Polyimide/carbon black（PI/CB） nanocomposite films were fabricated via the direct ball-milling method with poly（amic acid）（PAA）, the precursor of PI, as an in situ formed impurity-free dispersant. FTIR and Raman ...Polyimide/carbon black（PI/CB） nanocomposite films were fabricated via the direct ball-milling method with poly（amic acid）（PAA）, the precursor of PI, as an in situ formed impurity-free dispersant. FTIR and Raman spectral results reveal that, besides physical adsorption, chemical grafting of PAA chains onto the CB surface occurs during the ball-milling process. Comparative studies show that introduction of various commercial dispersants improves the dispersion of CB. However, the mixtures exhibit poor reproducibility, unstable electrical properties, and decreased tensile strength; these issues may be attributed to interfacial pollution brought about by differences in the chemical structures of the dispersant and the matrix. The impurity-free dispersant is effective not only in ensuring the uniform dispersion of CB particles but also in enhancing filler-matrix interfacial adhesion. High-molecular weight PAA chains are effective reagents for impurity-free modification and can therefore be used to improve the electrical and mechanical properties of the resultant composite.展开更多
基金supported by the National Basic Research Program of China(No.2013CB035505)the National Natural Science Foundation of China(No.51503066)+2 种基金Shanghai Sailing Program(No.14YF1404900)China Postdoctoral Science Foundation(No.2015M571502)the Fundamental Research Funds for the Central Universities
文摘Polyimide/carbon black（PI/CB） nanocomposite films were fabricated via the direct ball-milling method with poly（amic acid）（PAA）, the precursor of PI, as an in situ formed impurity-free dispersant. FTIR and Raman spectral results reveal that, besides physical adsorption, chemical grafting of PAA chains onto the CB surface occurs during the ball-milling process. Comparative studies show that introduction of various commercial dispersants improves the dispersion of CB. However, the mixtures exhibit poor reproducibility, unstable electrical properties, and decreased tensile strength; these issues may be attributed to interfacial pollution brought about by differences in the chemical structures of the dispersant and the matrix. The impurity-free dispersant is effective not only in ensuring the uniform dispersion of CB particles but also in enhancing filler-matrix interfacial adhesion. High-molecular weight PAA chains are effective reagents for impurity-free modification and can therefore be used to improve the electrical and mechanical properties of the resultant composite.
