Synthesis and characterization of aromatic polyamides containing alkylphthalimido pendent groups

Abstract

A series of polyisophthalamides containing pendent phthalimido groups and flexible side spacers were prepared from four novel diacids and three commercial aromatic diamines. These polyamides were prepared in high yields and with high molecular weights by direct polycondensation with triphenyl phosphite and pyridine as condensing agents. The weight‐average and number‐average molecular weights, measured by gel permeation chromatography, were 70,000–137,000 and 47,000–86,000 g/mol, respectively. The novel polyamides were amorphous and readily soluble and showed glass‐transition temperatures of 150–240 °C, as measured by differential scanning calorimetry. Thermogravimetric analysis showed that the 10% weight‐loss temperatures in nitrogen were 355–430 °C, a significant improvement in thermal stability having been observed with the increase in the side‐chain length. A theoretical quantum mechanical study was successfully carried out to explain these results. Flexible and tough films, cast from polymer solutions, showed tensile strengths of 50–125 MPa. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3711–3724, 2002

Synthesis of Oligomeric Silicon-containing Poly(imide-amide)s Derived from Trimellitic Anhydride and Amino-Acids. Vibration Spectral, Optical, Thermal and Morphological Characterization

“…These modifications are also associated with the diminishing of the molecular interactions, which can lead to lower Tg values but maintaining the thermal properties (2)(3)(4)(5)(6)(7)(8).…”

Direct polyamidation in green media: Studies on thermal degradation of novel organosoluble and optically active flame retardant polyamides

“…Therefore, numerous efforts have been made to improve their processability by structural modification. The incorporation of pendent bulky, packing-disruptive groups along the polymer backbone outcomes in a less ordered polymer matrix, hence increasing the solubility characteristics, while other advantageous properties are retained [22][23][24].…”

A study of the ionic liquid mediated microwave heating for the synthesis of new thermally stable and optically active aromatic polyamides under green procedure

“…Bulky side groups also give rise to restricted segmental mobility, so that the overall observable effect is a remaining high T g and an enhancement in solubility at the same time. [31][32][33][34][35][36][37][38] In previous study we reported the synthesis and characterization of optically active PAs containing phthalimide and L-alanine amino acid linkages using conventional condensing agents such as NMP, Pyridine (Py), triphenyl phosphite (TPP) and CaCl 2 under microwave conditions. 39 The present work deals with the synthesis of novel organosoluble, thermally stable optically active PAs containing pendant L-leucinephthalimide and benzamide groups via direct polyamidation under green conditions using microwave heating in conjunction with a green solvent, imidazolium-based ILs and TPP as a modern and safe methodology.…”