This invention relates to treating coupled lithium initiated polymer to improve haze and stability of the resulting polymer.
Recently, polymer has been produced wherein lithium initiated polymer chains are contacted with a coupling agent to join two or more polymer molecules together. If the coupling agent contains three or more reactive sites, a radial polymer is formed with the separate polymer chains radiating out from the coupling agent nucleus. Production of such polymers is described in Zelinski et al. U.S. Pat. No. 3,281,383. A common problem in the production of such polymers, particularly resinous polymers, is the formation of an undesirable haze and a tendency of the polymer to exhibit drop off in melt flow during processing.
It is known to treat such polymers with carbon dioxide and water in order to improve stability and optical properties. This is disclosed in Hogan et al. U.S. Pat. No. 3,801,520.