玻璃纤维纸增强聚四氟乙烯基复合材料的制备

Preparation of glass fiber paper reinforced polytetrafluoroethylene-based composites

玻璃纤维增强聚四氟乙烯(PTFE)复合材料是应用于高频/高速电子领域的一类关键基础材料。针对玻璃纤维布浸渍路线制备的复合材料上胶量不高的问题,以无碱玻璃棉纤维、短切石英玻璃纤维作为原料,采用湿法成型技术通过改变玻璃棉的打浆度制备了一系列结构均一、孔隙率高的玻璃纤维纸,并通过进一步浸渍PTFE乳液,采用冷压烧结的方式制备了一系列具有高树脂含量的PTFE基复合材料。系统研究了纸张孔隙结构对上胶量的影响,同时对不同上胶量的PTFE基复合材料的性能进行了进一步探究。结果表明,通过降低玻璃棉的打浆度可以有效提高纸张的孔径、透气度、孔隙率从而获得更高的上胶量以制备出介电性能更加优异的介质基板材料。随玻璃棉打浆度由21°SR增加至46°SR,玻璃纤维纸的透气度由382mm/s降低至55mm/s,平均孔径由8.21µm降低至2.20µm。当所用玻璃棉打浆度为21°SR时,抄造的玻璃纤维纸孔隙率为89.7%,上胶量高达89.17%。此时PTFE基复合材料具有最优异的介电特性,相对介电常数为2.246,介电损耗为1.26‰。

Glass fiber reinforced polytetrafluoroethylene(PTFE)composites are key basic materials used in the field of high-frequency/high-speed electronics.Aiming at the problem that the amount of glue applied to composites prepared by the glass fiber cloth impregnation route is not high.A series of glass fiber paper with uniform structure and high porosity by changing the beating degree of glass wool were prepared using alkali-free glass wool fiber and quartz glass chopped fiber as raw materials,and through further impregnates PTFE emulsion,A series of PTFE-based composite dielectric materials with high resin content were prepared by cold pressing sintering.The effect of paper pore structure on the amount of glue applied was systematically studied,and the perfor‐mance of PTFE-based composites under different glue amounts was further explored.The results show that by reducing the beating degree of glass wool,the pore size,air permeability,and porosity of the paper can be effectively improve to obtain a higher glue amount to prepare dielectric substrate materials with better dielectric properties.As the beating degree of glass wool increases from 21°SR to 46°SR,the air permeability of glass fiber paper decreases from 382 mm/s to 55 mm/s,and the average pore size decreases from 8.21µm to 2.20µm.When the beating degree of the glass wool used is 21°SR,the porosity of the fabricated glass fiber paper is 89.7%,and the glue content can get as high as 89.17%.Meanwhile,the PTFE-based composite exhibites the best dielectric proper‐ties,with a relative dielectric constant of 2.246 and a loss tangent of 1.26‰.