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Elastomeric Material (elastomeric + material)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Microfluidic Endoskeletons: Materials of Controlled Shape and Stiffness with Photocurable Microfluidic Endoskeleton (Adv. Mater.

ADVANCED MATERIALS, Issue 27 2009
27/2009)
Photocurable microfluidic channel networks in thin layers of polydimethylsiloxane can act as on-demand endoskeletons to lock-in specific shapes, report Orlin Velev and co-workers on p. 2803. The light-induced solidification of photopolymer inside the microchannel networks leads to drastic increases in the elastic and bending moduli of the elastomeric material. The fabrication process is simple and scalable, and could make use of other shape-memory materials, creating the potential to fabricate custom shapes (e.g., containers, protective exoskeletons, or supports) using simple heat, light, or magnetic/electric field triggers. [source]

Materials of Controlled Shape and Stiffness with Photocurable Microfluidic Endoskeleton

ADVANCED MATERIALS, Issue 27 2009
Suk Tai Chang
Photocurable microfluidic channel networks in thin layers of polydimethylsiloxane can act as on-demand endoskeletons to lock-in specific shapes. The light-induced solidification of photopolymer inside the microchannel networks leads to drastic increases in the elastic and bending moduli of the elastomeric material. [source]

Synthesis and Characterization of Ethylene/Propylene Copolymers in the Whole Composition Range

MACROMOLECULAR SYMPOSIA, Issue 1 2007
Ma. Joaquina Caballero
Abstract Summary: The incorporation of comonomer molecules in the backbone of a homopolymer can influence the final properties of the material, decreasing its crystallinity and the melting and glass transition temperatures, and increasing its impact resistance and transparency. In the present work, ten ethylene/propylene copolymers have been synthesized using a supported metallocene catalytic system covering the whole composition range. Any desired composition was obtained by controlling the feed composition during the reaction. These synthesized copolymers have been characterized by different techniques in order to study the effect of the comonomer incorporation onto their final properties. When the comonomer content is low, the behaviour of the copolymer is similar to that of the corresponding homopolymer. Nevertheless, if the comonomer content increases, the copolymer becomes more amorphous (low crystallization temperature and soft XRD signals) and easily deformable, reaching a behaviour close to that corresponding to an elastomeric material. In order to corroborate these results the samples have been characterized by TREF and GPC-MALS. TREF analysis showed that copolymers containing less than 10% and more than 80% of ethylene are semicrystalline, with elution temperatures typical of this kind of polymers. Molecular weights are higher for homopolymers and they decrease as the comonomer concentration increases, whereas the polydispersity index keeps almost constant at the expected value for this kind of samples. [source]

Elastomer biaxial characterization using bubble inflation technique.

POLYMER ENGINEERING & SCIENCE, Issue 3 2001
II: Numerical investigation of some constitutive models
An elastomeric material was investigated with a bubble inflation rheometer, and its mechanical behavior was modeled as a rubbeer-like solid. Classical strain energy functions were considered and the hyper-elastic were calculated by a direct identification procedure from simple uniaxial and equibiaxial extension test data, and the reults are compared against those obtained by an inverse method from matching the meaured response to a finite element to a finite element analysis solution, which dependent on the unknown material parameters. The optimised employed the Levenberg-Marquardt algorithm and Abaqus software to compute the cost function and its gradients. The constants so obtained were further used in finite element analysis, and the numerical results were compared with experiments. This study showed that the inverse method, used to estimate the material parameters, is a good alternative to the direct identification, especially since the latter often requires homogeneous strain state, which is very difficult to obtain. [source]

Polyamide 66 binary and ternary nanocomposites: Mechanical and morphological properties

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2010
Miray Mert
Abstract Polyamide 66 (PA 66)/impact modifier blends and polyamide/organoclay binary and PA 66/organoclay/impact modifier ternary nanocomposites were prepared by the melt-compounding method, and the effects of the mixing sequences on the morphology and mechanical and flow properties were investigated. Lotader AX8840 and Lotader AX8900 were used as impact modifiers. The concentrations of the impact modifiers and the organoclay (Cloisite 25A) were maintained at 2 and 5 wt %, respectively. Both the binary and ternary nanocomposites displayed high tensile strength and Young's modulus values compared to the PA 66/impact modifier blends. Decreases occurred in the strength and stiffness of the binary nanocomposites upon incorporation of the elastomeric materials into the polymeric matrix. In general, the mixing sequence in which all three ingredients were added simultaneously and extruded twice (the All-S mixing sequence) exhibited the most enhanced mechanical properties in comparison with the mixing sequences in which two of the components were extruded in the first extrusion step and the third ingredient was added in the second extrusion step. The mechanical test results were in accordance with the organoclay dispersion. The impact strength was highly affected by the elastomeric domain sizes, interdomain distances, interfacial interactions, and organoclay delamination. The smallest elastomeric domain size was obtained for the All-S mixing sequence, whereas the elastomeric domain sizes of the other mixing sequences were quite close to each other. Drastic variations were not observed between the melt viscosities of the ternary nanocomposites prepared with different mixing sequences. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]