Activated Carbons Containing Dispersed Metal Oxide Particles for Removal of Methyl Mercaptan in Air

Activated carbons containing dispersed metal oxide particles were prepared by carbonization of phenol resin containing metal compounds followed by steam activation. Acetylacetonates of Fe, Mn and V, and Cu nitrate were used as the sources of metals. The removal of a small amount of methyl mercaptan (CH3SH) in air with these activated carbons was tested in a flow system. Compared with activated carbons without metal oxides, the carbons exhibited high activity for the removal of CH3SH in air. In particular, activated carbon obtained from Novolac containing 5 wt% Cu showed excellent behavior over a long time.

SUBSTITUENT EFFECTS OF tert-BUTYL GROUPS ON FLUORENYL LIGAND OF [t-BuNSiMe2Flu] ZrMe2

[t-BuNSiMe_2(2,7-t-Bu_2Flu)]ZrMe_2 and[t-BuNSiMe_2(3,6-t-Bu_2Flu)]ZrMe_2 were synthesized,and the solid structure of complex[t-BuNSiMe_2(2,7-t-Bu_2Flu)]ZrMe_2 was elucidated by single crystal X-ray analysis.These complexes were applied for propylene polymerization using dried modified methylaluminoxane as a cocatalyst at 0℃and 20℃in toluene.Both systems did not show activity at 0℃,but they conducted the polymerization at 20℃.The introduction of t-butyl substituents to the fluorenyl ligand improved the activ...

Supercritical Fluid Impregnation of Essential Bark Oil in Copolymers of L-Lactide with 7-Membered Cyclic Compounds

In order to develop a novel controlled-release material, we previously attempted to impregnate poly(L-lactide) (poly(L-LA)), poly(L-LA-ran-CL) (CL: ε-caprolactone) or poly(L-LA-ran-TEMC) (TEMC: tetramethylene carbonate) with low boiling point, organic useful compounds using supercritical carbon dioxide (scCO2) as the solvent. In this work, the factors influencing impregnation of poly (L-LA) random copolymers with useful compounds were investigated under scCO2 using the copolymers previously used. The influence of temperature, pressure, and time on the impregnation contents of the useful compounds on the copolymers was evaluated. The polymer used, which is a base of this material, was poly(L-LA-ran-CL), poly(L-LA-ran-TEMC), or poly(L-LA-ran-DXO) (DXO: 1,5-dioxepan-2-one). Statistical random copolymers of L-LA with CL, TEMC, or DXO were synthesized using Sn(oct)2 as a catalyst at 150°C for 24 h without solvent. Preparation of the controlled-release materials was carried out using essential bark oil from Thujopsis dolabrata var. hondae and synthetic L-LA random copolymers as a base material under scCO2. The impregnation experiment, which investigated the influence of pressure, was conducted in the range of 10 to 20 MPa. The influence of temperature on impregnation was carried out at 40°C to 100°C. Impregnation time was varied from 1 to 5 h. The pressure of essential oil impregnated into poly(L-LA) random copolymers was the highest at 14 MPa. In the influence of temperature on impregnation, the amount of essential oil increased with increasing temperature.

PRECISE SYNTHESIS OF OLEFIN BLOCK COPOLYMERS USING A SYNDIOSPECIFIC LIVING POLYMERIZATION SYSTEM

This feature article summarizes the synthesis of novel olefin block copolymers using fast syndiospecific living homo- and copolymerization of propylene, higher 1-alkene, and norbornene with ansa-fluorenylamidodimethyltitanium- based catalyst according to the authors＇ recent results. The catalytic synthesis of monodisperse polyolefin and olefin block copolymer was also described using this living system.

Synthesis of Granular Hydroxy‑Functionalized Ultra‑high‑molecular‑weight Polyethylene and Its Fiber Properties

Granular hydroxyl-functionalized UHMWPE was successfully prepared through copolymerization of ethylene and 10-undecen-1-ol protected by tri-iso-butylaluminum using a titanium complex.[tBuNSiMe_(2)(2,7-tBu2Flu)]TiMe_(2) was activated in hexane by silica-supported modified-methylaluminoxane.Without any additional pretreatments,the obtained polymer powders were transformed into fibers through a gel-spinning and heat drawing process.When compared to fibers generated from the equivalent unfunctionalized UHMWPE or the commercial HUMWPE,both creep resistance and hydrophilic properties were improved in the hydroxy-functionalized UHMWPE fibers without losing tensile strength.