Mechanical Properties of Polymer Gels with Bimodal Distribution in Strand Length

2013 ◽  
Vol 46 (17) ◽  
pp. 7027-7033 ◽  
Author(s):  
Shinji Kondo ◽  
Hayato Sakurai ◽  
Ung-il Chung ◽  
Takamasa Sakai
Keyword(s):  
Mechanical Properties ◽  
Polymer Gels ◽  
Bimodal Distribution ◽  
Strand Length

scholarly journals Mechanical properties of polymer gels with bimodal distribution in strand length

2014 ◽  
Vol 1622 ◽  
pp. 31-36
Author(s):  
Shinji Kondo ◽  
Ung-il Chung ◽  
Takamasa Sakai
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Polymer Gels ◽  
Bimodal Distribution ◽  
Heterogeneous Distribution ◽  
Molecular Weights ◽  
Ultimate Deformation ◽  
Cross Links ◽  
Deformation Ratio ◽  
Strand Length

ABSTRACTThe understanding of the physical properties of hydrogels has been controversial because hydrogels inherently have a substantial amount of heterogeneities in their structures. In this study, we focused on one of the simplest heterogeneities, heterogeneous distribution of strand length, and investigated its influence on physical properties. We prepared Tetra-PEG gels with bimodal distribution in strand length (Tetra-PEG bimodal gels) by combining Tetra-PEG prepolymers with different molecular weights and measured the physical properties including elastic modulus and ultimate deformation ratio. The physical properties of Tetra-PEG bimodal gels were well described by the models for conventional Tetra-PEG gels with the average polymerization degrees between cross-links. We conclude that the mechanical properties of hydrogels that have heterogeneous distribution in strand length can be predicted from those of hydrogels with the average strand length in the range tested in this study.

scholarly journals Relationships between Mechanical Properties of Polymer Gels and Polymer Volume Fractions at Preparation and at Interested State

2014 ◽  
Vol 42 (2) ◽  
pp. 97-102 ◽  
Author(s):  
Takuya Katashima ◽  
Manami Kurakazu ◽  
Yuki Akagi ◽  
Ung-il Chung ◽  
Takamasa Sakai
Keyword(s):  
Mechanical Properties ◽  
Polymer Gels ◽  
Volume Fractions ◽  
Polymer Volume

The Constitutive Response of Active Polymer Gels

1999 ◽  
Vol 600 ◽  
Author(s):  
S. P. Marra ◽  
K. T. Ramesh ◽  
A. S. Douglas
Keyword(s):  
Mechanical Properties ◽  
Acrylic Acid ◽  
Vinyl Alcohol ◽  
Polymer Gels ◽  
Mechanical Deformation ◽  
Poly Vinyl Alcohol ◽  
Artificial Muscles ◽  
Ionic Polymer ◽  
Constitutive Response ◽  
Ph Level

AbstractActive polymer gels can achieve large, reversible deformations in response to environmental stimuli, such as the application of an electric field or a change in pH level. Consequently, great interest exists in using these gels as actuators and artificial muscles. The goal of this work is to characterize the mechanical properties of ionic polymer gels and to describe how these properties evolve as the gel actuates. Experimental results of uniaxial tests on poly(vinyl alcohol)-poly(acrylic acid) gels are presented for both acidic and basic environments. These materials are shown to be to be slightly viscoelastic and compressible and capable of large recoverable deformations. The gels also exhibit similar stress in response to mechanical deformation in both the acid and the base.

Effects of Particle Size and Size Distribution on the Mechanical Properties of EPDM/Silica Vulcanizates

2008 ◽  
Vol 47-50 ◽  
pp. 113-116 ◽  
Author(s):  
M.N. Ichazo ◽  
C. Albano ◽  
M. Hernández ◽  
J. González ◽  
A. Carta
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Size Distribution ◽  
Surface Area ◽  
Bimodal Distribution ◽  
Epdm Rubber ◽  
Surface Areas ◽  
Precipitated Silica ◽  
Internal Mixer ◽  
Tear Properties

In this work we present the influence of different particle size (surface areas: 120,150, 200 and 250 m2/g) and size distribution of precipitated silica on the mechanical properties of Ethylene- Propylene-Diene (EPDM) rubber. The vulcanization system employed was efficient. Compounds were prepared using a Banbury internal mixer. Tensile and tear properties of vulcanized blends were determined according to ASTM D412 and ASTM D624 procedures, respectively. Results show an increasing tendency on tensile properties when particle size decreases, due to the better dispersion of the filler and to a greater interaction with the rubber. Increases of up to 500% on tensile strength and 400% on tear strength were observed. However, there was an incoherent behavior for the silica with surface area of 200 m2/g (Si-200), so size distribution of the aggregates was experimentally determined by a microphotography study. Secondary aggregates size distribution was very different for each type of silica. Aggregates for Si-200 presented a bimodal distribution where the greater frequencies correspond to aggregates with surface area higher than the corresponding values for the Si-120. This fact could explain why the mechanical properties of the EPDM filled with Si-200 are not in between the values of the compounds filled with Si-150 and Si-250.

scholarly journals Swelling and Mechanical Properties of Polymer Gels.

