strength under threshold conditions appear to be the number and length of the molecular strands comprising the network and crossing the interface. The threshold fracture energy is directly proportional to the density of such strands and is smaller for shorter strands, in accord with the theory of Lake and Thomas. Under normal conditions, e.g., at room temperature and in the unswollen state, CR vulcanizates were found to adhere much more strongly for a given degree of interlinking, presumably due to strain-induced crystallization. Indeed, some enhancement of strength persisted even at temperatures of 100–150°C, in the unswollen state.

scholarly journals Synthesis and Self-Assembly of Conjugated Block Copolymers

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 110
Author(s):  
Lin-Lin Xiao ◽  
Xu Zhou ◽  
Kan Yue ◽  
Zi-Hao Guo
Keyword(s):  
Thin Film ◽  
Block Copolymers ◽  
Conjugated Polymers ◽  
Self Assembly ◽  
The Self ◽  
Synthetic Methods ◽  
Future Research ◽  
Structural Factors ◽  
The Past ◽  
Different Types

In the past two decades, conjugated polymers (CPs) have drawn great attention due to their excellent conductivity and charge mobility, rendering them broad applications in organic electronics. Controlling over the morphologies and nanostructures of CPs is very important to improve the performance of CP-based devices, which is still a tremendously difficult task. Conjugated block copolymers (cBCPs), composed of different CP blocks or CP coupled with coiled polymeric blocks, not only maintain the advantages of high conductivity and mobility but also demonstrate features of morphological versatility and tunability. Due to the strong π–π interaction and crystallinity of the conjugated backbones, the self-assembly behaviors of cBCPs are very complicated and largely remain to be explored. In this tutorial review, we first summarize the general synthetic methods for different types of cBCPs. Then, recent studies on the self-assembly behaviors of cBCPs are discussed, with an emphasis on the structural factors that affect the morphologies of cBCPs both in bulk and thin film states. Finally, we briefly provide our outlook on the future research of the self-assembly of cBCPs.

A self-reinforcing and self-healing elastomer with high strength, unprecedented toughness and room-temperature reparability

2021 ◽  
Author(s):  
Yuhan Li ◽  
Wenjuan Li ◽  
Ailing Sun ◽  
Mengfan Jing ◽  
Xingjiang Liu ◽  
...  
Keyword(s):  
Room Temperature ◽  
High Strength ◽  
Self Healing ◽  
Polyurethane Elastomers ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

A mechano-responsive strategy, known as strain-induced crystallization, is proposed to tailor room-temperature self-healing, highly mechanically-strong and unprecedentedly tough polyurethane elastomers.

Temperature Dependence of the Self-Assembled Styrene Based Random Ionomers in Aqueous Solution

2003 ◽  
Vol 775 ◽  
Author(s):  
Sung-Hwa Oh ◽  
Ju-Myung Song ◽  
Joon-Seop Kim ◽  
Hyang-Rim Oh ◽  
Jeong-A Yu
Keyword(s):  
Partition Coefficients ◽  
Room Temperature ◽  
Aqueous Media ◽  
The Self ◽  
Spectroscopic Methods ◽  
Ion Content ◽  
Repeat Units ◽  
Notable Effect ◽  
Order Of Magnitude ◽  
Experimental Errors

AbstractSolution behaviors of poly(styrene-co-sodium methacrylate) were studied by fluorescence spectroscopic methods using pyrene as a probe. The mol% of methacrylate was in the range 3.6–9.4. Water and N,N-dimethylforamide(DMF) mixture was used as a solvent (DMF/water = 0.2 mol %). The critical micelle (or aggregation) concentrations of ionomers and the partition coefficients of pyrene were obtained the temperature range 10–80°C. At room temperature, the values of CMCs (or CACs) were in the range 4.7 ×10-6 5.3 ×10-6 g/mL and we could not find any notable effect of the content of ionic repeat units within the experimental errors. Unlike CMCs, as the ion content increased, partitioning of pyrene between the hydrophobic aggregates and an aqueous media decreased from 1.5 ×105 to 9.4 ×104. As the temperature increased from 10 to 80 °C, the values of CMCs increased less than one order of magnitude. While, the partition coefficients of pyrene decreased one order of magnitude and the effect of the ion content became negligible.

Simulating Self-Regeneration and Self-Replication Processes Using Movable Cellular Automata with a Mutual Equilibrium Neighborhood

2020 ◽  
Vol 29 (4) ◽  
pp. 741-757
Author(s):  
Kateryna Hazdiuk ◽  
◽  
Volodymyr Zhikharevich ◽  
Serhiy Ostapov ◽  
◽  
...  
Keyword(s):  
Cellular Automata ◽  
Cellular Automaton ◽  
Three Dimensional ◽  
Computer Models ◽  
The Self ◽  
Model Construction ◽  
Natural Phenomena ◽  
Different Types ◽  
Movable Cellular Automata ◽  
Self Replication

This paper deals with the issue of model construction of the self-regeneration and self-replication processes using movable cellular automata (MCAs). The rules of cellular automaton (CA) interactions are found according to the concept of equilibrium neighborhood. The method is implemented by establishing these rules between different types of cellular automata (CAs). Several models for two- and three-dimensional cases are described, which depict both stable and unstable structures. As a result, computer models imitating such natural phenomena as self-replication and self-regeneration are obtained and graphically presented.

Reconstructing the mechanical response of polybutadiene rubber based on micro-structural evolution in strain-temperature space: entropic elasticity and strain-induced crystallization as the bridges

Soft Matter ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 447-455 ◽  
Author(s):  
Pinzhang Chen ◽  
Yuanfei Lin ◽  
Jingyun Zhao ◽  
Lingpu Meng ◽  
Daoliang Wang ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Structural Evolution ◽  
Entropic Elasticity ◽  
Polybutadiene Rubber ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Micro-structural evolution of polybutadiene rubber in strain-temperature space, and the reconstruction of the macro-mechanical response.

Processing of Copper by Equal Channel Angular Pressing (ECAP) – Microstructure Investigations

2015 ◽  
Vol 641 ◽  
pp. 286-293
Author(s):  
Beata Leszczyńska-Madej ◽  
Maria W. Richert ◽  
Agnieszka Hotloś ◽  
Jacek Skiba
Keyword(s):  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Subgrain Size ◽  
Pure Copper ◽  
Shear Bands ◽  
Angular Pressing ◽  
Ecap Process ◽  
Transmission Electron ◽  
Different Types ◽  
Diffraction Patterns

The present study attempts to apply Equal-Channel Angular Pressing (ECAP) to 99.99% pure copper. ECAP process was realized at room temperature for 4, 8 and 16 passes through route BC using a die having angle of 90°. The microstructure of the samples was investigated by means both light and transmission electron microscopy. Additionally the microhardness was measured and statistical analysis of the grains and subgrains was performed. Based on Kikuchi diffraction patterns misorientation was determined. There were some different types of bands in the microstructure after deformation. The shear bands, bands and in the submicron range the microshear bands and microbands are a characteristic feature of the microstructure of copper. Also characteristic was increasing of the number of bands with increasing of deformation and mutually crossing of the bands. The intersection of a bands and microbands leads to the formation of new grains with the large misorientation angle. The measured grain/subgrain size show, that the grain size is maintained at a similar level after each stage of deformation and is equal to d = 0.25 – 0.32 μm.

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