| 摘要 |
<p>A segmented thermoplastic copolyester elastomer containing recurring polymeric long chain ester units and short chain ester units. The long chain ester units are derived from dicarboxylic acids and poly(alkylene oxide) glycols. The segmented copolyester contains about 25-90 percent by weight of at least two short chain ester units, about 45-95 percent of the total of all short chain ester units have no side chain and have a melting point of at least 150.degree.C if in the form of a high molecular weight polymer derived only from short chain ester units. About 5 to 55 percent of the total of all short chain ester units have side chains said side chains having a length between 7 and 25 carbon atoms. Such segmented thermoplastic copolyester elastomers are suitable for certain specialty applications such as, for example, impact absorbers, coated fabrics, low pressure tubing and other uses where low hardness and modulus combined with high tear strength, high melting points, rapid crystallization rate, and good flexibility are needed.</p> |
