Effects of polymerization conditions when making norbornene‐ethylene copolymers using the metallocene catalyst ethylene bis (indenyl) zirconium dichloride and MAO to obtain high glass transition temperatures

Abstract

Using 70 mol % norbornene in the monomer mixture before polymerization, the influences of different polymerization conditions were studied. It was found that by increasing the temperature from 10 to 70ЊC, the yield increased and the molecular weight decreased; and when increasing the ethylene pressure from 2 to 6 atm, yield and molecular weight increased. The highest glass transition temperatures, however, were achieved at 30ЊC and 4 atm. Further improvements could be obtained by increasing the amount of catalyst or Al/Zr ratio. Using the conditions of 30ЊC, 4 atm, 4 mg catalyst, 3000 Al/Zr, 250 mL toluene solution, and 30 min, the amount of norbornene was increased from 31.1 to 90 g, resulting in an increase in the glass transition temperature from 98 to 155ЊC.

Chemical structure and physical properties of cyclic olefin copolymers (IUPAC Technical Report)

“…Recently, Bergström et al [18,19] reported the results of molecular weight and polydispersity index of ethene-norbornene copolymers determined by GPC in 1,2,4-trichlorobenzene. They observed the GPC peak area decreased with increasing norbornene content and the signal disappeared at a norbornene mole fraction close to 29 %.…”

Copolymerization of ethylene with 5-vinyl-2-norbornene in the presence of the Ph2C(Flu)(Cp)ZrCl2 /MAO catalyst

“…[1][2][3][4][5][6] However, the remarkable drawback of group 4 metallocene catalysts is their limited ability to polymerize polar monomers. This deactivation of the catalyst is due to the coordination of heteroatoms of functional groups of the comonomer molecule to the Lewis acidic metal center.…”

Solid‐state NMR study of cyclo‐olefin copolymer (COC)

“…[3][4][5][6][7][8][9][10] The polymerization temperature was controlled at 66°C with a catalyst/cocatalyst ratio ranging from 3000 to 7000, and the ethylene pressure was maintained at 19 -21 psi. The total volume of the system was 60 -65 mL during the 2 h of polymerization time.…”