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Poly(ferrocenyldimethylsilanes) with different molecular weights, especially with high molecular weight, have been synthesized. It is found by using the ESR technique that the formation of charge transfer complexes (CTC) between poly(ferrocenyldimethylsilanes) with different molecular weights and tetracyanoethylene (TCNE) is possible. Using 2,2,6,6-Tetramethyl-piperidone-1 as a spin probe, the segment motion of resultant polymers was investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3508–3511, 2002

Using BF 3 as probe, the surface of SiO 2 was probed. The effects of the roast temperature on the SiO 2 surface were investigated and a possible mechanism is suggested. Using SiO 2 as starting material for supports, new supported catalysts for copolymerization of ethylene and propylene were prepared and their possible structures are discussed. It was found that higher polymerization productivity, for instance, 480 kg P/mol Ti h, can be obtained by using a SiO 2 /Al 2 Et 3 Cl 3 /TiCl 4 catalytic system and addition of PhMgCl to this catalytic system can significantly increase polymerization activity.

Three vanadocene-cocatalyst catalytic systems for ethylene polymerization-Cp 2 ZrCl 2 /Al 2 Et 3 Cl 3 [dichlorobis(η-cyclopentadienyl)vanadium/ethylaluminumsesquichloride], Cp 2 ZrCl 2 /MAO [dichlorobis(η-cyclopentadienyl)vanadium/methylaluminoxane] and Cp 2 ZrCl 2 /AlEt 3 [dichlorobis(η-cyclopentadienyl)vanadium/triethylaluminum]-were monitored by electron spin resonance (ESR) spectroscopy. It was found that at least a certain kind of vanadium complex is formed after mixing dichlorobis(η-cyclopentadienyl)vanadium with ethylaluminumsesquichloride. After introducing ethylene, a new kind of vanadium complex is detected by ESR. Ethylene can be polymerized by using a dichlorobis(η-cyclopentadienyl)vanadium/ethylaluminumsesquichloride catalytic system. These results possibly indicate that the vanadium complex exists in the forms ClCp 2 VClEtAlCl 2 and ClCp 2 VClEtAlClEt, which are responsible for forming active centers. The Dichlorobis(η-cyclopentadienyl)vanadium/methylaluminoxane and dichlorobis(η-cyclopentadienyl)vanadium/triethylaluminum systems also were monitored by ESR. Completely different spectra were recorded compared to those of the dichlorobis(η-cyclopentadienyl) vanadium/ethylaluminumsesquichloride system. Ethylene almost cannot be polymerized by the dichlorobis(η-cyclopentadienyl)vanadium/ methylaluminoxane and dichlorobis(η-cyclopentadienyl)vanadium/triethylaluminum catalytic systems, showing that resultant vanadium complexes of dichlorobis(η-cyclopentadienyl)vanadium/methylaluminoxane and dichlorobis(η-cyclopentadienyl)vanadium/triethylaluminum catalytic systems are different from that arising from the dichlorobis(η-cyclopentadienyl)vanadium/ethylaluminumsesquichloride system. Plausible mechanisms are suggested for this.

Poly(ester urethane) (PU) with functional groups (amide, hydroxyl, carboxyl) on surfaces were prepared by grafting monomers such as acrylamide (AAm), hydroxyethyl acrylate (HEA), and methacrylic acid (MAA) onto the PU membranes. Grafting copolymerization was carried out by the combined use of photooxidization and UV irradiation grafting. The PU membrane was photooxidized in hydrogen peroxide solution under UV light to yield hydroperoxide groups on the surface and then irradiation grafting with monomer in water. The ATR-FTIR spectrum, X-ray photoelectron spectroscopy characterized the grafted copolymers and verified the occurrence of grafting copolymerization. The results showed that the content of hydroperoxide groups yielded was dependent on the photooxidization time and reached maximum at about 8 h. Grafting copolymerization was enhanced when irradiating by UV light. The degree of grafting was increased with the increase of content of hydroperoxide groups, irradiation time, and monomer concentration. The grafting copolymerization was enhanced when an appropriate amount of ferrous ions was added. After grafting, the wettability of PU and the water absorption percentage increased with the degree of grafting. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2505–2512, 2000

Nanometer magnetic particles were prepared through oxidizing Fe 2+ in basic solution. Initially, using resultant nanometer magnetic powder as support, supported nanometer magnetic Ziegler-Natta catalysts were obtained. Through polymerization in situ on the surface of nanometer magnetic particles, a new kind of magnetic polyolefin that is different from both the composite plastics' magnet and the structure plastics' magnet was obtained.

Using VO2+ as a spin probe, a new method to obtain microenvironmental information on supports was developed which can be used in the choice of supports for coordination catalysts. Utilizing the above method, NaY was chosen as second support component. A complex support catalyst VOCl3/MgCl2/NaY/Al2Et3Cl3 was prepared and used in ethylene–propylene copolymerization. Higher polymerization activity was obtained with this catalytic system. Alternating the ratio of two kinds of supports, the composition and sequence structure of copolymers could be controlled, which showed that NaY participated in the active species, affected the insertion of monomer, and changed the composition and sequence structure of copolymers. © 1994 John Wiley & Sons, Inc.