Gas transport properties of homo-and copolyimides prepared from 3,3,4,4-and 2,2,3,3-thiaphthalic dianhydride ( p-TDPA and m-TDPA, respectively) with 4,4-oxydianiline (ODA) were investigated. The fractional free volume of m-TDPA-ODA is larger than that of p-TDPA-ODA, and the chain segmental mobility
Properties of copolyimides prepared from different tetracarboxylic dianhydrides and diamines
β Scribed by Hiroshi Inoue; Yoshikazu Sasaki; Toshio Ogawa
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 488 KB
- Volume
- 62
- Category
- Article
- ISSN
- 0021-8995
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β¦ Synopsis
Various copolyimides were prepared from two acid dianhydrides (BPDA, 3,3',4,4'-biphenyl tetracarboxylic dianhydride; PMDA, pyromelitic dianhydride) and two diamines (PPD, p - phenylene diamine; ODA, 4,4'-oxydianiline). The thermal and mechanical properties of these polyimides were examined in detail. By appropriately selecting the ratios of the acid dianhydride component and the diamine component, polyimide films having desirable mechanical and thermal characteristics can be obtained. Further, it was proved that there is a correlation between the properties and the compositions of the copolyimides and that the properties could be estimated from the compositions by the use of multiple regression analysis.
π SIMILAR VOLUMES
## Abstract 6FDAβMDAβbased polyimides were synthesized from a oneβstep polycondensation of 6FDA and MDA with other diamines and dianhydrides. The polyimides were characterized by GPC, FTβIR and NMR, and dense membranes were prepared from their solutions for gas separation and pervaporation. Gas sep
Four series of aromatic polyimides (PIs V-VIII) composed of biphenyltetracarboxylic dianhydrides (BPDAs) and aromatic diamines bearing alkylene spacers were prepared by two methods. Most polymers could be readily prepared in a one-step method for the combination of a-BPDA with β£,-bis(3-aminophenoxy)
Tg's were obtained by differential scanning calorimetry (DSC) (Rigakudenki thermal analyzer 8055D1) and Td's by TG-DTA (Rigakudenki 8075D1). IR spectra were recorded on a Hitachi 270-30 spectrophotometer.