摘要
木质素是一种含有羟基的三维网状天然高分子,因其存在醇羟基和酚羟基,被广泛用于聚氨酯领域。采用木质素与聚醚二元醇,制备了木质素基聚氨酯密封胶。对合成的木质素基聚氨酯预聚体进行了FT-IR和TG分析,并探讨了木质素与聚醚二元醇的羟基比对预聚体性能的影响以及Ca CO3和潜固化剂对木质素基聚氨酯密封胶性能的影响。结果表明:木质素基聚氨酯密封胶预聚体中木质素与二元醇羟基物质的量比为2∶1时,拉伸强度可达2.38MPa、断裂伸长率为576%。聚氨酯密封胶中引入木质素使得聚氨酯密封胶在热分解初期热失重量较高,但后期热分解的剩余物保留率高。在木质素基聚氨酯密封胶加入不超过50%碳酸钙时,随着碳酸钙添加量的增加断裂伸长率降低,拉伸强度则随着碳酸钙添加量的增加而增加。噁唑烷类潜固化剂能够有效降低单组分湿固化聚氨酯密封胶在固化时胶层中的气泡。
Lignin is a kind of three-dimensional network natural polymer containing hydroxyl groups. Due to the presence of the alcoholic hy- droxyl group and phenolic hydroxyl group, the lignin is widely used in the field of polyurethane materials. The lignin-based polyurethane sealant is prepared with lignin and polyether glycols. The lignin-based polyurethane prepolymer is analyzed by FT-IR and TG, and the effect of hydroxyl molar ratio of lignin to polyether glycols on the properties of polyurethane prepolymer is studied, the effect of CaCO3 and latent curing agent on the perfor- mances of lignin based polyurethane sealant is also discussed. The results showed that when the hydroxyl molar ratio of lignin to polyether glycols is 2： 1, the tensile strength and the elongation at break of the sealant will be 2.38MPa and 576% respectively. The weight loss of the lignin based polyurethane sealant prepolymer is higher in the initial stage of thermal decomposition, hut the residue of polyurethane sealant prepolymer is higher than pure polyurethane prepolymer. When the calcium carbonate （less than 50%） is added into lignin-based polyurethane sealant, the elongation at break of the sealant is becoming lower with the increasing amount of calcium carbonate, and the tensile strength is improving. The oxazolidine latent curing agent can effectively reduce the bubbles in the one-component moisture curing sealant layer.
出处
《化学与粘合》
CAS
2015年第5期333-336,共4页
Chemistry and Adhesion
关键词
聚氨酯密封胶
木质素
预聚体
耐热性
Polyurethane sealant
lignin
prepolymer
thermostability
