Novel flame retardant poly(thiourea-sulfone-imide)s for high temperature applications: synthesis and characterization

Abstract

Abstract:The synthesis and polymerization of a novel diamine monomer, 1,1-(sulfonylbis (4,1-phenylene)) bis (thiourea) (SPT), with various aromatic dianhydrides were carried out. In addition, the fabrication of poly(thiourea-sulfone-imide)s (PTSIs) with noble thermal properties and flame retardancy was conducted. The structures of SPT and polymers were characterized by FT-IR, 1 H NMR, and 13 C NMR spectroscopy along with elemental analysis. Crystallinity, organosolubility, inherent viscosity, and gel permeation chromatographic measurements were taken as well. The amorphous nature was exhibited by PTSIs containing C = S and -SO 2 -moieties in the backbone that were readily soluble in highly polar organic solvents. The inherent viscosities of PTSIs were 0.89-1.13 dL g −1 and molecular weights were 87,000-96,550 g mol −1 , respectively. Their thermal stability was studied in terms of temperature at 10% weight loss, which ranged between 478 and 526• C under inert atmosphere. Polyimides had a glass transition temperature around 253-268 • C depending on the dianhydrides used. The flame retardant properties of PTSIs were studied in terms of limiting oxygen index values and were measured in the range of 50-56.

Synthesis and Characterization of New Organosoluble and Thermally Stable Polyimides Containing Pyridine and Anthracene Units

“…The order of moisture absorption was found to be BTDA‐PI > ODPA‐PI > HFDA‐PI. HFDA based polyimides show lowest moisture absorption since fluorine introduces hydrophobic nature which inhibits the absorption of water molecules on the surface of polymers …”

“…HFDA based polyimides show lowest moisture absorption since fluorine introduces hydrophobic nature which inhibits the absorption of water molecules on the surface of polymers. [40,41] Conclusion A series of new polyimides were synthesized from pyridine-bridged aromatic diamines, including 4-(9-anthryl)-2,6-bis(4aminophenyl) pyridine, 4-(9-anthryl)-2,6bis[4-(4 0 -aminophenoxy)phenyl]pyridine, 4-(9-anthryl)-2,6-bis[4-(4 0 -aminobenzoyloxy)phenyl]pyridine and various aromatic dianhydrides. All the monomers and polymers were fully characterized by FT-IR, 1 H-NMR techniques.…”

Bis‐thiourea Derivatives and Their Utility in Synthesis of Mono‐heterocyclic, Bis‐heterocyclic, and Fused Heterocyclic Systems

“…Treatment of bis(4‐aminophenyl)sulfone 45 with concentrated hydrochloric acid and ammonium thiocyanate upon steam bath heating yielded the bis‐thiourea 46 in 86% (Scheme ) .…”

First Row Transition Metal Complexes Derived from N, Nʹ-Substituted Thiourea: Synthesis, Geometrical Structures and Cyclic Voltammetry Probe: A Review

“…The variation in electronegativity between oxygen and sulfur atoms make the properties of thiourea different than urea in spite of the similarity of their structure [1]. Thiourea by itself has some applications such as starting material to prepare thiourea dioxide which is used as reducing agent in textile treatment, producing flame delaying resins [2][3][4] vulcanization expediter [5] and copy papers for example diazo papers. Thioureas compounds are involving under its banner, big series of substances with public formula (R 1 R 2 N)(C=S)(R 3 R 4 N), R in general indicates to alkyl or aryl group (See Figure 1).…”