木质素低聚物衍生聚氨酯泡沫的制备及性能

Preparation and properties of polyurethane foam derived from lignin oligomer

针对木质素分子结构复杂、反应活性低、高值化利用不足等问题,从木质素高效可控降解、分子结构定向化学修饰以及复合功能化等方面出发,开展了木质素可控氢化降解以及基于木质素低聚物衍生聚氨酯泡沫(PUFs)材料的制备及性能调控研究。以Ni/ZrO_(2)/Hβ为催化剂,对木质素进行部分还原降解获得了高酚羟基含量的活性木质素低聚物,继而经氧丙基化改性,制备了高反应活性的木质素低聚物多元醇(LOP),通过^(31)P NMR和^(1)H NMR表征分析了木质素低聚物及LOP,探讨了木质素低聚物改性前后的结构变化。将LOP与大豆油多元醇复配构建了全生物基PUFs材料,考察了LOP的结构及用量等对PUFs材料的微观结构、形貌及其物理化学性能的作用与影响规律,探明了不同性能木质素低聚物衍生PUFs材料的制备工艺。研究结果表明,LOP的加入会导致PUFs材料的泡孔减小,闭孔率增加,进而有效改善PUFs力学性能和高温热稳定性,通过对LOP用量的调节,可实现不同强度PUFs的高效制备(压缩强度0.27~0.65 MPa)。

In view of the complex molecular structure,low reaction activity,and insufficient high-value utilization of lignin,this study started from problems of efficient and controllable degradation,molecular structure-oriented chemical modification,and composite functional modification of lignin,and carried out the research on controlled lignin hydrogenation degradation and the preparation and performance regulation of polyurethane foams(PUFs)derived from lignin oligomer.Reactive lignin oligomers with high phenol hydroxyl content were obtained by the controlled partial reduction degradation of lignin under the catalysis of Ni/ZrO_(2)/Hβ.High reactive lignin oligomer polyol(LOP)was obtained by oxopropyl modification of the obtained lignin oligomers.The structures of lignin oligomers and LOP were characterized by ^(31)P NMR and ^(1)H NMR.The structural changes of lignin oligomers before and after modification were explored.The full-biomass based PUFs were constructed by composite LOP with soybean oil polyol.The effects for the structure and dosage of LOP on the microstructure,morphology,and the physical and chemical properties of the obtained PUFs were investigated.The preparation processes of degraded lignin derived PUFs with different properties were explored.The results show that the addition of LOP leads to the decrease of their cell size and increase the closed cell ratio of the obtained PUFs,and thus effectively improves their mechanical properties and thermal stabilities.Adjusting the weight ratio of LOP,the PUFs with different strengths(compressive strength 0.27-0.65 MPa)can be prepared efficiently.