Preparation of New Optically Active and Thermally Stable Poly(amide-Imide) Containing Bicyclo Segment and Ether Group in the Main Chain by Direct Polycondensation in Two Different Media

Abstract

A new series of optically active and thermally stable poly(amide-imide)s (PAIs) with good inherent viscosities based on bicyclo diacids and etheric diamine in the main chain were synthesized from the direct polycondensation reaction of N, N΄-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-l-amino acids 3a-g with 1,2-Bis[4-aminophenoxy]ethane 7 by direct polycondensatios with two different media such as direct polycondensation in a medium consisting of n-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride (CaCl 2 )/pyridine (Py) and direct polycondensation in a tosyl chloride (TsCl)/pyridine (Py)/n,ndimethylformamide (DMF) system. Also 3a-g were synthesized by the condensation reaction of bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride 1 with two equimolars of various amino acids such as l-alanine 2a, l-valine 2b, l-leucine 2c, l-isoleucine 2d, l-phenylalanine 2e, l-2-aminobutyric acid 2f and l-histidine 2g in an acetic acid solution.The polymerization reactions produced a series of thermally stable and optically active organosoluble PAIs. The resulting polymers were fully characterized by means of FT-IR and 1 H-NMR spectroscopy, elemental analyses, inherent viscosity, specific rotation, solubility tests and differential scanning calorimeter (DSC). Also thermal properties of the PAIs 8a-g were investigated using thermal gravimetric analysis (TGA) and derivative of thermaogravimetric (DTG) analysis.

Non-Conventional Fluorescence and Cytotoxicity of Two Aliphatic Hyperbranched Polymer Dots Having Poly(amic acid) Structures: Implications for Labeling Nanodrug Carriers

“…We recorded nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and XPS spectra to confirm the structures of our PDs. A comparison of the 1 H NMR spectra of BCDA, EDTAD, Jeffamine T-403, and the PDs revealed that only those of the PDs featured signals at 7.94 ppm, representing the H atoms of their amido groups (Figure a–e). − Figure S3a displays the FTIR spectra of BCDA and EDTAD, featuring signals for the symmetric and asymmetric stretching of their CO units in the ranges 1761–1774 and 1809–1822 cm –1 , respectively. , After the dianhydrides had reacted with the triamine to form poly­(amic acid)­s with amido and carboxyl groups, Figure S3b reveals that the FTIR spectra of PD-BT-12 and PD-ET-12 lacked any signals for symmetric and asymmetric stretching of the CO units of the dianhydride but signals had emerged for amide I and II vibrational modes in the ranges 1543–1560 and 1657–1663 cm –1 , respectively …”