abstract |
A process is disclosed for modifying polyethylene terephthalate so that the polyethylene terephthalate may be processed into plastic containers using conventional extrusion blow molding equipment. The polyethylene terephthalate is modified by the incorporation into a polyethylene terephthalate prepolymer of a chain branching agent and a chain terminating agent. The prepolymer is subsequently solid-state polymerized to form a polyethylene terephthalate polymer having high zero shear rate melt viscosity and shear sensitivity. This modified polyethylene terephthalate polymer may be extrusion blow molded in intermittent and continuous processes. |