Synthesis and characterization of novel poly(amide-imide…

N2 - A series of high molecular weight hyperbranched poly(ether imide)s (HBPEI), derived from the AB2 monomer N-[3,5-di(tert-butyldimethylsilyloxy)phenyl]-4-fluorophthalimide (1), were synthesized in a single-step process involving a rapid fluoride-catalyzed arylation reaction. NMR analysis of the degree of branching shows that changes in the polymerization reaction time, from 2.5 to 20.0 min, result in hyperbranched polymers with degrees of branching ranging from 66% to 42%, respectively. Reactions of selected model compounds show that changes in the degree of branching are a result of molecular rearrangements occurring via a transetherification mechanism. Such rearrangements lead to an increase in Mw while Mn remains relatively constant. Correlations between rheological data and the degree of branching of the hyperbranched poly(ether imide)s were observed. For solutions of the hyperbranched poly(ether imide)s, rheological measurements showed that shear thinning and normal stress effects increased as the degree of branching decreased and that birefringence as a function of shear rate increased with decreasing degree of branching. While strong correlations between the degree of branching and rheological properties exist, light scattering GPC measurements show that Mw increases significantly with reaction time. This variation in Mw suggests that the differences in rheological properties may be largely due to changes in molecular weight and makes it difficult to determine the role that changes in the degree of branching, which are manifested in altered molecular architecture, have on macroscopic physical properties.

Synthesis and photocatalytic activity of poly(triazine imide).

The nitrogen in imides is not very basic, which allows it to form stable compounds with halogens. Treatment of imides with halogens and base gives the N-halo derivatives. Examples that are useful in organic synthesis are -chlorosuccinimide and -bromosuccinimide, which respectively serve as sources of "Cl+" and "Br+" in organic synthesis.


Synthesis of imide | cockgememoslogecanlinktunselfbrid

Synthesis and Photocatalytic Activity of Poly(triazine imide)

A series of high molecular weight hyperbranched poly(ether imide)s (HBPEI), derived from the AB2 monomer N-[3,5-di(tert-butyldimethylsilyloxy)phenyl]-4-fluorophthalimide (1), were synthesized in a single-step process involving a rapid fluoride-catalyzed arylation reaction. NMR analysis of the degree of branching shows that changes in the polymerization reaction time, from 2.5 to 20.0 min, result in hyperbranched polymers with degrees of branching ranging from 66% to 42%, respectively. Reactions of selected model compounds show that changes in the degree of branching are a result of molecular rearrangements occurring via a transetherification mechanism. Such rearrangements lead to an increase in Mw while Mn remains relatively constant. Correlations between rheological data and the degree of branching of the hyperbranched poly(ether imide)s were observed. For solutions of the hyperbranched poly(ether imide)s, rheological measurements showed that shear thinning and normal stress effects increased as the degree of branching decreased and that birefringence as a function of shear rate increased with decreasing degree of branching. While strong correlations between the degree of branching and rheological properties exist, light scattering GPC measurements show that Mw increases significantly with reaction time. This variation in Mw suggests that the differences in rheological properties may be largely due to changes in molecular weight and makes it difficult to determine the role that changes in the degree of branching, which are manifested in altered molecular architecture, have on macroscopic physical properties.