Aromatic thermotropic liquid crystalline polymers from 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene

Tamai, Shoji; Ohkawa, Yasuhiro; Yamaguchi, Akihiro

doi:10.1016/s0032-3861(96)00974-3

Cited by 11 publications

(9 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Poly(amic acid) PAA sample for the study was obtained from Mitsui Chemicals, Japan. The PAA was synthesized from 1,2,4,5‐benzentetracarboxylic dianhydride (PMDA) and 1,3‐bis[4‐(4′‐aminophenoxy)cumyl]benzene (BACB) 10,11. Following monomer polymerization in N , N ‐dimethylacetamide (DMAc), PAA was precipitated in excessive methanol, and then washed in methanol several times to extract the residual DMAc.…”

Section: Experimental Partmentioning

confidence: 99%

Thermal Imidization of the Precursor of a Liquid Crystalline Polyimide

Pramoda

Liu

Chung

2002

Macro Materials & Eng

View full text Add to dashboard Cite

Imidization of the precursor of a liquid crystalline polyimide was investigated using modulated differential scanning calorimetry (MDSC), Fourier transform infrared (FTIR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), and thermogravimetric analyzer (TGA) coupled to FTIR (TG‐IR). The FTIR study revealed that the rate and degree of imidization are functions of curing temperature and time. Imidization proceeds in two stages under isothermal condition. The initial weight loss up to 250 °C as observed from TGA was due to thermal cyclization, i.e., imidization process. The XPS analysis shows that the poly(amic acid) has two nitrogen 1s species at 400.3 and 399.2 eV possibly due to the isomerism of the dianhydride carbonyl, while liquid crystalline polyimide shows only a single nitrogen 1s species at 400.8 eV due to imide species.PLM micrograph of PAA (at 280 °C) after imidization.magnified imagePLM micrograph of PAA (at 280 °C) after imidization.

show abstract

Section: Experimental Partmentioning

confidence: 99%

Thermal Imidization of the Precursor of a Liquid Crystalline Polyimide

Pramoda

Liu

Chung

2002

Macro Materials & Eng

View full text Add to dashboard Cite

show abstract

“…The detailed synthesis procedures are described in the literature. [27][28][29] The chemical structure of this polyimide is shown in Scheme 1. The inherent viscosity was found to be 0.6 dL/g in the 9 : 1 mixture of 4-chlorophenol and phenol at 308K.…”

Section: Experimental Materialsmentioning

confidence: 99%

“…[25][26][27][28][29][30] Asanuma et al 27 reported that the T g was not detectable and two melting peaks were found at 270°C and 300°C in the first heating and at 280°C and 300°C in the second heating with a heating rate of 16°C/min. Tanaka et al 30 did the DSC measurement with a heating rate of 10°C/min and observed a weak transition at 277.6°C in the first heating of the powder sample besides the two peaks at 267.7°C and 296.8°C reported by Asanuma.…”

Section: Thermal Analysis By Dscmentioning

confidence: 99%

The double melting behavior of a liquid crystalline polyimide derived from PMDA and 1,3-bis[4-(4′-aminophenoxyl) cumyl] benzene

Liu¹,

Chung²,

Oikawa³

et al. 2000

J. Polym. Sci. B Polym. Phys.

Self Cite

View full text Add to dashboard Cite

“…Polyimide (PI) containing mesogenic units on its backbone1 or polymer with in situ self‐reinforced side‐chain mosogenic units was designed to prepare high‐tensile‐strength, high‐modulus, and high‐dimensional‐stability film materials 2–5. In our previous work, novel liquid‐crystalline side‐chain in situ self‐reinforced PI film materials were achieved from PIs with pendent hydroxyl groups and monofunctional epoxide liquid‐crystal compound with conversion from pendent hydroxyl groups to functional side chains 6.…”

Section: Introductionmentioning

confidence: 99%

Novel side‐chain liquid‐crystalline polyimide for film materials

Fan

Xie

2003

J. Polym. Sci. A Polym. Chem.

View full text Add to dashboard Cite

A novel side-chain liquid-crystalline polyimide (SLCPI) was prepared via copolycondensation from 3,5-diamino-benzonic-4Ј-biphenyl ester, 4,4Ј-diamino-biphenyl ether, and 3,3Ј,4,4Ј-oxydiphthalic dianhydride. The energy-minimized structure and liquid crystallinity of SLCPI were investigated by molecular modeling, differential scanning calorimetry (DSC), wide-angle X-ray scattering, and polarized optical microscopy, respectively. The results indicated that this polyimide (PI) with side-chain mesogenic units exhibited a nematic NI phase. Because of the in situ self-reinforcement of side-chain mesogenic units, the improved tensile strength and modulus of PI films reached 270% and 300%, respectively. The coefficient of thermal expansion of films decreased by 40%. DSC and thermogravimetric analyses indicated that the phasetransition temperature of SLCPI was above 240°C, and the 5% weight-loss temperature was above 520°C. Moreover, copolycondensation of two diamines with dianhydride and incorporation of pendent mesogenic units diminished the regularity and symmetry of main chains; as a result, SLCPI exhibits good film processability.

show abstract

Aromatic thermotropic liquid crystalline polymers from 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene

Cited by 11 publications

References 2 publications

Thermal Imidization of the Precursor of a Liquid Crystalline Polyimide

Thermal Imidization of the Precursor of a Liquid Crystalline Polyimide

The double melting behavior of a liquid crystalline polyimide derived from PMDA and 1,3-bis[4-(4′-aminophenoxyl) cumyl] benzene

Novel side‐chain liquid‐crystalline polyimide for film materials

Contact Info

Product

Resources

About