Preparation of Polyethylene Glycol Monomethyl Ether Chitosan-diethylenetriamine Pentaacetic Acid and Its Effect on 89SrCl2 Excretion and Radiation Protection in the Digestive Tract of Rats

In this study, hydrophilic polymer polyethylene glycol monomethyl ether chitosan-diethylenetriamine pentaacetic acid (mPEGCS-DTPA) was synthesized via chemical synthesis and cross-linking, and its cytotoxicity and radiation protective effect in vivo were studied. The results revealed that mPEGCS-DTPA exhibits good cytocompatibility and increases the excretion of radionuclides through the digestiveand urinary tracts. The pathological results of the small intestine revealed that mPEGCS-DTPA exerts a good radiation-protective effect and could reduce the α and β-emitting radiation-induced damage of the intestinal mucosa. MPEGCS-DTPA can increase the excretion of radionuclides in the digestive tract and exhibits effective protection against radiation.

Pressure Swing-Based Reactive Distillation and Dividing Wall Column for Improving Manufacture of Propylene Glycol Monomethyl Ether Acetate

Propylene glycol monomethyl ether acetate (PGMEA) is a commonly used solvent in the rapidly developing semiconductor industry. Ultra-high purity PGMEA is required for this ultra-precision industry and to satisfy the current strict waste management regulations. The traditional PGMEA production process consumes considerable energy and has a high production cost. In this study, a novel heat integrated and intensified design, which applies a dividing wall column, reactive distillation, and pressure swing techniques, was proposed for improving the energy efficiency and reducing the cost of PGMEA production. Heat integration was applied to maximize the heat recovery of the process. All processes were simulated using the commercial simulator Aspen Plus V11. The economic and environmental parameters of the process alternative were assessed for a fair comparison with the conventional process. The results showed that heat integration of the optimal pressure swing-based reactive distillation and dividing wall column processes could reduce the energy requirement and TAC by 29.5%, and 20.8%, respectively, compared to that of the optimal conventional process. The improved design provides a strong basis for achieving more sustainable PGMEA production.