Silicon-containing oligomeric poly(amides) with phthalimidyl-amide side groups: synthesis, characterization and thermal studies

Abstract

Oligomeric poly(amide)s (PAs) were synthesized from monomeric diacids, which were obtained from phthalic anhydride and the amino acid glycine, L-alanine, L-phenylalanine, L-valine, L-leucine, L-isoleucine and p-aminobenzoic acid. The phthalimidyl acids (IA-1 to IA-7) reacted with 5-amino-isophthalic acid in order to obtain the monomeric diacids (1-7). Furthermore, the monomeric diacid 8 was obtained by direct reaction between phthalic anhydride and 5-aminoisophthalic acid. The isophthalic acid derivatives were reacted with bis(4-aminophenyl)diphenylsilane in order to obtain the PAs. Monomers and polymers were characterized by infrared and 1 H-, 13 C-and 29 Si-NMR spectroscopy, elemental analysis and, when necessary, optical rotation. The results were in agreement with the proposed structures. The yields were generally good, but the inh values were low, indicating that the polymers were of oligomeric nature, namely, a chain of moderate molecular weight. The polymers were soluble in polar aprotic solvents and some of them were soluble in mcresol and tetrahydrofuran. The glass transition temperatures (T g ) values were obtained by differential scanning calorimetry, showing, in general, a decrease in value when the volume of the side chain of the amino acid moiety was increased. The thermal stability of the polymers was determined by dynamic thermogravimetry, showing good values of thermal decomposition temperatures (TDT), especially for those with aromatic residue in the amino acid, and for PA without amino acid. For PAs in which the side chain of the amino acid was larger, the TDT values were lower, probably due to the lack of symmetry and the length of the side chain, both of which have influence on the thermal stability.

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.…”

The Thermal Properties and Degradability of Chiral Polyester-Imides Based on Several l/d-Amino Acids

“…This is because the volume of the benzene ring on the side chain of PEI3d is much larger than that of the carbon chain on other polymers. The huge benzene ring leads to a larger distance between the PEIs, resulting in a smaller intermolecular force, which is called “distance effect” [ 34 , 35 , 36 ]. Therefore, the Tg value of PEI3d is the lowest.…”

Silicon-containing poly(esters) with halogenated bulky side groups. Synthesis, characterization and thermal studies

“…28,34 The thermal degradation temperatures (TDT) of the PEs were determined, for which was considered the temperature at which the polymer lost 10% of weight. When the volume of the side group is increased, the T g values decreases, due probably to a less symmetry and higher chain exibility.…”

“…The carboxylic imide-acids: phthalimidyl-acetic acid (H-I-a), 28 tetrachlorophthalimidyl-acetic acid (Cl-I-a), 29 tertrabromophthalimidyl-acetic acid (Br-I-a), 30 2-phthalimidyl-propanonic acid (H-I-b), 31 2-tetrachlorophthalimidyl-propanoic acid (Cl-I-b), 29,32 2tetrabromophthalimidyl-propanoic acid (Br-I-b), 30,32 2-phthalimidyl-3-methyl-pentanoic acid (H-I-c), 33 2-tetrachlorophthalimidyl-3-methyl-pentanoic acid (Cl-I-c), 29,32 and 2tetrabromophthalimidyl-3-methyl-pentanoic acid (Br-I-c), 30,32 were obtained from the respective phthalic-or tetrahalophthalic-anhydrides and the corresponding amino acid, according to a general procedure, in which the phthalic-or tetrahalophthalic-anhydride (0.05 mol) (phthalic anhydride 7.4 g, tetrachlorophthalic anhydride 14.3 g or tetrabromophthalic anhydride 23.2 g) was mixed with the amino acid (0.05 mol) (glycine 3.8 g, L-alanine 4.5 g, or L-leucine 6.5 g) in 50 mL of acetic acid and stirred during four hours. Then the mixture was reuxed by four hours and the acetic acid removed under vacuum.…”