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New Y‐shaped (AB2‐type) amphiphilic copolymers of poly(ethylene glycol) (PEG) with poly(trimethylene carbonate) (PTMC), PEG‐b‐(PTMC)2, were successfully synthesized by the ring‐opening polymerization (ROP) of TMC with bishydroxy‐modified monomethoxy‐PEG (mPEG). First, a bishydroxy functional ROP initiator was synthesized by esterification of acryloyl bromide with mPEG, followed by Michael addition using excess diethanolamine. A series of Y‐shaped amphiphilic PEG‐(PTMC)2 block copolymers were obtained via ROP of TMC using this PEG with bishydroxyl end groups as macroinitiator and ZnEt2 as catalyst. The amphiphilic block copolymers with different compositions were characterized by gel permeation chromatography (GPC) and 1H NMR, and their molecular weight was measured by GPC. The results showed that the molecular weight of Y‐shaped copolymers increased with the increase of the molar ratio of TMC to mPEG‐(OH)2 initiator in feed while the PEG chain length was kept constant. The Y‐shaped copolymer mPEG‐(PTMC)2 could self‐assemble into micelles in aqueous medium and the critical micelle concentration values of the micelles decrease with increase in hydrophobic PTMC block length of mPEG‐(PTMC)2. The in vitro cytotoxicity and controlled drug release properties of the Y‐shaped amphiphilic block copolymers were also investigated. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 8131–8140, 2008

BACKGROUND: Walnut shell, a nutshell waste, was used to prepare activated carbons (AC) for desulfurization. Titanium ore (TO), TiO 2 or Fe 2 O 3 was blended into the resulting carbonized powders, which were extruded into cylinders and activated under CO 2 atmosphere. The desulfurization activity of samples was evaluated in a fixed bed under a simulated gaseous mixture from coal combustion.

Fe supported on activated carbons treated by HNO 3 (Fe/NAC) was prepared using the incipient wetness method with ultrasonic-assisted oscillation and calcined at different temperatures. The physical and chemical properties were studied using FTIR, XPS, XRD and H 2 -TPR, and SO 2 removal ability of Fe/NAC was also evaluated at a fixed bed. The results showed that α-Fe 2 O 3 and small Fe 3 O 4 coexist in Fe/NAC-500, while catalysts calcined at 700°C only possess Fe 3 O 4 . Fe 3 O 4 with small Fe 2 SiO 4 is observed for Fe/NAC-900, but Fe 2 SiO 4 and Fe 0 are detected in Fe/NAC-1000, indicating that the interactions between Fe precursor and activated carbons are very complex, and C atoms may take part in the reduction of iron oxides. The relative content of C−C and C−O decreases first and then increases when calcination temperatures increase from 500 to 1000°C, but that of CO and OCOH has a contrary trend, suggesting that calcination temperatures influence the formation of functional groups. Fe/NAC-900 shows the best activity and has a sulfur capacity of 322 mg/g, which is related closely to O COH and good crystallinity of Fe 3 O 4 . Fe 3 O 4 is the main active phase in the SO 2 removal process. After desulfurization, O COH, α-Fe 2 O 3 , Fe 3 O 4 , and Fe 0 disappear, and Fe 2 (SO 4 ) 3 is observed, leading to the decrease of SO 2 removal ability.