Solid and thermal properties of ABA‐type triblock copolymers designed using difunctional fluorine‐containing polyimide macroinitiators with methyl methacrylate |
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Authors: | Sou Miyata Kazuhito Yoshida Hayato Shirokura Mikihiro Kashio Kazukiyo Nagai |
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Affiliation: | 1. Department of Applied Chemistry, Meiji University, 1‐1‐1 Higashi‐mita, Tama‐ku, Kawasaki 214‐8571, Japan;2. Reseach Laboratory, Lintec Co., 5‐14‐42 Nishiki‐cho, Warabi 335‐0005, Japan |
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Abstract: | BACKGROUND: ABA‐type poly(methyl methacrylate) (PMMA) and fluorine‐containing polyimide triblock copolymers are potentially beneficial for electric materials. In the work reported here, triblock copolymers with various block lengths were prepared from fluorine‐containing difunctional polyimide macroinitiators and methyl methacrylate monomer through atom‐transfer radical polymerization. The effects of structure on their solid and thermal properties were studied. RESULTS: The weight ratios of the triblock copolymers derived using thermogravimetric analysis were shown to be almost identical to the ratios determined using 1H NMR. The solid properties (film density and maximum d‐spacing value) and thermal properties (glass transition and thermal expansion) were shown to be strongly dependent on the weight ratios of both PMMA and polyimide components. Furthermore, a porous film, which showed a lower dielectric constant of 2.48 at 1 MHz, could be prepared by heating a triblock copolymer film to induce the thermal degradation of the PMMA component. CONCLUSION: The use of the polyimide macroinitiator was useful in the preparation of ABA‐type triblock copolymers to control each block length that influences the solid and thermal properties. Additionally, the triblock copolymers have great potential in preparing porous polyimides in the application of electric materials as interlayer insulation membranes of large‐scale integration. Copyright © 2009 Society of Chemical Industry |
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Keywords: | polyimides block copolymers atom‐transfer radical polymerization (ATRP) thermal properties dielectric constant |
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