Polyimides end-capped

Fig. 21.9. 67.9 MHz CP/MAS NMR spectra of P(3HB-co-37%-3HP). Most of the unassigned small signals are spinning sidebands and some others may arise from the rotor with polyimide end caps (2-ms contact time, 5-s pulse repetition time, 500 FID accumulations). B and P indicate that the signals arise from the 3HB and 3HP units, respectively. (Reproduced from J. Mol. Struct. 441 (1998) 119 with permission.)...

NASA-Langley provided a further improvement in processibility by replacing the methylenedianiline with a commercial aromatic diamine mixture that afforded even better handling characteristics (17). This type of product is formed by the reaction of formaldehyde with aniline as a precursor in isocyanate manufacture. Fluorine-containing thermoplastic polyimides and polyimides end capped with acetylene groups for cross-linking are also available as potential commercial high-temperature resins. 

STUDY ON THE SYNTHESIS AND PROPERTIES OF A NEW POLYIMIDE END-CAPPED WITH MALEIC ANHYDRIDE I.Synthesis of Amic Acid and Its Kinetics of Imidization... 

Typical Procedure for the Preparation of Polyimides End-Capped with N-Acylated Caprolactam Moieties. After a mixture of o-tolidine (OTOL) (2.1231 g, 10.000 mmol), BPDA (0.9120 g, 3.100 mmol), 2,2 -bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydryde (6FT)A) (3.2870 g, 7.400 mmol) and NMP (35.83 g, 15 wt% solid) was stirred at 22 under N2 for 10 h, 4-aminobenzoylcaprolactam (0.2322 g, 1.000 mmol) was added, and the reaction mixture was stirred for another 10 h. Pyridine (1.7600 g) and acetic anhydride (2.2440 g) were added, and the reaction mixture was stirr for an additional 24 h. The solution was diluted with NMP and poured into ethanol. The end-capped polyimide (OTOL/BPDA/6FDA, 100/30/70 molar ratio, Mn= 12,000) that precipitated was collected by filtration, washed with methanol and dried at room temperature under reduced pressure. 

Zhao L, Yao H, Liu Y, Zhang Y, Jiang Z (2013) Synthesis and properties of novel hyperbranched polyimides end-capped with metallophthalocyanines. J Appl Polym Sci 128 3405-3410... 

---

See also in sourсe #XX -- [ , , , , , , ]

---