Synthesis, characterization and properties of polyimides derived from a symmetrical diamine containing bis-benzimidazole rings

Liu, Junpeng; Zhang, Qinghua; Xia, Qingming; Xu, Qian

doi:10.1016/j.polymdegradstab.2012.03.010

Cited by 83 publications

(41 citation statements)

References 36 publications

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“…The possible reason for the extensive improvement is inferred as follows. It is well known that the mechanical properties of PI fibers are closely dependent on the intrinsic viscosities, intermolecular interaction, and rigidity of polymer backbone, molecular packing, and structural defects [24][25][26][27]. Currently, the intrinsic viscosities of PAA solutions range from 1.80 to 2.32 dL g -1 without the ordered regularity, implying that the enhancement in mechanical properties is not mainly affected by the intrinsic viscosity.…”

Section: Mechanical Properties Of the Co-pi Fibersmentioning

confidence: 99%

Structures and properties of polyimide fibers containing ether units

et al. 2015

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Copolyimide (co-PI) fibers containing 4,4 0 -oxydiphthalic anhydride (ODPA) moiety into the 3,3 0 ,4,4 0 -biphenyltetracarboxylic dianhydride (BPDA)/p-phenylenediamine backbone were prepared via a two-step wet-spinning method. The processability and mechanical properties were improved significantly after the incorporation of ODPA, and the fibers exhibited an optimum tensile strength of 10.94 cN dtex -1 and modulus of 470.52 cN dtex -1 with elongation of 2.75 % at a BPDA/ODPA molar ratio of 7/3. Two-dimensional wide angle X-ray diffraction indicated that highly oriented structures and ordered molecular packing regions were formed in the fibers. Two-dimensional small angle X-ray scattering revealed that the incorporation of ODPA resulted in the reduction in radius, length, misorientation, and internal surface roughness of the microvoids in the fibers simultaneously, which was supposed to be mainly dominated for the drastically improved mechanical properties of PI fibers. Moreover, the co-PI fibers exhibited excellent thermal and thermal-oxidative stability, and the 5 % weight loss temperature was above 572 and 535°C under nitrogen and air, respectively.

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Section: Mechanical Properties Of the Co-pi Fibersmentioning

confidence: 99%

Structures and properties of polyimide fibers containing ether units

et al. 2015

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“…However, no obvious deflection showing a glass transition was observed for any of the CPAIs in the DSC thermograms. This trait may be due to both the low thermal response during the transition and the high packing density of the CPAIs (14,15). The rigidrod nature of the polymer chains with a combination of polar multi-cyclic imides and linear adipamide residues could be the base of such function.…”

Section: Polymer Propertiesmentioning

confidence: 99%

Highly compact co-poly(amide-imide)s from polycondensation of an imide-modified derivative of l-aspartic acid

2014

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The direct polycondensation of a monomer derived from l-aspartic acid together with adipic acid as a modifier co-monomer with aromatic diamines was studied to synthesize co-poly(amide-imide)s (CPAIs). The relative reactivity of the co-monomers and the manner of their insertion into polymer chains were evaluated using a model reaction and 1 H NMR spectroscopy, respectively. The synthesized polymers depicted optical rotations similar to those of the monomer precursor and inherent viscosities in the range of 0.13-0.95 dl/g. Thermal stability and behavior as well as the weight-loss pattern of the CPAIs were studied by thermo-analytical techniques (thermogravimetric analysis-differential thermal analysis, dynamic mechanical thermal analysis and differential scanning calorimetry). Onset decomposition temperatures > 300°C and carbonization residues of more than 50% at 600°C were detected for the treated polymers. Almost all of the copolyamides were noncrystalline solids, as illustrated in the X-ray diffraction patterns, and had good levels of solubility in a variety of polar organic solvents. These polymers could afford transparent and flexible to brittle films in solution casting on glass plates. Scanning electron microscopy on the polymer films showed a uniform and continuous morphology, indicating good film forming ability.

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“…Wu et al designed an effective route to synthesize semi‐aromatic PIs containing polyhedral oligomeric silsesquioxane (POSS) units in their main chains, exhibiting a low dielectric constant, high thermal stability and good solubility, but the mechanical properties were not much higher than virgin PI material. Zhang and colleagues successfully synthesized a novel series of PIs containing bis‐benzimidazole rings in the backbone. The PI films had outstanding thermal stability but the mechanical properties were not markedly increased.…”

Section: Introductionmentioning

confidence: 99%

Preparation of polyimide/siloxane‐functionalized graphene oxide composite films with high mechanical properties and thermal stability via in situ polymerization

Zhang

Chen

et al. 2015

Polymer International

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An effective approach to prepare polyimide/siloxane‐functionalized graphene oxide composite films is reported. The siloxane‐functionalized graphene oxide was obtained by treating graphene oxide (GO) with 1,3‐bis(3‐aminopropyl)‐1,1,3,3‐tetra‐methyldisiloxane (DSX) to obtain DSX‐GO nanosheets, which provided a starting platform for in situ fabrication of the composites by grafting polyimide (PI) chains at the reactive sites of functional DSX‐GO nanosheets. DSX‐GO bonded with the PI matrix through amide linkage to form PI‐DSX‐GO films, in which DSX‐GO exhibited excellent dispersibility and compatibility. It is demonstrated that the obvious reinforcing effect of GO to PI in mechanical properties and thermal stability for PI‐DSX‐GO is obtained. The tensile strength of a composite film containing 1.0 wt% DSX‐GO was 2.8 times greater than that of neat PI films, and Young's modulus was 6.3 times than that of neat PI films. Furthermore, the decomposition temperature of the composite for 5% weight loss was approximately 30 °C higher than that of neat PI films. © 2015 Society of Chemical Industry

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Synthesis, characterization and properties of polyimides derived from a symmetrical diamine containing bis-benzimidazole rings

Cited by 83 publications

References 36 publications

Structures and properties of polyimide fibers containing ether units

Structures and properties of polyimide fibers containing ether units

Highly compact co-poly(amide-imide)s from polycondensation of an imide-modified derivative of l-aspartic acid

Preparation of polyimide/siloxane‐functionalized graphene oxide composite films with high mechanical properties and thermal stability via in situ polymerization

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