溶剂法木质素的多元醇改性与聚氨酯硬质泡沫制备

Chemical Modification of Organosolv Lignin into Polyol and Preparation of Polyurethane Rigid Foam

关键词:  溶剂法木质素  聚氨酯泡沫  多元醇  压缩强度

Key Words:organosolv lignin  polyurethane foam  polyols  compressive strength

摘要:本研究开展了溶剂法木质素的化学改性和木质素基多元醇的合成，以及聚氨酯硬质泡沫的制备，对溶剂法木质素进行结构表征，对改性合成的木质素基多元醇进行黏度、酸值、羟值检测，对制备的含木质素的聚氨酯硬质泡沫进行导热系数、压缩强度、表观密度的检测。结果表明，木质素基多元醇的羟值为920 mg KOH/g、酸值为4.76 mg KOH/g。木质素基多元醇的黏度随温度升高而降低，25 ℃时黏度为15 832 mPa·s，80 ℃时黏度降低至3 057 mPa·s。异氰酸酯、发泡剂、表面活性剂用量均会对聚氨酯硬质泡沫的压缩强度产生影响，在最优配比下，制备的木质素基聚氨酯泡沫的压缩强度为370 kPa、密度为77 kg/m³、导热系数为0.037 1 W/(m·K)。通过调整酸值和催化剂用量，发泡时间可从320 s缩短至35 s。

Abstract:In this study， chemical modification of organosolv lignin was carried out to synthesize lignin-based polyols and then prepared polyurethane foam. The structure of organosolv lignin was characterized. The prepared lignin-based polyols were tested for viscosity， acid value， hydroxyl value. The thermal conductivity， compressive strength， and apparent density of the synthesized bio-based foam were tested. The results showed that the hydroxyl value of lignin-based polyol was 920 mg KOH/g， and acid value was 4.76 mg KOH/g. Viscosity of lignin polyols decreased with temperature. Viscosity reduced from 15 832 mPa·s at 25 ℃ to 3 057 mPa·s at 80 ℃. The amount of isocyanate， foaming agent， and surfactant all affected compressive strength of polyurethane foam. Finally， the lignin-based polyurethane foam showed compressive strength of 370 kPa， density of 77 kg/m³， and thermal conductivity of 0.037 1 W/(m·K) under the optimal ratio. The foaming time was shortened from 320 s to 35 s by adjusting the acid value or catalyst dosage.