低介电常数聚酰亚胺/多金属氧酸盐复合薄膜的制备及其性能

Preparation and Properties of Low Dielectric Constant Polyimide/ Polyoxometalates Hybrid Films

以带环氧官能团的3-环氧丙氧基三甲基硅烷(KH560)作为改性剂在酸性MeCN/H2O混合溶液中和多金属氧酸盐K8SiW11O39进行反应,制得了硅烷改性的多金属氧酸盐有机杂化物SiW11KH560,红外光谱、XPS等分析结果表明KH560与K8SiW11O39发生了反应。将改性后的K8SiW11O39添加到均苯四甲酸酐-二苯醚二胺的聚酰胺酸溶液中,热酰亚胺化制备了聚酰亚胺/多金属氧酸盐复合薄膜。EDS能谱分析表明多金属氧酸盐颗粒在聚酰亚胺基体中呈均匀分布,当复合薄膜中多金属氧酸盐有机杂化物SiW11KH560含量达到20%(wt)时,复合薄膜的介电常数从3.29降低至2.9。此外,随着SiW11KH560添加量的增加,复合薄膜的储能模量也显著提高,而复合薄膜的热性能没有受到严重影响。

A silane-modified mono-lacunary Keggin-type polyoxometalate SiW11KH560 was obtained by reaction of （3-Glycidoxypropyl）trimethoxysilane （KH560） with K8SiW11O39（SiW11） in acidic MeCN/H2O mixed solutions. FT-IR and XPS spectrums demonstrate that KH560 is grafted onto the polyoxometalate. Then the modified polyoxometalate was added into the pyromellitic dianhydride （PMDA）-4,4′-oxydianiline-（ODA） poly（amic acid） solution, and the poly（amic acid） solution were thermally imidized to form polyimide/polyoxometalate composites. The EDS （W-mapping） studies on the composite films reveal that the polyoxometalate clusters are well dispersed in the polyimide matrix. The incoporation of SiW11KH560 into polyimide reduces the dielectric constant of the latter from 3.29 to2.9 when 20 %（wt） of SiW11KH560 is used. Besides, the addition of the modified polyoxometalate into polyimide increases the storage modulus of polyimide without severely affecting its thermal properties.