Ye Xinming, Jing Xinyi, Liu Yunlan, Han Zhiqing, Yang Fan, Qiao Liang, Ren Jie, Meng Linggong, Li Zhimao, Wang Wensheng, Li Jie, Li Yingchun
School of Materials Science and Engineering, North University of China, No. 3 Xueyuan Road, Taiyuan 030051, Shanxi, P. R. China.
North University of China, No. 3 Xueyuan Road, Taiyuan 030051, Shanxi, P. R. China.
ACS Appl Mater Interfaces. 2024 Sep 18;16(37):49763-49777. doi: 10.1021/acsami.4c09639. Epub 2024 Sep 6.
For industrial practical applications, it is difficult to simultaneously endow epoxy resin (EP) composites with superior flame retardancy, smoke suppression, toughness, and low-dielectric constants. Herein, unique polyhedral oligomeric silsesquioxane/polyoxometalate (POM(Mo)-POSS(ibu-Li)) nanosheets were synthesized via a simple one-pot method using laboratory-made lithium-containing hepta-isobutyl-POSS (ibu-Li-POSS) and the low-cost industrial chromogenic agent HPMoO as raw materials. The incorporation of 2 wt % POM(Mo)-POSS(ibu-Li) nanoflakes into EP significantly enhanced the compatibility between nanoadditives and the EP matrix. Compared with EP, the flexural and impact strengths increased by 36.2 and 78.2%, respectively. Therefore, POM(Mo)-POSS(ibu-Li) has significant advantages in enhancing the toughness of EP compared with existing flame retardants. The dielectric constant and loss were apparently reduced to meet the increasing requirements of EP-type electronic packaging materials and components. Notably, the synthesized POM(Mo)-POSS(ibu-Li) contained various flame-retardant and smoke-suppression elements such as P, Mo, and Si. The ultralow loading (2 wt %) of POM(Mo)-POSS(ibu-Li) significantly reduced the peak heat release rate, peak of smoke production rate, and CO production rate by 43.9, 40.6, and 65.8%, respectively. Meanwhile, the value of LOI increased directly from 24.0% for EP to 30.2% and passed the V-0 rating in the UL-94 test. However, incorporating 5 wt % POSS derivatives into EP alone to ensure that the prepared composites pass the V-0 rating of the UL-94 test has always been an extraordinarily difficult problem. Therefore, the dilemmas of poor dielectric properties, inherent flammability, and brittleness of EP were completely overcome through the successful application of POM(Mo)-POSS(ibu-Li) supramolecular nanosheets.
对于工业实际应用而言，要同时赋予环氧树脂（EP）复合材料优异的阻燃性、抑烟性、韧性和低介电常数是很困难的。在此，通过简单的一锅法，以实验室自制的含锂七异丁基倍半硅氧烷（ibu-Li-POSS）和低成本的工业显色剂HPMoO为原料，合成了独特的多面体低聚倍半硅氧烷/多金属氧酸盐（POM(Mo)-POSS(ibu-Li)）纳米片。将2 wt%的POM(Mo)-POSS(ibu-Li)纳米片加入到EP中，显著增强了纳米添加剂与EP基体之间的相容性。与EP相比，弯曲强度和冲击强度分别提高了36.2%和%78.2。因此，与现有的阻燃剂相比，POM(Mo)-POSS(ibu-Li)在提高EP韧性方面具有显著优势。介电常数和损耗明显降低，以满足EP型电子封装材料和组件日益增长的需求。值得注意的是，合成的POM(Mo)-POSS(ibu-Li)含有各种阻燃和抑烟元素，如P、Mo和Si。POM(Mo)-POSS(ibu-Li)的超低负载量（2 wt%）分别使热释放速率峰值、产烟速率峰值和CO产生速率显著降低了43.9%、40.6%和65.8%。同时，极限氧指数值从EP的24.0%直接提高到30.2%，并通过了UL-94测试中的V-0等级。然而，仅将5 wt%的POSS衍生物加入到EP中以确保制备的复合材料通过UL-94测试的V-0等级一直是一个极其困难的问题。因此，通过成功应用POM(Mo)-POSS(ibu-Li)超分子纳米片，完全克服了EP介电性能差、固有易燃性和脆性等难题。
