基于酰基氨基脲和脲键协同作用的自愈合聚脲材料的制备及性能

Preparation and properties of a self-healing polyurea material based on the synergistic effect of acylsemicarbazide and urea bond

[目的]制备具有优异力学性能和室温自愈合能力的材料具有极大的挑战性。[方法]以间苯二甲酰肼(IPDH)和硫脲为扩链剂,通过在聚合物硬段中引入酰基氨基脲和脲键基团来制备室温自愈合聚脲材料,分析了不同氢键密度下聚合物的化学结构、热学性能、力学性能和自愈合性能。[结果]以IPDH与硫脲的物质的量比3∶2所制备的材料显示了较好的综合力学性能:拉伸强度19.33 MPa,断裂伸长率929.6%,韧性52.69 MJ/m^(3)。聚合物中存在的多种氢键作用赋予了材料优异的自愈合能力。断裂试样经25℃修补5 h后断裂面基本消失,36 h后拉伸强度和断裂伸长率均恢复了至少80%。[结论]该材料可以在温和的条件下愈合,在智能保护材料方面有潜在的应用前景。

[Introduction]The preparation of materials possessing exceptional mechanical strength and self-healing ability at ambient temperature presents a formidable challenge.[Method]By incorporating acylsemicarbazide and urea bond groups into the hard segment of the polymer,a self-healing polyurea material was synthesized at room temperature using isophenylhydrazine(IPDH)and thiourea as chain extenders.The effect of hydrogen bond density on the chemical structure,thermal properties,mechanical properties,and self-healing performance of the polyurea material was studied.[Result]The polymer synthesized at a IPDH-to-thiourea molar ratio of 3:2 had good comprehensive mechanical properties:tensile strength 19.33 MPa,elongation at break 929.6%,and toughness 52.69 MJ/m^(3).The presence of diverse hydrogen bonds within the polymer confers exceptional self-healing ability upon the material.The fracture surface was nearly imperceptible after 5 hours of repair at ambient temperature,and the recovery rates of tensile strength and elongation at break exceeded 80%after 36 hours.[Conclusion]The material exhibits the ability to undergo self-healing under mild conditions,thereby demonstrating promising prospects for application in intelligent protective materials.