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Polyimide Nanocomposites (polyimide + nanocomposite)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Polyimide nanocomposites: Comparison of their properties with precursor polymer nanocomposites

POLYMER ENGINEERING & SCIENCE, Issue 12 2001
Jin-Hae Chang
A precursor poly(amic acid) was obtained by solution polymerization of pyromellitic dianhydride and benzidine in N, N-dimethylacetamide. Poly(amic acid)/Organoclay hybrids were prepared by the solution intercalation method with dodecylamine-montmorillonite. A polyimide hybrid was obtained from poly(amic acid) hybrid by heat treatment at various temperatures. The film type polyimide hybrids showed better thermal properties than poly(amic acid) hybrids. Also, the thermal stability of the two polymer hybrids were enhanced linearly with increasing clay content from 0 to 8 wt%. Tensile properties and gas barriers of the hybrids, however, were enhanced remarkably compared to pristine polymers. Intercalations of the polymer chains in clar were examined through wide angle X-ray diffraction (XRD) and electron microscopy (SEM and TEM). Transmission electron microscopy revealed that a partially exfoliated structure had been obtained from polyimide/organo-clay hybrids. [source]

Prediction of the effective dielectric constant in SWNT polyimide nanocomposites using the Bruggemann model

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2009
Ricardo PérezArticle first published online: 27 APR 200
Abstract The Bruggemann model is used in this work to predict the effective dielectric constant of two kinds of single-wall carbon nanotube (SWNT) polyimide nanocomposites. Electrical conductivity and dielectric constant exhibit a dramatic enhancement at low content of SWNT fillers with a percolation threshold at 0.06 vol %. Results of the Bruggemann model are compared with the experimental values of the dielectric constant in CP2/SWNT and ,CN/SWNT polyimide nanocomposites. A reasonable agreement for SWNT contents under the percolation threshold and a SWNT dielectric constant of 2000 was found between the Bruggeman model modified by Giordano and the experimental values. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]

A simple approach toward low-dielectric polyimide nanocomposites: Blending the polyimide precursor with a fluorinated polyhedral oligomeric silsesquioxane

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 18 2008
Yun-Sheng Ye
Abstract This article describes a new and simple method for preparing polyimide nanocomposites that have very low dielectric constants and good thermal properties: simply through blending the polyimide precursor with a fluorinated polyhedral oligomeric silsesquioxane derivative, octakis(dimethylsiloxyhexafluoropropyl) silsesquioxane (OF). The low polarizability of OF is compatible with polyimide matrices, such that it can improve the dispersion and free volume of the resulting composites. Together, the higher free volume and lower polarizability of OF are responsible for the lower dielectric constants of the PI-OF nanocomposites. This simple method for enhancing the properties of polyimides might have potential applicability in the electronics industry. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6296,6304, 2008 [source]

Efficient dispersion of multi-walled carbon nanotubes by in situ polymerization

POLYMER INTERNATIONAL, Issue 5 2007
Nantao Hu
Abstract Multi-walled carbon nanotube (MWNT)-reinforced polyimide nanocomposites were synthesized by in situ polymerization of monomers in the presence of acylated MWNTs. The acyl groups associated with the MWNTs participated in the reaction through the formation of amide bonds. This process enabled uniform dispersion of MWNT bundles in the polymer matrix. The resultant MWNT,polyimide nanocomposite films were optically transparent with significant mechanical enhancement at a very low loading (0.5 wt%). Evidence has been obtained for improved interactions between the nanotubes and the matrix polymer. Copyright © 2006 Society of Chemical Industry [source]