石墨烯纳米片/密胺复合泡沫性能增强机制研究

Performance Enhancement Mechanism of Graphene Nanosheets/Melamine Composite Foam

目的探究三聚氰胺与甲醛原料比例、发泡剂正戊烷含量、乳化剂OP-10含量和固化剂甲酸含量对密胺泡沫发泡过程的影响及作用机理,并制备石墨烯纳米片/密胺复合泡沫材料,改善密胺泡沫力学性能,提高密胺泡沫材料热稳定性以及阻燃性。方法通过调整原料比例、改变不同助剂的掺量探究发泡工艺对泡沫结构的影响,并研究石墨烯纳米片对复合泡沫性能的增强机制。对样品进行力学性能测试,并通过扫描电子显微镜和热重分析仪对泡沫微观结构和热力学性能进行分析。结果当三聚氰胺与甲醛物质的量之比为1︰3~1︰4时,预聚体交联度高,结构完整;当正戊烷质量分数为33%时,能够为预聚体提供足够的成核点;当甲酸质量分数为8%时,固化速度适宜;当OP-10质量分数为4%~6%时,有效降低了界面张力。添加石墨烯纳米片使复合泡沫最高压缩强度达到23.86 kPa,最高残碳率上升为8.24%,热导率仅上升0.006 W/(m·K),保持了良好的保温隔热性能。结论甲醛与三聚氰胺的物质的量之比会影响预聚体交联程度;正戊烷因其低沸点而促进了泡沫成核;甲酸通过为基体提供更多的交联点加速了固化速度;OP-10在发泡过程中通过调整与发泡剂的相容性以及作为表面活性剂发挥了作用。石墨烯纳米片的添加提高了复合泡沫的力学性能,在保持低密度和低热导率的同时进一步增强了其热稳定性及其阻燃能力。

The work aims to explore the effect and mechanism of melamine formaldehyde raw material ratio,foaming agent n-pentane,emulsifier OP-10 and curing agent formic acid on the foaming process of melamine foam,and prepare graphene nanoflakes/melamine composite foam materials,improve the mechanical properties of melamine foam,and improve the thermal stability and flame retardancy of melamine foam materials.The effect of foaming process on the structure of foam was explored by adjusting the proportion of raw materials and the amount of different additives,and the mechanism of graphene nanoflakes on the performance enhancement of composite foam was studied.The mechanical properties of the samples were tested by compression test,and the microstructure and thermal stability of foam were analyzed by scanning electron microscope and thermogravimetric analyzer.When the ratio of melamine to formaldehyde solution is 1∶3-1∶4,the crosslinking degree of the prepolymer was high and the structure was complete;The addition of 33 wt%n-pentane could provide sufficient nucleation points for the prepolymer;When the addition content of formic acid was 8 wt%,the curing rate was appropriate;The addition of OP-10 with a content of 4%-6%effectively reduced the interfacial tension.The addition of graphene nanoflakes made the maximum compressive strength of the composite foam reached 23.86 kPa,the maximum carbon residue rate rose to 8.24%,and the thermal conductivity rose only 0.006 W/(m·K),maintaining good thermal insulation performance.The ratio of formaldehyde solution to melamine affects the degree of crosslinking of prepolymers;N-pentane promotes foam nucleation because of its low boiling point;Formic acid accelerates the curing rate by providing more crosslinking points for the matrix;OP-10 works as a surfactant during the foaming process by adjusting its compatibility with foaming agents.The addition of graphene nanosheets improves the mechanical properties of composite foam,and further enhances its thermal stability and flame retardancy while maintaining low density and low thermal conductivity.