Investigation of the Solution Behavior of Organosoluble Aromatic Polyimides
- 1 December 1997
- journal article
- research article
- Published by Taylor & Francis in International Journal of Polymer Analysis and Characterization
- Vol. 4 (2), 153-172
- https://doi.org/10.1080/10236669708033943
Abstract
Two high-molecular-weight organosoluble aromatic polyimides having the same diamine, 2,2′-(trifluoromethyl)-4,4′-diaminobiphenyl diamine (PFMB), but different dianhydrides, 2,2′-bis(trifluoromethyl)-4,4′,5,5′-biphenyltetracarboxylic dianhydride (HFBPDA) and 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), were prepared via one-step polycondensation reactions. Molecular weight fractionation of these two polymers was carried out and the polyimide fractions possess successively lower weight-average molecular weights. Intrinsic viscosity data from both sets of polyimide fractions gave the Mark-Houwink-Sakurada constants of these two polyimides, which reflect differing chain rigidity in tetrahydrofuran (THF) solutions. The MHS relations are [η] = 5.24 × 10−4 M0.65 and [η] = 3.77 × 10−5 M0.97 for 6FDA-PFMB and HFBPDA-PFMB, respectively. The physical meanings of these constants are discussed using the intrinsic viscosity data of these two polyimides in varying solvents. The persistence lengths are calculated based on the viscosity and molecular weight results using Bohdanecky' s approach and they were calculated to be 6.6 and 2.0 nm for HFBPDA-PFMB and 6FDA-PFMB, respectively. The experimental results indicate that the fully aromatic HFPBDA-PFMB is more rigid in THF solutions compared with 6FDA-PFMB. However, both of these polyimides are far from possessing true rigid-rod character. Plots of the weight-average molecular weight against the elution volume depict the differences in chain stiffness, and hence in hydrodynamic volume, between samples. Examination of the hydrodynamic volume of these polymers provides evidence that they both subscribe rather well to hydrodynamic theory at high molecular weights but that the stiffer HFBPDA-PFMB shows deviation at lower values.Keywords
This publication has 28 references indexed in Scilit:
- Molecular weight characterization of soluble high performance polyimides. 2. Validity of universal SEC calibration and absolute molecular weight calculationJournal of Polymer Science Part B: Polymer Physics, 1995
- Molecular weight characterization of soluble high performance polyimides. 1. Polymer‐solvent‐stationary phase interactions in size exclusion chromatographyJournal of Polymer Science Part B: Polymer Physics, 1995
- A high-temperature aromatic polyimide film displaying non-linear optical second-harmonic generation based on the approach of the poled guest–host systemJournal of Materials Chemistry, 1995
- Molecular Weight-Dependent Behavior of the Twist Distortion in a Nematic Monodomain Containing a Main-Chain Liquid Crystal PolymerMacromolecules, 1994
- Chain Conformations Of Aromatic Polvimides And Their Ordering In Thin Films.MRS Proceedings, 1991
- Organo-Soluble, Segmented Rigid-Rod Polyimides: Synthesis and PropertiesMRS Proceedings, 1991
- Dilute solution properties of semiflexible poly(substituted methylenes): intrinsic viscosity of poly(diisopropyl fumarate) in benzeneMacromolecules, 1990
- Characterization of a thermally imidized soluble polyimide filmJournal of Polymer Science Part A: Polymer Chemistry, 1990
- High performance size exclusion chromatography of polyamic acidJournal of Polymer Science Part A: Polymer Chemistry, 1988
- Polyimide solution propertiesJournal of Polymer Science Part A-2: Polymer Physics, 1969