Processes for correlating UV-VIS spectra of norbornene compound to polymerization processes using the same, and related purification methods and compositions

A method of increasing a catalyst's efficiency in a polymerization of a mixture comprising ethylene, at least one α-olefin and 5-ethylidene-2-norbornene, said method comprising polymerizing the ethylene and the at least one α-olefin in the presence of the 5-ethylidene-2-norbornene, which comprises low levels of impurities, as determined by the absorbances at the following wavelengths:

• 320 nm and 343 nm, in a neat sample of the 5-ethylidene-2-norbornene, contained in a quartz sample holder with a one centimeter pathlength, and
• wherein 5-ethylidene-2-norbornene is monitored by UV absorbance, and wherein the 5-ethylidene-2-norbornene having a sum of absorbances, at 320 nm and 343 nm, less than, or equal to, 0.31, is selected for polymerization.

A method of purifying 9-ethylidene-2-norbornene, said method comprising thermally treating said 5-ethylidene-2-norbornene, optionally under reduced pressure, to form a purified 5-ethylidene-2-norbornene, which comprises low levels of impurities, as determined by the absorbances at the following wavelengths:

• 320 nm and 343 nm, in a neat sample of the 5-ethylidene-2-norbornene, contained in a quartz sample holder with a one centimeter pathlength, and
• wherein the sum of the absorbances at 320 nm and 343 nm is less than, or equal to, 0.31.

A method of purifying 5-ethylidene-2-norbornene, said method comprising passing the 5-ethylidene-2-norbornene through a column, to form a purified 5-ethylidene-2-norbornene, which comprises low levels of impurities, as determined by the absorbances at the following wavelengths:

• 320 nm and 343 nm, in a neat sample of the 5-ethylidene-2-norbornene, contained in a quartz sample holder with a one centimeter path length, and wherein the sum of the absorbances at 320 nm and 343 nm is less than, or equal to, 0.31.

A method of purifying 5-ethylidene-2-norbornene, said method comprising chemically treating the 5-ethylidene-2-norbornene, to form a purified 5-ethylidene-2-norbornene, which comprises low levels of impurities, as determined by the absorbances at the following wavelengths:

• 320 nm and 343 nm, in a neat sample of the 5-ethylidene-2-norbornene, contained in a quartz sample holder with a one centimeter pathlength, and wherein the sum of the absorbances at 320 nm and 343 nm is less than, or equal to, 0.31.