A process for the preparation of a segmented thermoplastic elastomer, by conversion in a melt system of
a. one or more-OH and/or-COOH groups- containing bifunctional polyesters or polyester amides having a melting point not higher than 100°C and a molecular weight in the range of 500 to 5000, and,
b. one or more-OH and/or-COOH groups- containing bifunctional polyesters or polyester amides having a melting point not lower than 180°C and a molecular weight in the range of 500 to 5000 in the presence of such an amount of diisocyanate that the ratio between the number of -NCO groups and functional groups of both the low-melting and the high-melting compounds is at least 1,0 and at most 1,5, the transesterificafion catalyst present in one segment or in both being deactivated prior to the conversion process.
The polymers resulting from the process may be heated for several hours at a temperature of 240°C without losing their elastomeric properties.
一种制备分段热塑性弹性体的工艺,在熔融体系中通过以下物质的转化制备分段热塑性弹性体
a. 一种或多种含有 OH 和/或-COOH 基团的双官能团聚酯或聚酯酰胺,其熔点不高于 100°C,分子量在 500 至 5000 之间,以及
b. 含有一个或多个-OH 和/或-COOH 基团的双官能团聚酯或聚酯酰胺,其熔点不低于 180°C,分子量在 500 至 5000 之间,在有一定量的二
异氰酸酯存在的情况下,低熔点化合物和高熔点化合物的-NCO 基团和官能团的数量之比至少为 1.0,最多为 1.5,在转化过程之前,存在于一个部分或两个部分中的酯化泡沫催化剂已失活。
该工艺产生的聚合物可在 240°C 的温度下加热数小时而不会失去其弹性特性。