Hot Topics

Vol. 60, No. 12, December (2011)

Advanced Reverse Osmosis Membrane with Fine Pore Structure
Masahiro HENMI
Global Environment Research Laboratories, Toray Industries, Inc.

RO membrane technologies have made great progress in the seawater and brackish water desalination field. Advanced membranes are still demanded to achieve lower cost, lower energy consumption and higher water quality. In order to obtain future excellent performance, Toray has been executing fundamental research on RO membranes by investigating physical and chemical properties through PALS (Positron annihilation lifetime spectroscopy) study, Molecular Dynamics Simulation and TEM (Transmission electron microscopy) analysis, which has resulted in advanced RO membranes with high flux, high rejection, excellent chemical durability and so on. Figure 1 shows SEM and 3D-TEM images of such a RO membrane surface. Quantitative data such as membrane thickness and surface area have been obtained. The data are effective for developing RO membranes with fine pore structure.
Polymer Preprints, Japan 2011, 60, 28.

Automated Enzymatic Glycan Synthesis using Aminooxy-Functionalized PAMAM Dendrimer
Faculty of Advanced Life Science, Hokkaido University
We have developed an automated enzymatic synthesis of oligosaccharides based on a polymer-supported approach. In our automated method, polymer separation is a crucial step because the polymers, which are lost cumulatively by repetitive separations, directly influence the outcome of the automated synthesis. Recently, we found that the rates of poly(amidoamine) (PAMAM) dendrimers (generation 6 (58 kDa) and 7 (116 kDa)) are much better than polyacrylamide in a test using a hollow fiber ultrafiltration module (10 kDa MWCO). Our finding encouraged us to utilize the PAMAM dendrimers as alternatives to polyacrylamide-based polymer support conventionally used in our method. Our latest automated protocol afforded the Sialyl Lewis X tetra-saccharide derivative in 16% overall yield for 4 days from a simple N-acetyl-D-glucosamine linked to an aminooxy- functionalized G7 dendrimer.
J. Am. Chem. Soc. 2010, 132, 16651.

Synthesis and Properties of Novel Asymmetric Addition-type Imide Resins Based on Kapton-type Structures for Carbon Fiber Reinforced Composite with High Heat Resistance
Masahiko MIYAUCHI*, Kenichi KAZAMA, Yuichi ISHIDA, Toshio OGASAWARA, and Rikio YOKOTA
Frontier Material Development Laboratories, Kaneka Corporation
Novel phenylethynyl (PEPA) terminated addition-type imide oligomers (repeated unit n=4) derived from pyromellitic dianhydride (PMDA), 2-phenyl-(4,4'-diaminodiphenyl ether)(p-ODA), and 9,9-bis(aminophenyl)fluorene (BAFL) with asymmetric and non-planar structures showed a high solubility and very low minimum melt viscosity. These imide oligomers were also successfully converted to cross-linked cured resins with Kapton-type backbone structures after molding at 370 degreeC/1 MPa. for 1 hour. The glass transition temperature and elongation-at-break of the cured resins were found to be almost 360 degreeC and >10%, respectively. These epoch-making imide oligomers also showed excellent processability for molding carbon fiber reinforced composites (CFRP) with high heat resistance via imide-wet pre-preg.
Polymer Preprints, Japan 2010, 59, 3622.