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A new optically active spirobifluorene-based diamine monomer, (R)-2,2′-bis(4-amino-2-trifluorom-ethylphenoxy)-9,9′-spirobifluorene, was synthesized using (R)-2,2′-dihydroxy-9,9′-spirobifluorene as starting material. The absolute stereochemistry of the chiral diamine was determined by single crystal X-ray diffraction. A series of novel chiral polyimides were prepared from the diamine with various aromatic...
The glass–rubber and sub-glass relaxation characteristics of ortho-functionalized aromatic polyimides and thermally rearranged polymers were investigated by dynamic mechanical and dielectric methods. Soluble polyimides (HAB–6FDA; APAF–ODPA) were synthesized by chemical and thermal imidization and subject to thermal rearrangement at elevated temperature. For the thermal exposure histories investigated,...
Thermal analysis and infrared spectroscopic studies were performed to investigate the strength of intermolecular interactions of the polyimides derived from 5,4′-diamino-2-phenyl benzimidazole (DAPBI) and 5,4′-diamino-2-phenyl benzoxazole (DAPBO). Polyimide films were prepared based on biphenyltetracarboxylic dianhydride (BPDA) isomers, difference of glass transition temperatures (ΔT g ) between...
Unsymmetrical and symmetrical diamine monomers containing trifluoromethyl groups, 2-trifluoromethyl-4,4′-diaminodiphenyl sulfide and 2,2′-bis(trifluoromethyl)-4,4′-diamino-diphenyl sulfide, were synthesized from 2-chloro-5-nitrobenzotrifluoride as a starting material in two steps, respectively. Diamine monomers were polymerized with PMDA, BPDA, BTDA, and ODPA using a solution imidization method with...
In this contribution the diffusion of methanol in two commercial polyimides (6FDA-ODA and Ultem ® 1000) is investigated in detail by gravimetric analysis and in-situ, time-resolved FTIR spectroscopy. Two methods of spectral data analysis are employed, namely difference spectroscopy (DS) and least-squares curve fitting (LSCF). These approaches provided complementary information about the overall...
Porous polyimides are important class of macromolecules owing to their excellent redox behaviour, efficient capture of CO 2 and H 2 gases, interesting photocatalytic properties and superior thermal and chemical stabilities. Here we describe in detail, the synthesis and gas storage properties of a series of porous polyimides (Tr-NPI, Tr-PPI, Tr-CPI, Td-PPI and Td-CPI) with various network...
A series of aromatic polyimides with pendent triphenylamine group were synthesized from equimolar mixtures of 4,4′-oxydianiline (ODA) and 4-(3,5-diaminobenzamido)triphenylamine (4), 4-(3,5-diaminobenzamido)-4′,4″-di-tert-butyltriphenylamine (t-Bu-4) or 4-(3,5-diaminobenzamido)-4′,4″-dimethoxytriphenylamine (MeO-4) with two aromatic tetracarboxylic dianhydrides (DSDA or 6FDA) via a conventional two-step...
Miscible blends of Matrimid and carboxylated polymers of intrinsic microporosity (cPIM-1) at the molecular level have been discovered. Their miscibility has been confirmed by polarized light microscopy (PLM), atomic force microscopy (AFM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The existence of hydrogen bonding promotes...
We have developed a novel route for the synthesis of high-performance bio-polyimides (PIs) microbially-derived from photo-responsive aromatic diamine 4,4′-diaminostilbene (DAS) and its reduced counterpart 4, 4′-(ethane-1,2-diyl)dianiline (EDDA). DAS and EDDA were condensed with various commercially-available dianhydrides to obtain a series of poly(amic acid)s (PAAs) and PIs which were characterized...
High temperature triggered multiple-shape memory poly(benzoxazole-co-imide)s with adjustable properties were prepared via facile random copolymerization 3,3′,4,4′-biphenyltetracarbolylic dianhydride (BPDA) with two different diamine of 4,4′-oxydianiline (ODA) and 5-amino-2-(4-aminobenzene) benzoxazole (BOA). The effect of polybenzoxazole on the molecular packing, physical properties and shape memory...
An index describing the sharpness of glass transitions is proposed in this work. This index is closely connected to thermoplasticity, which was determined as the slope of logarithmic storage modulus (log E′)–temperature curves, that is, −d log E′/dT at a point just above the Tg determined by dynamic mechanical analysis (DMA). The main purpose of this work was to obtain high-temperature polymeric materials...
Here, we report superheat-resistant polymers, poly(benzoxazole imide)s (PBOI), with very low coefficients of thermal expansion (CTE) and sufficient ductility for applications as the plastic substrates of organic light-emitting diode (OLED) displays. Diamines incorporating benzoxazole (BO) units were synthesized for this purpose. A PBOI derived from a BO-containing diamine and 3,3′,4,4′-biphenyltetracarboxylic...
Polarization-dependent refractive indices were utilized to probe the free volume and anisotropic chain orientation of several types of microporous polyimides (PIs)/copolyimides (co-PIs) based on Tröger's base (TB). The properties related to the free volume and chain orientation, such as dielectric constants and linear thermal expansion behaviors, as well as the out-of-plane thermal diffusivity (D⊥...
A newly designed carbocyclic pseudo Tröger's base diamine (CTB) monomer, 2,8-dimethyl-3,9-diamino-5,6,11,12-tetrahydro-5,11-methanodibenzo[a,e][8]annulene (CTBDA) and its isomeric analogue 2,8-dimethyl-(1,7)(4,10)(3,9)-diamino-5,6,11,12-tetrahydro-5,11-methanodibenzo[a,e][8]annulene (iCTBDA), were designed for the synthesis of microporous 6FDA-based polyimides (6FDA-CTBDA and 6FDA-iCTBDA). Both polyimides...
In the present study, the influence of filler concentration on the dynamic properties of nanocomposites based on the thermoplastic polyimide R-BAPO has been investigated by means of full-atomistic molecular dynamics simulations. The orientational mobility of chain fragments of different lengths has been studied before and after embedding of single-walled carbon nanotubes (SWCNT) into the polymer....
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