Department of Polymer Science and Engineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
J Phys Chem B. 2013 Feb 28;117(8):2505-15. doi: 10.1021/jp310021r. Epub 2013 Feb 13.
In this work, the dielectric properties of immiscible polystyrene (PS)/poly(vinylidene fluoride) (PVDF) blends are tuned by selectively localizing carbon black (CB) nanoparticles in different phases. The PS/PVDF blends have a wide window of cocontinuity (ca. 30-80 vol % in terms of the volume fraction of PS component (v(PS))). The selective localization of CB nanoparticles is achieved by using the masterbatch process during melt mixing. For the volume ratio PS/PVDF 1/1 and the volume fraction of CB nanoparticles (v(CB)) below but close to the percolation threshold (v(c)(CB)), the selective localization of CB nanoparticles in PVDF phase produces higher dielectric constant (ε) than that in PS phase, whereas the ε of the ternary mixtures without selective localization of fillers is in the middle. For the volume ratios PS/PVDF 1/2 and 2/1, the selective location of CB nanoparticles in different phases can be used to easily tune the system from conductive to insulating or inverse, which might have potential applications in industry. The fillers are found to be "fixed" in the masterbatch of PS or PVDF component and there is no migration of the fillers to another phase occurring during the further mixing process for the mixing time up to 30 min. Furthermore, the addition of CB nanoparticles to the polymer matrix is found to induce the brittle-ductile transition in the system and increase the compatibility between the immiscible PS and PVDF components, which should benefit the mechanical properties.
在这项工作中，通过选择性地将碳黑（CB）纳米粒子定位在不同相中，调节了不混溶的聚苯乙烯（PS）/聚偏二氟乙烯（PVDF）共混物的介电性能。PS/PVDF 共混物具有宽的共连续窗口（约 30-80 体积%，以 PS 组分的体积分数（v(PS))表示）。通过在熔融混合过程中使用母料工艺，可以实现 CB 纳米粒子的选择性定位。对于 PS/PVDF 的体积比 1/1 和低于但接近渗流阈值（v(c)(CB))的 CB 纳米粒子的体积分数（v(CB))，CB 纳米粒子在 PVDF 相中选择性定位会产生比 PS 相更高的介电常数（ε），而没有选择性定位填充剂的三元混合物的 ε 在中间。对于 PS/PVDF 的体积比 1/2 和 2/1，不同相中的 CB 纳米粒子的选择性定位可用于轻松地将系统从导电调至绝缘或相反状态，这可能在工业中有潜在应用。发现填料在 PS 或 PVDF 组分的母料中“固定”，并且在进一步混合过程中填料没有迁移到另一个相中，混合时间长达 30 分钟。此外，将 CB 纳米粒子添加到聚合物基质中会诱导系统发生脆-韧转变，并增加不混溶的 PS 和 PVDF 组分之间的相容性，这应该有利于机械性能。
