LIGAND EFFECT OF CATALYTIC SYSTEM WCl_6-Et_2Al FOR RING OPENING METATHESIS POLYMERIZATION OF DICYCLOPENTADIENE

Ligand effect of the catalytic system WCl6-Et2AlCl for ring opening metathesis polymerization (ROMP) of dicyclopentadiene (DCPD) was investigated. The experimental results show that adding sterically hindered phenol-2. 6-di-tert-butylcresylol(DTBC) in the catalytic system not only can obviously increase the monomer conversion of polymerization but also improve the mechanical properties, such as notched impact strength (NIS), tensile strength (TS) ect. 5 of the synthesized polyicycolpentadiene (PDCPD). A similar effect can be observed by using a sterically hindered polymeric phenol - linear phenol formaldehyde resin (LPF) as a ligand.

Polymerization of Dicyclopentadiene by Reaction Injection Molding

Dicyclopentadiene was polymerized by reaction injection molding (RIM) using a catalyst system based on molybdenum (V) chloride and anhydrous aluminum chloride and triethylaluminum. The effect of the reaction temperature on the polymer network and the type of the polymerization were discussed.

Diels-Alder Addition of Dicyclopentadiene with Cyclopentadiene in Polar Solvents

Diels-Alder addition of dicyclopentadiene and cyclopentadiene in polar solvents has been studied to produce tricyclopentadiene（TCPD） that is a potential high-density fuel precursor. GC and MS analysis shows that the adducts contain two isomers, namely exo- and endo-TCPD. Theoretical simulation shows that although the transition state of endo-TCPD has a lower activation energy, exo-TCPD is thermodynamically preferred. Polar solvents can accelerate the reaction rate and improve the exo/endo ratio of TCPD because the transition state of exo-TCPD has a higher polarity than that of endo-TCPD. The solvent effect follows the order of polarity： benzyl methanol〉cyclohexanone〉toluene. The conversion rises when the temperature ranges from 120 to 150 ℃, but the selectivity of TCPD slightly decreases. Increasing the pressure can improve the conversion but the exo/endo ratio of TCPD is unchanged. The apparent kinetics in different solvents was determined via nonlinear regression. The activation energies are 99.47, 101.15, and 107.32 kJ/mol for benzyl methanol, cyclohexanone, and toluene, respectively. The optimal reaction conditions are as follows： benzyl methanol as solvent, temperature 150 ℃, and pressure 900 kPa. After an 11-hour reaction, a conversion of 58.0%, a TCPD selectivity of 95.7%, and an exo/endo ratio of 1/5.3 has been obtained.

Synthesis and Curing Properties of a Novel Novolac Curing Agent Containing Naphthyl and Dicyclopentadiene Moieties

A novel novolac curing agent containing both naphthalene and dicyclopentadiene (DCPD) moieties was prepared to produce a highly heat-resistant cured polymer network. The chemical structure was characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, mass spectrometry, and gel permeation chro-matography analyses. The thermal properties of the resulting polymer from diglycidyl ether of bisphenol A epoxy resin cured with the novel curing agent were evaluated using dynamic mechanical thermal analysis and thermogra-vimetric analysis. Compared with the conventional curing agent, the resulting polymer cured with naphtha-lene/DCPD navolac shows considerable improvement in heat resistant properties such as higher glass transition temperature (Tg) and thermal stability. The result also shows better moisture resistance because of the hydrophobic nature of naphthalene/DCPD structure.

Highly efficient Rh(Ⅰ)/tris-H_8-binaphthyl monophosphite catalysts for hydroformylation of dicyclopentadiene to dialdehydes

Novel catalytic systems for the Rh‐catalyzed hydroformylation of dicyclopentadiene have been developed using tris‐H8‐binaphthyl monophosphite as ligands containing different ester substituents at the 2’‐binaphthyl position(OCOMe,OCOPh,OCOAdamantyl and OCOPhCl).The catalysts exhibited high activity(S/C=4000,TON=3286)with good to excellent selectivity towards dialdehydes.Remarkably,the Rh(I)complex bearing the ligands with chlorophenyl ester substituents led to 99.9%conversion and 98.7%selectivity for dialdehydes under relatively mild conditions(6 MPa,120°C).

Copolymerization of Ethylene with Dicyclopentadiene Using a Constrained Geometry Cyclopentadienyl-phenoxytitanium Catalyst

The copolymerization of ethylene with dieyclopentadiene （DCP） in the presence of a constrained geometry tetramethylcyclopentadi-enyl-phenoxytitanium catalyst [ 2,4-＇ Bu2-6-（ 2,3,4,5-Me4 -Cp ） -PhO ] TICl2, combined with AI（ iBu）3/Ph3C^＋ B（ CsF5 ）4^- cocatalyst system was studied. The copolymers that were formed were characterized by ＇ H and ,3 C NMR, differential scanning calorimetry （ DSC）, SEM, and X-ray diffraction （XRD） analyses. The re- suits of the analysis indicate that the copolymers of ethylene with dicyclopentadiene are amorphous and display two or more melting temperatures in their DSC diagrams. Moreover, the morphologies of the copolymers are quite different from that of polyethylenes.

Preparation and Characterisation of Cyclopentadienyl Tetramethylethene－bridged Dicyclopentadienylsamarium（Ⅲ）Tetrahydrofuranate Complexes

The complexes of cyclopentadienyl tetramethylethenebridsied dicyclopentadienylsamarium (Ⅲ) tetrahydrofuranates, Me4C2(C5H4)2LnC5H5 (THF) (Ln = Nd, Sm, Gd, Yb) were synthesized and characterized by elemental analysis, IR, 1HNMR, thermogravimetry and MS. The crystal structure of Me4C2(C5H4)2SmC5H5 was determined by X-ray diffraction method. The crystal belongs orthorhombic space group Cc2a. with a =1 . 1696(6) nm, b =1 .2539(5) nm, c = 2.9432(15) nm, V= 4.316 (4) nm3, Z= 8 and Dc = 1 . 54 g . cm-3.