Studies on novel semi‐2‐IPNs from polyetherimide and citraconimide

Abstract

A series of novel semi-2-interpenetrating polymeric networks (semi-2-IPNs) were prepared through blending in solution using two different polyimides, biscitraconamic acid as a precursor of biscitraconimide (MBMI) with various proportions of polyetherimide (PEI) to achieve optimum properties. Biscitraconamic acid was prepared by reacting citraconic anhydride (CA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) and bis(3aminopropyl)phenyl phosphine (BAPPP) and it was characterized by differential scanning calorimetry (DSC), FTIR, and 1 H-NMR spectroscopy. Both biscitraconamic acid and PEI were blended in N,N-dimethylacetamide (DMAc) solution, casted and thermally cured up to 300 C to give semi-2-IPNs. The MBMI/PEI semi-IPN systems were characterized by UV-Vis spectroscopy, FTIR spectroscopy and ther-mal techniques. The phase morphology, isothermal aging, and water uptake of semi-IPN systems have also been studied. The morphological studies on phase distribution were investigated by scanning electron microscopy (SEM). Thermal performance of MBMI/PEI semi-IPN systems were evaluated by DSC and thermo gravimetric analysis (TGA). All the compositions of semi-IPN polyimide system were stable up to 400 C and their thermal stability increased with increase in the content of PEI. Isothermal aging studies done at 300 C for various time periods showed good thermo-oxidative stability.

Thermogravimetric study of thermal degradation of polyetherimide

“…PEI brings outstanding elevated thermo oxidative stability, high strength and stiffness, broad chemical resistance, exceptionally low smoke generation, and inherent flame retardancy. It is one of the candidate materials for energy storage.…”