New TPU has 'elastic memory.' (thermoplastic polyurethane)A novel "shape-memory" thermoplastic resin Noun 1. thermoplastic resin - a material that softens when heated and hardens again when cooled thermoplastic plastic - generic name for certain synthetic or semisynthetic materials that can be molded or extruded into objects or films or filaments or used technology developed by Mitsubishi Heavy Industries Ltd., Tokyo, is in the test marketing stages in the U.S. Mitsubishi's Shape Memory Polymer has several commercial medical industrial and consumer applications in Japan. Two unidentified U.S. firms are seeking FDA FDA abbr. Food and Drug Administration FDA, n.pr See Food and Drug Administration. FDA, n.pr the abbreviation for the Food and Drug Administration. approval for extruded prototypes in medical applications. The resin is available in sample quantities from Memory Technologies Inc., Brookfield, Conn. Mitsubishi describes its Shape Memory Polymer as a thermoplastic A polymer material that turns to liquid when heated and becomes solid when cooled. There are more than 40 types of thermoplastics, including acrylic, polypropylene, polycarbonate and polyethylene. polyurethane with "elastic memory." When a molded or extruded part is heated above the resin's glass-transition temperature ([T.sub.g]) but below its melt temperature, it changes from a rigid, glassy state to a rubbery state at which it is highly flexible and pliant, allowing it to be deformed to a new shape that can be "frozen" in by cooling below the Tg. If the deformed part is subsequently heated above the [T.sub.g], the resin will "remember" its original molded shape and spontaneously return to that shape. The resin's shape-memory properties can be tailored for various applications by formulating the polymer for a specific Tg (to within 1[degrees] F) over a wide [T.sub.]g range (-30 F to +158 F). The polymer is available as an ether- or ester-based polyurethane in pellet form that can be injection molded or extruded similar to traditional TPUs. The material has a sample-quantity price of about $30 lb. There are currently four grades in each of three series, which fall into four [T.sub.g] ranges (77F, 86F, 95F, 113F, and 131 F). Besides pellet form, the, material also is available as a solution, foam, or two-component liquid resin system. As a representative example, Shape Memory Polymer MM-5500 (55 C or 131 F [T.sub.g]) has Shore D hardness range between 74 and 32, elongation at yield of over 400%, specific gravity specific gravity, ratio of the weight of a given volume of a substance to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the two substances. of 1.18 and tensile strength tensile strength Ratio of the maximum load a material can support without fracture when being stretched to the original area of a cross section of the material. When stresses less than the tensile strength are removed, a material completely or partially returns to its of 3959 psi. As for processing recommendations, the company says the resin pellets must be dried to 0.03% moisture (4 hr at 176 F), and processors should guard against the resin's tendency to reabsorb reabsorb to absorb again; to undergo or to subject to reabsorption; to resorb. moisture quickly from ambient air. The material has a melt-viscosity curve similar to standard TPU TPU - Text Processing Utility , PP or ABS, but is more thermal-dependent than those polymers. Mitsubishi offers a full processing guide for the material. (CIRCLE 1) 
Good Afternoon,<br><br>I´m master student of Uminho University, in Potugal. I have visited your website, because I´m researching about Shape Memory Polymers, precisely looking for SMP yarns, to use in textile research. Do you have some contact of SMP Yarn manufacturer or supplier?<br><br>With the best regards, <br><br>Tatiana Laschuk<br>Master Researcher Student<br>Uminho University<br><br><br> |
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