A low dielectric constant polyimide/polyoxometalate composite

作者：Tan, Lin; Liu, Shumei; Zeng, Fang; Zhang, Shukun; Zhao, Jianqing; Yu, Yin-e

来源：Polymers for Advanced Technologies, 2011, 22(2): 209-214.

DOI：10.1002/pat.1517

• dielectric constants
• dielectric loss
• polyoxometalate
• polyimide
• organic/inorganic hybrids

A silane-modified mono-lacunary Keggin-type polyoxometalate (POM), (Bu4N)(4)[SiW11O39{(CH2=CH-Si)(2)O}] (SiW11-CH=CH2), was obtained by reaction of vinyltrimethoxysilane with K-8(SiW11O39) in acidic MeCN/H2O mixed solutions. Then, the modified polyoxometalate was physically blended with the pyromellitic dianhydride (PMDA)-4,4'-oxydianiline (ODA) poly(amic acid) and the blends were thermally imidized to form polyimide/polyoxometalate composites. The X-ray diffraction (XRD) analysis indicates that the polyoxometalate clusters cannot form crystalline structures in the composite, suggesting that the blending leads to improved compatibility between the polymer matrix and the modified polyoxometalate. The EDS (W-mapping) studies on the composite films reveal that the polyoxometalate clusters are well dispersed in the polyimide matrix. The physical incorporation of modified POM into polyimide remarkably reduced the dielectric constant of the latter from 3.29 to 2.05 when 20 wt% of SiW11-CH=CH2 was used. Besides, the addition of the modified POM into polyimide increased the storage modulus of polyimide without severely affecting its thermal properties.

• 单位
  华南理工大学