Constitutionally isomeric alicyclic polyimides: Origin of siteselectivity in the reaction of unsymmetrical dianhydride and structure‐derived difference in physical properties

Choi, Ji-Young; Shirai, Kazuaki; Takayama, Tadatoshi; Akagawa, Kengo; Kudo, Kazuaki

doi:10.1002/pola.26231

Cited by 3 publications

(1 citation statement)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Aromatic protons are observed at 7–9 ppm. The difference between 8.0 and 8.4 ppm in the 1 H NMR spectrum of PAA‐NMP and PAA‐DMSO can be reasonably attributed to the different sequential structure . The peaks between 10.3 and 10.8 ppm arise from protons of amide groups.…”

Section: Resultsmentioning

confidence: 86%

Control of Head/Tail Isomeric Structure in Polyimide and Isomerism‐Derived Difference in Molecular Packing and Properties

Luo

Dai

Yao

et al. 2017

Macromol. Rapid Commun.

View full text Add to dashboard Cite

paid more and more attention by other researchers. [14][15][16][17][18] The diamine, PABZ, is an unsymmetrical heterocyclic diamine, and the charge density values of head and tail amino groups were calculated by Material Studio 4.0 in our previous paper, [19] as shown in Figure 1 The charge density of amino group adjacent to benzimidazole unit (head amino group) is larger than that of amino group adjacent to benzene ring (tail amino group). [19] It means that head amino group is more reactive than tail amino group. Thus, when PABZ was reacted with dianhydride, the sequence isomerism of PAA would arise because of the regularity of head-head (HH), headtail (HT), and tail-tail (TT) bonding sequence. Moreover, During the study of solubility of PABZ in different polar aprotic solvents, we found that N-methyl-2-pyrrolidone (NMP) and dimethylacetamide (DMAC) are poor solvents for PABZ, while dimethyl sulfoxide (DMSO) is a good solvent for PABZ. In this paper, based on this unique site-selective reactivity of PABZ and the solubility of PABZ in different solvent, sequence isomers of PAAs and corresponding PIs with different head/tail bonding sequence were first synthetized and the considerable differences between them in crystalline ability and physical properties were studied. Experimental SectionMaterials, methods, analysis, and additional experimental data are supplied in the Supporting Information. Results and Discussion Model Study on the Site-selective Reactivity of PABZIt is found that DMSO is good solvent for PABZ while NMP is poor solvent for PABZ, as shown in Figure S1 (Supporting Information). Two model reactions were designed to study the site-selective reactivity of PABZ. The phthalic anhydride and PABZ were added into different solvents and the ratio of anhydride and amino groups was 1:2. In model reaction 1, PABZ was completely dissolved in DMSO and then equimolar phthalic

show abstract

Section: Resultsmentioning

confidence: 86%

Control of Head/Tail Isomeric Structure in Polyimide and Isomerism‐Derived Difference in Molecular Packing and Properties

Luo

Dai

Yao

et al. 2017

Macromol. Rapid Commun.

View full text Add to dashboard Cite

show abstract

Sequence‐Dependent Self‐Assembly of Chiral Polyimides

Yan

Kang

Bian

et al. 2017

Chemistry An Asian Journal

View full text Add to dashboard Cite

Sequence-defined chiral polyimides comprising identical asymmetric diamine monomers arranged in different directions along the main chain were designed and prepared. These new sequence-defined polymers exhibit sequence-dependent self-assembly behaviors and responses to ibuprofen enantiomers, as revealed by their chiroptical spectra and gelation properties. For the first time, the self-assembly of polymers and their interactions with guest molecules have been successfully controlled by means of the directional arrangement of the monomers in their polymer backbones.

show abstract

Soluble Polyimides Bearing (cis, trans)-Hydrogenated Bisphenol A and (trans, trans)-Hydrogenated Bisphenol A Moieties: Synthesis, Properties and the Conformational Effect

Wang

Hou

et al. 2019

Polymers

View full text Add to dashboard Cite

In this work, hydrogenated bisphenol A (HBPA) based dinitro mixed isomers (1a′ and 1a) were synthesized and separated via vacuum distillation under the monitor of DSC and 1H NMR. Corresponding diamines (2a′ and 2a) were separately polycondensed with five commercial dianhydrides via a two-step thermal imidization to obtain PI-(1′-5′) and PI-(1-5). All the polyimides could afford flexible, tough, and transparent films, and most of them were readily soluble not only in common polar solvents like DMAc, but also in low boiling point solvents such as chloroform. 1H NMR spectra of the polyimides demonstrated that HBPA moiety showed no conformation changes during the preparation of polymers. For a given dianhydride, PI-(1-5) exhibited better thermal stability than that of PI-(1′-5′), this can be attributed that the equatorial, equatorial C–O in PI-(1-5) promoted denser and more regular molecular chain stacking, as can be evidenced by the WAXD and geometric optimization results. Additionally, when the dianhydride was ODPA, BPADA or 6FDA, no apparent difference was found in either the transmittance or solubility between two series of polyimides, which could be attributed that twisted and flexible ether linkages, as well as bulky substituents, led to the “already weakened” inter- and intramolecular CT interaction and cohesive force. However, when it came to rigid and stiff dianhydride, e.g., BPDA, PI-3′ took an obvious advantage over PI-3 in transmittance and solubility, which was possibly owed to the larger molecular chain d-spacing imparted by equatorial, axial C–O. An overall investigation of PI-(1′-5′) and PI-(1-5) on aspects of thermal, mechanical, morphological, soluble and optical performance values was carried out, and the conformation effects of HBPA isomers on the properties of two series of polyimides were discussed in detail.

show abstract

Constitutionally isomeric alicyclic polyimides: Origin of siteselectivity in the reaction of unsymmetrical dianhydride and structure‐derived difference in physical properties

Cited by 3 publications

References 30 publications

Control of Head/Tail Isomeric Structure in Polyimide and Isomerism‐Derived Difference in Molecular Packing and Properties

Control of Head/Tail Isomeric Structure in Polyimide and Isomerism‐Derived Difference in Molecular Packing and Properties

Sequence‐Dependent Self‐Assembly of Chiral Polyimides

Soluble Polyimides Bearing (cis, trans)-Hydrogenated Bisphenol A and (trans, trans)-Hydrogenated Bisphenol A Moieties: Synthesis, Properties and the Conformational Effect

Contact Info

Product

Resources

About