Patent ID: 6297330
Filing Date: 2001-10-02
Classification: C08G

Abstract:
A process for polymerizing cyclic oligomers, wherein cyclic oligomers are polymerized as homopolymers or co-polymers, said process conducted in the presence of one or more linear polymers, conducted with a recycle loop for recycling linear polymer to the process, wherein the linear polymer is recycled to an oligomer feed by means of the recycle loop, and optionally conducted in the presence of a polymerization catalyst, wherein the cyclic oligomer is selected from the group consisting of cyclic forms of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthenate, polyethylene isophthalate, sulfonated cyclic oligoester and sulfonated polyethylene isophthalate, and wherein the linear polymer is selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthenate, and any co-polymer thereof.