Synthesis, Characterization and Thermal Studies of Wholly Aromatic Poly(imide-Amides) Containing Si and/or Ge in the Main Chain

Abstract

Poly(imide-amides) (PIAs) containing the heteroatoms Si and/or Ge in the main chain were obtained from diacids, which were synthesized from trimellitic anhydride and the diamines bis(4-aminophenyl)diphenylsilane or bis(4-aminophenyl)diphenylgermane. With the same diamines the polymers containing the heteroatoms Si and Ge in the main chain were obtained. Polymers were soluble in aprotic polar solvents and characterized by IR and 1 H, 13C and 29Si NMR spectroscopy, and the results were in agreement with the proposed structures. Low inherent viscosity values (h inh ) (0.04 -0.12 dL/g) were obtained, indicating the presence of oligomeric species. The Tg values were obtained by differential scanning calorimetry (DSC), and the results did not show a relation with the nature of the heteroatoms, in the sense that the polymers with Si should have higher Tg values than those with Ge due to the lower volume of the former atom. Also, the low values of h inh associated to low molecular weight species, have important influence on Tg values. The thermal decomposition temperatures were obtained by dynamic thermogravimetry. These analyses showed that the highest thermal decomposition temperature (TDT) values were obtained for PIA-II and PIA-III with Si and Ge in the repeating unit, and the lowest TDT values with two Si atoms in the unit.

Synthesis and characterization of aromatic poly(ether-imide)s based on bis(4-(3,4-dicarboxyphenoxy)phenyl)-R,R-silane anhydrides (R = Me, Ph) – spontaneous formation of surface micropores from THF solutions

“…[11][12][13] On the other hand, silicon-containing polymers have been extensively developed for variable applications due to their characteristic high solubility, high thermal and oxidative stability, ame and moisture resistance and good adhesion onto semiconductor substrates. [14][15][16][17][18][19] Bruma et al 20 have described that the introduction of a silarylene group [-PhSi(R 1 R 2 )Ph-] in the main chain leads to improved solubility without loss of thermal properties. These properties can be explained by the lower electronegativity of the silicon atom than that of carbon, causing a small dipole moment inside the chain, which increases its polarity and therefore, its solubility in specic polar solvents.…”

Poly(amide-imide-esters) derived from asymmetric diacids and diphenols containing silicon or carbon as central atom. Synthesis, characterization and thermal studies

“…[22] In our research group, we have described the synthesis and characterization of condensation polymers containing several functional groups and Si atoms in the main chain, showing that the incorporation of this heteroatom increases the solubility and maintains the thermal stability of the materials. [12,[23][24][25][26][27] In this work we describe the synthesis, characterization, and thermal studies of condensation polymers containing three organic functional groups in the repeating unit (amide, imide, and ester) and a Si atom provided by the diphenol moiety. The diacids are asymmetric in the sense that one acid group is of aliphatic nature provided by the amino acid, except when p-aminobenzoic acid was used, and the other is aromatic.…”

Silarylene-containing oligo(ether-amide)s based on bis(4-(4-amino phenoxy)phenyl)dimethylsilane. Effect of the dicarboxylic acid structure on some properties

“…From these works, several polymerizations have been developed with diamines containing diphenylsilane unit (Ph-Si-Ph), where the silicon atom is bonded to combinations of R 1 ¼ methyl and R 2 ¼ phenyl 8 as well as R 1 ¼ R 2 ¼ methyl 6,9 or phenyl. 6,[9][10][11][12][13][14][15][16][17][18][19][20] On the other hand, the inclusion of ether linkages into the chain of PAs has been explored by several research groups. Thus, diverse difunctional monomers have been synthesized and the properties of the derived polymers were established, with special attention to the solubility and their thermal parameters.…”