Elastomer ((TOP))

Rubber-like solids with elastic properties are called elastomers. Polymer chains are held together in these materials by relatively weak intermolecular bonds, which permit the polymers to stretch in response to macroscopic stresses.

Elastomer

Elastomers are usually thermosets (requiring vulcanization) but may also be thermoplastic (see thermoplastic elastomer). The long polymer chains cross-link during curing (i.e. vulcanizing). The molecular structure of elastomers can be imagined as a 'spaghetti and meatball' structure, with the meatballs signifying cross-links. The elasticity is derived from the ability of the long chains to reconfigure themselves to distribute an applied stress. The covalent cross-linkages ensure that the elastomer will return to its original configuration when the stress is removed.

Specialty chemicals, also known as ready-to-use chemicals or formulated chemicals, are products where the focus is not on the composition but on their function and performance. According to SOCMA, a specialty chemical has only one or two core applications, while standard applications can have dozens of different uses. A typical example is a thermoplastic elastomer. TPEs can be grouped by market or by function. The portfolio of Kuraray includes a wide range of specialty chemicals. Some of them are complex. Our experts have in-depth knowledge and consult customers on technical questions regarding the application of our products.

From manufacturing to complete value-added assembly services, KEP is conveniently and proudly located in the American Heartland. Led by talented, dedicated people who put the customer first, KEP provides expertise for all of your elastomer and natural rubber tubing and dip-molded product needs.

Biodegradable polymers have significant potential in biotechnology and bioengineering. However, for some applications, they are limited by their inferior mechanical properties and unsatisfactory compatibility with cells and tissues. A strong, biodegradable, and biocompatible elastomer could be useful for fields such as tissue engineering, drug delivery, and in vivo sensing. We designed, synthesized, and characterized a tough biodegradable elastomer from biocompatible monomers. This elastomer forms a covalently crosslinked, three-dimensional network of random coils with hydroxyl groups attached to its backbone. Both crosslinking and the hydrogen-bonding interactions between the hydroxyl groups likely contribute to the unique properties of the elastomer. In vitro and in vivo studies show that the polymer has good biocompatibility. Polymer implants under animal skin are absorbed completely within 60 days with restoration of the implantation sites to their normal architecture.

If you need rubberized parts with aggressive chemical and temperature resistance, Xyfluor is made for you. This highly fluorinated elastomer easily handles amines, ketones, and hydrofluoric acid for static applications in temperatures ranging from -76F (-60C) to 450F (232C). Xyfluor is ideal for use in demanding high-volume applications such as mechanical seals and gaskets in a range of metering pumps, valves, and other high-performance equipment.

Xufluor is field-tested for performance and durability in extreme operating conditions. For examples of how this advanced elastomer can work for you, explore our Solutions for the Chemical Processing Industry.

Dielectric elastomers (DEs) can act as deformable capacitors that generate mechanical work in response to an electric field. DEs are often based on commercial acrylic and silicone elastomers. Acrylics require prestretching to achieve high actuation strains and lack processing flexibility. Silicones allow for processability and rapid response but produce much lower strains. In this work, a processable, high-performance dielectric elastomer (PHDE) with a bimodal network structure is synthesized, and its electromechanical properties are tailored by adjusting cross-linkers and hydrogen bonding within the elastomer network. The PHDE exhibits a maximum areal strain of 190% and maintains strains higher than 110% at 2 hertz without prestretching. A dry stacking process with high efficiency, scalability, and yield enables multilayer actuators that maintain the high actuation performance of single-layer films.

Extremely soft and highly compliant fluidic elastomer robots. (a) Ribbed planar manipulator.8(b) Cylindrical manipulator with gripper.11(c) Self-contained pneumatic fish.46(d) Spatial cylindrical manipulator.48(e) Self-contained hydraulic fish.9 Photo in panel (c) courtesy of Devon Jarvis for Popular Mechanics. Color images available online at www.liebertpub.com/soro

Soft robots exhibit continuum body motion, large-scale deformation, and relatively high compliance compared to traditional rigid-bodied robots.1 Such characteristics give this class of robots advantages like the ability to mitigate uncertainty with passive compliance,2 perform highly dexterous tasks,3 and exhibit resiliency.4 This work provides a recipe for designing and fabricating soft fluidic elastomer actuators and robotic systems.

