Solid and thermal properties of ABA‐type triblock copolymers designed using difunctional fluorine‐containing polyimide macroinitiators with methyl methacrylate

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

Dependence of the dielectric constant on the fluorine content and porosity of polyimides

“…Void fabrication allows the diffusion of air into the polymer matrices; because air has a dielectric constant of 1, the dielectric constant is lowered. One method for inducing porosity in the PI structure involves the preparation of block copolymers consisting of thermally stable and thermally labile blocks, the latter being the dispersed phase 13–15. Foam formation is then effected by the thermolysis of the thermally labile block, which leaves pores with sizes and shapes corresponding to the initial copolymer morphology 6, 12–14, 16…”

Synthesis and gas permeability of ABA-type triblock copolymers derived from fluorine-containing polyimide with polyhedral oligomeric silsesquioxane

“…The use of ABA‐type triblock copolymers for functionalizing polymers was reported in a previous study . ABA‐type triblock copolymers present high dispersion among their components.…”

“…PI and PI macroinitiator (PI‐M) were synthesized according to the methods described in previous studies . In this study, the molar ratio in the feed [6FDA]/[TeMPD]/[APA] for PI‐M polymerization was set to 100/97/6 to increase film formability via increase in molecular weight.…”

“…Polycarbonates, polysulfones and polyimides (PIs) have attracted significant research attention as film‐based CO 2 separation materials, and aromatic PIs exhibiting excellent thermal resistance, durability and gas separation performance have been investigated for their potential applications. 4,4'‐(Hexafluoroisopropylidene)diphthalicanhydride (6FDA) based PI composed of 2,3,5,6‐tetramethyl‐1,4‐phenylenediamine (TeMPD), in particular, shows high gas permeability because of the bulky CF 3 group of 6FDA and the tetramethyl group of TeMPD.…”

Gas transport and optical properties of ABA-type triblock copolymers designed using fluorine-containing polyimide macroinitiators with methyl methacrylate

“…ATRP is the most commonly used free‐living radical polymerization for polymerizing a wide range of monomers under mild reaction conditions. The ATRP technique is useful for obtaining well‐defined polymers with various architectures, such as block and graft polymers, as well as allowing the control of both the molecular weight and molecular distribution of the polymers . The 6FDA‐TeMPD and PMMA polymers are immiscible.…”