A new method for the synthesis of high‐molar‐mass (MM), bio‐based polyols for elastic polyurethanes is developed. This process is based on the self‐condensation of low MM polyols (M_n ≈ 1000) and vacuum removal of the resulting glycerol. Self‐condensation products are hyperbranched estolide polyols with average MMs close to 3000 and hydroxyl numbers in the range of 40–95 mg KOH g⁻¹. Three polyols, one with primary and two with secondary hydroxyls and different functionalities, are studied. The transesterification proceeded much faster with primary hydroxyls, leading to high‐viscosity products. The effect of functionality and reactivity of starting polyols on properties is discussed.

中文翻译：

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生物基自浓缩多元醇

开发了一种合成弹性聚氨酯的高分子量（MM），生物基多元醇的新方法。这个过程是基于低MM多元醇的自缩合（M _Ñ ≈1000）并在真空除去生成的甘油。自缩合产物是高支链的estolide多元醇，平均MM接近3000，羟值在40–95 mg KOH g ^-1范围内。研究了三种多元醇，一种具有伯羟基，两种具有仲羟基和不同的官能度。与伯羟基的酯交换反应进行得更快，从而产生高粘度的产物。讨论了起始多元醇的官能度和反应性对性能的影响。