Operative principle of producing material strain through fluidic power. (A) Fluid, shown in yellow, is entrapped in an elastomer channel. (B) When the fluid is pressurized, stress and therefore strain are generated in the material.

A conceptual representation of the ribbed segment morphology. The segment is composed of three layers produced from soft elastomer (a), embedded fluidic channels (b), inextensible, but flexible constraint (c), embedded fluid transmission lines (d), and ribbed structures (e). (A) The segment in an unactuated, or neutral state. (B) The segment in an actuated state where fluid within the agonist channel group is pressurized, producing bending about the inextensible axis. Color images available online at www.liebertpub.com/soro

Since this is a quasistatic process, fluid pressure and supply volume measurements can be used to determine the elastic potential fluid energy input into the actuation system. The actuation system consists of the elastomeric segment and the internal compressible transmission fluid. The elastic potential fluid energy serves as a comparative metric between the different actuator segment designs. The potential energy is calculated by

A ribbed manipulator, like that detailed in section 7.1, can be fabricated using lamination-based casting with heterogeneous embeddings. The specific approach for fabricating a six-segment manipulator is illustrated in Figure 11. Here, seven constraint supports (Fig. 11d) are 3D printed1 and placed into a constraint layer mold (Fig. 11f), which is also 3D printed. The constraint film (Fig. 11c) is cut from a thin acetal sheet8 using a laser2 and inserted through the aforementioned supports. Above and below the constraint film, eight pieces of silicone tubing (Fig. 11a) are threaded through the supports. Silicone rubber3 is then mixed and poured into the constraint layer mold, immersing tubing, film, and supports in a layer of elastomer to create the composite constraint layer (Fig. 11g). The uncured rubber inside the mold is then immediately degassed using a vacuum chamber.4 Once cured, small holes are created in the constraint layer to pierce the embedded tubing at specific locations, allowing each line to independently address a group of fluidic channels. Elastomer pieces containing channels (Fig. 11b) are casted and cured separately using a similar molding technique. Those cured elastomer pieces (Fig. 11b) are then carefully attached to both faces of the constraint layer using a thin layer of silicone rubber. Lastly, the printed feet (Fig. 11e) are attached to the constraint supports (Fig. 11d) to create an attachment point for ball transfers. These mechanisms help constrain the arm's motion to a plane.

We showed three fundamentally different fabrication processes and discussed their strengths and weaknesses when using them to build completely soft unit-modules that can be concatenated into multisegment manipulators or used for locomotion. The lamination and the lost-wax casting processes allow for the embedding of heterogeneous functional elements like constraint layers or tubes into a soft actuator. This facilitates the interfacing to pressure sources or other system components. The simplicity of the retractable pin fabrication method allows for rapid prototyping of simple fluidic elastomer actuators without the risk of failed lamination, and without the need for a wax core. The lost-wax casting allows for almost arbitrarily shaped pressurizable cavity structures, created as a monolithic body without weakening seams caused by a lamination technique.

Combining global reach with decades of experience in material innovation, we are experts in polyurethane and thermoplastic polyurethane (TPU) based elastomers and have in-depth knowledge of their application across a vast range of industries. We have an extensive portfolio of hot- and cold cast elastomers, hot casting machines and TPU elastomers and develop solutions to meet specific needs. We innovate to respond to key megatrends, such as automation, sustainability, energy conservation, comfort and health, safety and mobility. We build close partnerships with our customers and work across an international network of R&D and manufacturing locations to help solve complex challenges and deliver the highest levels of technical support and customer care.

All TPEs are composed of crystalline and amorphous domains, either as a blend or as a block co-polymer. the combination of crystalline and amorphous domains are what give TPEs their thermoplastic and elastomeric properties.

Elastomers are "elastic polymers," which is how they got their name. They are made of long, coiled polymer chains. These chains begin as monomers until they undergo polymerization, an artificial process that changes monomers into polymers, which stretch when pulled and return to their arrangement when released, producing their elastic properties. Since rubber also has elastic properties, "elastomer" and "rubber" have become interchangeable, though they don't necessarily always refer to the same material. 041b061a72