Water as Solvent in Polyimide Synthesis: Thermoset and Thermoplastic Examples

Abstract

A combination of increasingly stringent environmental legislation and economic competition is driving industrial processes further and further towards the three “E”s of chemical manufacture: economy, efficiency and environmental impact. In this paper, we present a novel aqueous method for the synthesis of polyimides. The products resulting from this process perform similarly, through both qualitative and quantitative comparisons, to those conventionally produced using high boiling dipolar aprotic solvent. This highly efficient one-pot method potentially provides economic advantage through low solvent cost and environmental impact benefit from the manageable aqueous waste.

Structuring and characterization of a novel highly microporous PEI/BMI semi-interpenetrating polymer network

“…Therefore, these spectra were deleted, as they did not provide any additional information. Comparing the FTIR spectrum of PEI-EtOH membrane with commercial Ultem 1000 [24], the same peaks were observed particularly in the fingerprint region (900-1300 cm K1 ) as defined elsewhere [25]. As shown in Fig.…”

“…The increase in these two peaks might be attributed to NH stretching in amide group [4] (Table 4) resulting from hydrolysis and cleavage of imide groups, which have a higher concentration in BMI than PEI ( Table 3). The remaining peaks were similar to the commercial PEI (Ultem 1000) film and had two major weak peaks at 2967.35 and 3067.21 cm K1 in addition to a very weak peak at 3521.9 cm K1 as described elsewhere [24].…”

Association between bone mineral density and C‐reactive protein in a large population‐based sample

“…The chemical structures of the bare Mg and PEI‐coated Mg specimens with the porous and dense layers were characterized by FTIR, as shown in Figure 3(A–C). Both of the PEI‐coated Mg specimens showed the typical characteristic bands of the PEI polymer29 [Fig. 3(B,C)].…”

Microwave‐Assisted Aqueous Polyimidization Using High‐Throughput Techniques

“…In similar previous studies, we have used a Parr pressure reactor for this process. [5,9] Using the Biotage 1 reactor and high-throughput characterization techniques, this entire process was completed in a few weeks by one person. Table 1 contains the data obtained for the first optimization phase using 4,4 0 -ODA with 6-FDA.…”

“…[4] The use of water under pressure as solvent for the synthesis of a wide variety of polyimides from amine-carboxylic acid salts has been studied by our group for a number of years and has shown to have significant advantages for many of the commercially important polyimide types due to the reduced solvent costs and minimized environmental problems of the method. [5][6][7][8][9][10] The utility of water-based synthesis has recently been further highlighted with the promotion of an ''on water'' synthetic protocol in small molecule synthesis. [11] The aqueous polyimide synthetic method has another notable feature in that it is a one-step method and does not proceed via an isolable polyamic acid intermediate.…”