摘要 |
<p>Copolyester-diol polycarbonates fluid at room temperature, having a number average molecular weight comprised within the range of from 1,500 to 6,000 with a glass transition temperature (Tg) lower than -45 DEG C, useful in the sector of polyurethanes and in the sector of sealants, are obtained by means of a reaction of transesterification by starting from: (a) and organic carbonate, (b) an aliphatic diol, (c) an oligopolyester-diol. This latter is the product of reaction of an aliphatic bicarboxy acid with a mixture of two or more diols, comprising neopentyl glycol.</p> |