Preparation and Properties of Molecular Composite Films of Block Copolyimides Based on Rigid Rod and Semi-Flexible Segments

Oishi, Yoshiyuki; Itoya, Kazuo; Kakimoto, Masa–aki; Imai, Yoshio

doi:10.1295/polymj.21.771

Cited by 47 publications

(27 citation statements)

References 8 publications

(3 reference statements)

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“…The thermal stability, chemical resistance and the mechanical data were substantially improved. The concept of block copolymeric structures was also applied to polyimide structures based on rigid and semiflexible segments (268). An improvement of the mechanical data was found.…”

mentioning

confidence: 99%

Molecular composites for molecular reinforcement: A promising concept between success and failure

Schartel

Wendorff

1999

Polymer Engineering & Sci

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mentioning

confidence: 99%

Molecular composites for molecular reinforcement: A promising concept between success and failure

Schartel

Wendorff

1999

Polymer Engineering & Sci

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“…As is apparent from calculated from the copolyimide and solvent were almost constant, indicating that the influence of 23 on the structure of the asymmetric membrane is negligible. In contrast, 13 values as an interaction parameter between the butanol and the copolyimide depended on the copolyimide structures. In general, a large 13 indicates a low compatibility of the butanol-copolyimide interaction and a small 13 indicates the high mutual affinity of butanol and the copolyimide.…”

Section: Effect Of Phase Separation On Formation Of Asymmetric Membranementioning

confidence: 85%

“…13,14 However, little attention has been paid to preparing an asymmetric polymer membrane with an ultrathin and defectfree skin layer from the copolyimide.…”

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confidence: 99%

Gas Transport Properties of Asymmetric Block Copolyimide Membranes

2009

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We have synthesized fluorinated block copolyimides with different block chain lengths by chemical imidization in a two-pot procedure and prepared the asymmetric coployimide membranes using the dry-wet phase inversion process. The gas transport properties of the asymmetric membranes were measured using a high vacuum apparatus equipped with a Baratron absolute pressure gauge at 76 cmHg and 35 C. We demonstrated that the skin layer thicknesses and the gas transport properties of the asymmetric membranes depended on the copolyimide structures. The phase separation in the block copolyimide solution instantaneously occurred so that the skin layer of the asymmetric block copolyimide membrane became thinner than that of the asymmetric random copolyimide membrane and the gas permeance of the asymmetric block copolyimide membrane had a high value. The apparent skin layer thickness of the asymmetric block coployimide membrane was 230 nm. Polymer membranes are considered an effective technology for the separation of gaseous mixtures due to their high separation efficiency, low operating costs, and simple operation. The development of novel polymer membranes with even higher gas permeabilities and selectivities has received much attention.1,2 The gas permeation through a polymer membrane not only is a function of the chemical structure of the polymers but also is determined by the morphology or the domain structure formed on the membrane. Particularly, in the case of the block copolymers or miscible blends of polymers, their gas permeations are affected by the domain size of microor nanometers formed on the membrane or the extent of the interactions between the component polymers. [3][4][5] Recently, the gas transport properties of block copolymers based on a rubbery polymer have been investigated for acid gas removal from natural gas, recovery of CO 2 from flue gases, and the removal of CO 2 from gas mixtures with hydrogen. 6 However, it is difficult to prepare ultrathin membranes from the block copolymers based on rubbery polymers, because these copolymers do not have sufficient mechanical properties.Polyimide as a glassy polymer has been recognized as one of the most promising potential candidates for a gas separation material because of the high gas selectivity and excellent mechanical properties for preparing the ultrathin membranes. [7][8][9] In general, the polyimide is obtained from a precursor condensed from two monomers with dianhydride and diamine moieties, and the gas transport properties through the polyimide membrane have been investigated. Although the gas transport properties of copolyimide membranes were reported in some papers, 10-12 most of the copolyimides were random copolymers and there has been little attention given to the gas transport properties of block copolyimide membranes.Of course, there are a few papers concerning block copolyimides, which reported the effects of the monomer structure and the length of the block chains on the thermal and chemical stability or mechanical properties of the copol...

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“…For example, the Tg of 6FDA‐TFMB could be increased by 30 °C without any sacrifice of transparency, if linear, rigid segment of PMDA is incorporated into the molecular chain of 6FDA‐TFMB PI by copolymerization . Monomer sequence in the PI chain also control the compatibility between chains, thereby leading to different film microstructures, which originates various properties . By comparison of the different copolymerization methods between BPDA, t‐CHDA and 2,5(2,6)‐bis(aminomethyl) bicycle[2.2.1]‐heptane, it is found that block method is more effective to minimize the CTE and enhance the film strength, meanwhile maintaining high transparency, which may be attributed to the micro‐phase separation .…”

Section: Recent Design Approaches To Prepare Cpismentioning

confidence: 99%

“…[195] Monomer sequence in the PI chain also control the compatibility between chains, thereby leading to different film microstructures, which originates various properties. [98,[196][197][198] By comparison of the different copolymerization methods between BPDA, t-CHDA and 2,5(2,6)-bis(aminomethyl) bicycle[2.2.1]-heptane, it is found that block method is more effective to minimize the CTE and enhance the film strength, meanwhile maintaining high transparency, which may be attributed to the micro-phase separation. [98,199] The CBDA/AB-TFMB PI system (Scheme 16) offers no chemical imidization (CI) process compatibility because of its poor solubility.…”

Section: Synthesis Of Colorless Polyimides Through Copolymerizationmentioning

confidence: 99%

Recent Trends on Transparent Colorless Polyimides with Balanced Thermal and Optical Properties: Design and Synthesis

Tapaswi

2019

Macro Chemistry & Physics

164

155

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Recently, colorless and transparent plastic substrates with high glass transition temperature and suitable thermo‐mechanical properties are in high demand in optoelectronic device industries, due to their various optical applications. Colorless polyimides (CPIs) exhibit both high thermo‐mechanical stability as well as high transparency that are suitable for optoelectronic applications. The most recent (2010–2018) developments on CPIs, in terms of design and synthesis of new monomers and their effects on the thermo‐optical properties of the obtained CPIs, are reviewed in this article.

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Preparation and Properties of Molecular Composite Films of Block Copolyimides Based on Rigid Rod and Semi-Flexible Segments

Cited by 47 publications

References 8 publications

Molecular composites for molecular reinforcement: A promising concept between success and failure

Molecular composites for molecular reinforcement: A promising concept between success and failure

Gas Transport Properties of Asymmetric Block Copolyimide Membranes

Recent Trends on Transparent Colorless Polyimides with Balanced Thermal and Optical Properties: Design and Synthesis

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