- New method for synthesis of aromatic diimide dicarboxylic acid diallyl esters
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New method is suggested for synthesis aromatic diimide dicarboxylic acid diallyl esters from the corresponding acids under the action of allyl halides in aprotic polar solvents in the presence of anhydrous K2CO 3.
- Tagiev
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experimental part
p. 412 - 415
(2011/08/04)
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- Photoreactive copoly(amide-imide)s derived from 1,4-phenylenediacrylic acid and various bis(trimellitimide)s and diisocyanates
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Three bis(trimellitimide)s were prepared by condensation of the corresponding aromatic diamines with trimellitic anhydride.Two series of structurally new photoreactive copoly(amide-imide)s were synthesized by the direct polycondensation of these bis(trimellitimide)s and 1,4-phenylenediacrylic acid as comonomer with 4,4′-diphenylmethanediisocyanate (series 1) and 1,6-diisocyanatohexane (series 2), respectively. The polycondensation reaction was carried out in N-methyl-2-pyrrolidone in the presence of tripropylamine as catalyst. All of the copoly(amide-imide)s soluble in polar aprotic solvents afforded transparent, flexible and tough films. Upon irradiation in solution the p-phenylenediacryloyl unit undergoes trans-cis photoisomerization and (2 + 2)photocycloaddition. Polymers of series 1 (all fully aromatic amides) undergo also a photo-Fries rearrangement. On the contrary, the photo-Fries reaction is completely suppressed for polymers of series 2 (containing an aliphatic amide moiety).The same situation is observed in the case of polymer films. The wholly aromatic copoly(amide-imide)s show no discernible transition before decomposition, whereas the aliphatic-aromatic copoly(amide-imide)s show well-defined melting points (Tm) in the first DSC heating traces.
- Onciu, Marioara,Chiriac, Constantin I.,Vlad, Stelian,Stoica, Gheorghe,Grigoriu, George,Timpu, Daniel
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p. 641 - 648
(2007/10/03)
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- AROMATIC POLYESTERS CONTAINING HETEROCYCLIC UNITS
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New aromatic polyesters have been synthesized by solution polycondensation of dihydroxyphenylquinoxalines with diacid chlorides containing preformed imide cycles. The thermal stability of these compounds is discussed and compared with related phenylquinox
- Sava, Ion,Hamciuc, E.,Hamciuc, C.,Bruma, Maria,Simonescu, Cristofor I.,et al.
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p. 1145 - 1152
(2007/10/03)
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