Characterization and water vapor sorption property of ABA-type triblock copolymers derived from polyimide and poly(methyl methacrylate)

Abstract

The characterization of ABA-type triblock copolymer films derived from polyimide (PI) macroinitiator and poly(methyl methacrylate) (PMMA) synthesized by atom transfer radical polymerization was investigated by focusing on different block lengths of PMMA. The hydrophobic property tends to increase with increasing PMMA content in the triblock copolymers, while the PMMA blocks enhance the charge transfer interaction between the PI segments. The water vapor sorption measurement of triblock copolymers was determined at 35 • C. The water vapor solubility of triblock copolymers tends to decrease with increasing PMMA content. In addition, linear correlations were observed between the solubility and polymer-free volume and polymer molecular polarity in triblock copolymers as well as in other conventional polymer families. According to Zimm−Lundberg analysis, the PMMA block segments in the triblock copolymers accelerate water vapor clustering due to the high mobility of PMMA. The mobility of PMMA block segments strongly affected not only physical properties but also the water vapor solubility of the triblock copolymers. The ABA triblock copolymerization composed of PI and PMMA is one of the effective ways to improve the hydrophobic property.

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.…”

Photoelectric properties of ABA‐type triblock copolymers designed using fluorine‐containing polyimide macroinitiators with polyhedral oligomeric silsesquioxane

“…6FDA‐TeMPD (MEPOSS content 0 mol%) , poly(MEPOSS) (MEPOSS content 100 mol%) , and various 6FDA‐TeMPD/MEPOSS triblock copolymers (MEPOSS content 17, 43, and 79 mol%) were synthesized according to the literature procedure. 1 H NMR (JNM‐ECA500; JEOL Ltd., Tokyo, Japan) and Fourier transform infrared (FTIR) spectroscopy (FT‐IR 460+; JASCO Co., Tokyo, Japan) analyses confirmed the chemical structures of these polymers, as shown in Fig.…”

“…ATRP is an in situ method that allows good control of both the molecular weight and molecular distribution. Additionally, ATRP is the free‐living radical polymerization method most commonly used for polymerizing a wide range of monomers under mild reaction conditions . Therefore, the ABA‐type triblock copolymer was expected to possess a structure with nanoscale phase separation and to produce a transparent film for high dispersion over the visible light region.…”

Phototransparency and water vapor sorption properties of ABA‐type triblock copolymers derived from 6FDA‐TeMPD and poly(2‐methyl‐2‐adamantylmethacrylate)

“…PI has lower coloration by charge‐transfer (CT) complex than other polyimides because of its high free volume. However, result of water vapor sorption measurements have revealed the behavior of swelling and plasticization in PI with interaction of water molecules . Thus, the degradation of phototransparency and mechanical strength of PI used for a long time in a humid atmosphere is of concern.…”

“…In this study, we focused on the development of material that is compatible with phototransparency and is resistant to water vapor because these features are important in flexible‐display applications. Our research group has previously reported that ABA‐type triblock copolymer membranes derived from PI and poly(methyl methacrylate) (PMMA) have low water interaction, which effectively inhibits the influence of water vapor to membrane structures by water vapor sorption measurement . However, the phototransparency of block copolymer was found to decrease compared with PI because of the formation of a phase‐separation structure between two components by triblock copolymerization.…”