Polyetherimide Polymer Research Articles

Roles of Molecular Architecture and End-Group Functionality on the Surface Properties of Branched Polymers

The effects of molecular architecture on the surface properties of polyetherimide polymer films were investigated. For polymers ranging in structure from hyperbranched to completely linear, it was ...

The influence of casting solution structure on the microporosity of polyetherimide gas separation membranes prepared by the coagulation post-leaching method

The microporosity and performance of polyetherimide (PEI) membranes produced by the coagulation post-leaching technique were investigated. Computational chemistry and chemical structure principles indicate that a lithium cation solvated in NMP ( N-methyl-2-pyrrolidinone) forms a complex with two NMP molecules. This complex was determined to be stable in NMP and isopropanol but not in methanol or water. Increasing the additive (LiNO 3) concentration in the casting solution lead to a greater number of micropores in the 0.7–1.2 nm range, while the peak in the micropore distribution remained unchanged at 1.0 nm. Molecular mechanics calculations indicate that the PEI polymer chain can form coils having an inner section of 0.7 nm×1.0 nm. Micropore measurements and computational chemistry results suggest that the inherent size of the PEI polymer coils remains unchanged on the addition of LiNO 3 but the number of polymer coils increases. A linear relation was found to exist between the permeance of the membranes to air and micropore volume. Larger micropores were present at higher LiNO 3 concentrations and caused a decline in the actual separation factor for these membranes.

Synthesis and properties of fluoro‐polyetherimides

AbstractA series of amorphous fluoro‐polyetherimides based on 2,2′‐bis(3,4‐dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and di‐ether‐containing diamines 4,4′‐bis(3‐aminophenoxy)diphenyl sulfone (m‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl sulfone (p‐SED), 4,4′‐bis(4‐aminophenoxy)diphenyl propane (BPADE) were synthesized. These melt processable polyetherimide polymers fromp‐SED and BPADE showed excellent electrical properties. The dielectric constants, 2.74 and 2.65 at 10 MHz respectively, are lower than commercially available polyetherimide ULTEM® 1000, and polyimide Kapton® H films. In addition, we found that trifluoromethyl groups‐containing polyimides not only show extraordinary electrical properties, but they also exhibit excellent long‐term thermo‐oxidative stability and reduced water absorption relative to non‐fluorinated polyimides. The weight retention of these fluoro‐polyetherimides at 315°C for 300 h in air varies from 93% to 98%. Whereas, their moisture absorption at 100 RH at 50°C was in the range of 0.3% to 1.05%, which is much lower than those of Ultem 1000 and Kapton H. In the case of fluoro‐polyetherimides fromp‐SED andm‐SED (paraandmetaisomers) diamines with ‘ether’ and sulfonyl (‐SO2‐) spacer groups, thed‐spacing andTgvalues decreased from 4.72Å to 4.56Å and 293°C to 244°C respectively. Similarly, the transparency of these polymer films (in the range of 80% to 90%) at 500 nm solar wavelength was higher than Ultem 1000 and Kapton H.

Polyetherimide (Ultem®) Spin Cast Films by XPS

A spin cast film of polyetherimide (Ultem® 1000, GE Plastics) was analyzed by XPS using monochromatic Al Kα excitation. The measured atomic composition closely matched the expected stoichiometry of the polymer. Peak positions of the individual chemically shifted C 1s, O 1s, and N 1s components are reported. The results are in general agreement with other reported spectra of polyetherimide polymers: experimental, C 83.0%, O 12.9%, and N 4.1%; theoretical, C 82.2%, O 13.3%, and N 4.3%.