含磷木质素/聚磷酸铵硬质聚氨酯泡沫的制备及性能研究

在酸性条件下，先利用聚乙二醇、丙三醇对木质素进行液化反应制备得到液化产物，再通过苯膦酰二氯对液化产物进行改性制备出含磷木质素，并以含磷木质素为原料部分替代聚醚多元醇与多苯基甲烷多异氰酸酯反应，在添加等量的聚磷酸铵基础上，采用一次发泡法合成制备出含磷木质素/聚磷酸铵硬质聚氨酯泡沫。通过磷元素含量、红外光谱、扫描电镜、压缩性能、表观密度、极限氧指数、导热系数、烟密度总释放量等分析，系统评价了含磷木质素替代量对泡沫材料力学性能、热性能及防火性能的影响。结果表明：含磷木质素红外光谱在1350、1037、1200 cm⁻¹左右处出现了分别属于P=O伸缩振动峰、P—O—C（脂肪族）以及P—O—C（芳香族）的特征吸收峰，证明磷元素被成功引入至碱木质素结构；所制备的含磷木质素可以部分替代聚醚多元醇，与多苯基甲烷多异氰酸酯缩合反应生成聚氨酯泡沫；随着含磷木质素替代量逐渐从0%增加至34%，泡沫材料的颜色逐渐由白色转变为黄褐色，导热系数由0.073 W/(m·k)降低至0.055 W/(m·k)，绝热保温性能显著提高，压缩强度先增加后略有降低，吸水率先升高而后逐渐减小。

Preparation and Characterization of Phosphorus-containing Lignin/Ammonium Polyphosphate Rigid Polyurethane Foam

The lignin was liquefied using both polyethylene glycol and glycerol as the solvent under acidic conditions. Phospho-containing lignin(PL) was prepared by modifying the liquefied lignin with phenylphosphine dichloride. The rigid polyurethane foam of PL/ammonium polyphosphate(PLF) was synthesized using one-step foaming method by esterification reaction of polyether polyols with polyphenylmethane polyisocyanate on the basis of adding an equal amount of ammonium polyphosphate, in which part of polyether polyols was replaced with PL. The effect of PL content on the mechanical properties, thermal properties, and fire resistance of the foam materials were evaluated by comprehensive analysis, including phosphorus content, fourier transform infrared spectroscopy(FT−IR), scanning electron microscopy, compressive properties, apparent density, limiting oxygen index, thermal conductivity, and total smoke density release. The results indicated that the characteristic absorption peaks of FT−IR curve at 1350, 1037 cm−1, and 1200 cm−1 were corresponds to P=O stretching vibration peak, P—O—C(aliphatic) and P—O—C(aromatic), respectively, which confirmed the lignin was successfully grafted with phenylphosphine dichloride. The polyurethane foam gradually changed from white to yellowish brown, thermal conductivity decreased from 0.073 W/(m·k) to 0.055 W/(m·k), the performance of heat preservation improved significantly, and compressive strength and water absorption rate first increased and then decreased with the substitution of PL gradually increasing from 0% to 34%.