Kobunshi ◽  
1994 ◽  
Vol 43 (8) ◽  
pp. 554-557
Author(s):  
Toshikazu Takigawa ◽  
Toshiro Masuda
Keyword(s):  
Mechanical Properties ◽  
Polymer Gels

scholarly journals Generation of increased mechanical properties of Cantor high­entropy alloy

2021 ◽  
Vol 64 (8) ◽  
pp. 599-605
Author(s):  
V. E. Gromov ◽  
Yu. A. Rubannikova ◽  
S. V. Konovalov ◽  
K. A. Osintsev ◽  
S. V. Vorob’ev
Keyword(s):  
Mechanical Properties ◽  
Cast Alloy ◽  
Bimodal Distribution ◽  
Additive Technology ◽  
Plastic Properties ◽  
Torsional Strain ◽  
Dislocation Glide ◽  
Electron Beam Processing ◽  
Strength And Plasticity ◽  
High Level

The article considers a brief review of the last years of Russian and foreign research on the possibilities of improving mechanical properties of the Cantor quinary high­entropy alloy (HEA) with different phase composition in wide temperature range. The alloy, one of the frst created equimolar HEAs with FCC structure, needs mechanical properties improvement in accordance with possible felds of application in spite of its high impact toughness and increased creep resistance. It has been noted that bimodal distribution of the grains by sizes under severe plastic torsional strain at high pressure of 7.8 GPa of cast alloy and subsequent short­time annealing at 873 and 973 K can change strength and plastic properties. Nanodimensional scale of the grains surrounded by amorphous envelope has been obtained for HEA produced by the method of magnetron sputtering and subsequent annealing at 573 K. In such a two­phase alloy nanohardness amounted to 9.44 GPa and elasticity modulus – to 183 GPa. Using plasticity effect induced by phase transformation in (CrMnFeCoNi)50Fe50 alloy obtained by the method of laser additive technology the ultimate strength of 415 – 470 MPa has been reached at high level of plasticity up to 77 %. It has been ensured by FCC → BCC diffusionless transformation. It is shown that difference in mechanisms of plastic strain of cast alloy at 77 K and 293 K (dislocation glide and twinning) determines a combination of increased “strength­plasticity” properties. Samples for generation of twins prestrained at 77 K exhibit increased strength and plasticity under subsequent loading at 293 K in comparison with the unstrained ones. For HEA obtained by laser additive technology this way of increasing properties is also true. The way of improving mechanical properties at the expense of electron beam processing is noted. The attention is paid to the necessity of taking into account the role of entropy, crystal lattice distortions, short­range order, weak diffusion and “cocktail” effect in the analysis of mechanical properties.

Elastomers and Rubberlike Elasticity

2015 ◽  
Author(s):  
James E. Mark ◽  
Burak Erman
Keyword(s):  
Mechanical Properties ◽  
Liquid Crystalline ◽  
Random Network ◽  
Polymer Gels ◽  
Solvent Exchange ◽  
Specific Chemical ◽  
Functional Monomers ◽  
Elastomeric Materials ◽  
Deformed State ◽  
High Deformability

This article focuses on the rubberlike elasticity of elastomers, with particular emphasis on rubberlike materials that exhibit high deformability and recoverability. It begins with a discussion of the variety of practical ways to form and characterize a rubber-elastic network, including random chemical crosslinking, highly specific chemical end-linking, polymerizations with multi-functional monomers, physical aggregation, and crosslinking in solution and in the deformed state. It then considers the effects of network structure on elastomeric properties, along with the results of elasticity experiments regarding the mechanical properties of elastomeric materials. It also examines the evolution of theories of rubber elasticity describes the specific properties of swollen polymer gels where the possibility of solvent exchange leads to some dramatic transformations in the system. Finally, it evaluates new emerging classes of rubber-elastic materials, such as liquid crystalline elastomers, where the internal microstructure added to the random network leads to some unique mechanical properties.

Bimodal Distribution of Microstructure and Mechanical Properties of Plasma Sprayed Nanostructured Al2O3-13wt% TiOB2 Coatings

2011 ◽  
Vol 26 (9) ◽  
pp. 1003-1008 ◽  
Author(s):  
Xue-Cheng LU ◽  
Dian-Ran YAN ◽  
Yong YANG ◽  
Ji-Ning HE ◽  
Jian-Xin ZHANG ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bimodal Distribution ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sprayed

Silica Nano-particle Filled Poly(ethylene-ran-hexene)/xylene Gels

2000 ◽  
Vol 661 ◽  
Author(s):  
Howard Wang ◽  
Charles C. Han
Keyword(s):  
Mechanical Properties ◽  
Small Angle ◽  
Structure Factor ◽  
Small Angle Neutron Scattering ◽  
Particle Interaction ◽  
Polymer Gels ◽  
Nano Particle ◽  
Rheological Measurements ◽  
Silica Filler ◽  
Poly Ethylene

The effect of silica nano-particle filler on poly(ethylene-co-hexene)/xylene gels has been investigated using mainly small angle neutron scattering and rheological measurements. Both non-filled and filled polymer gels show same characteristics in the structure factor and mechanical properties during melting and gelation. These observations suggest that particle interaction is screened by the absorbed polymers and the effect of the silica filler is mainly softening the gelation transition by introducing defects to the crosslinking microcrystals.

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