POLYPROPYLENE WITH FREE-END LONG CHAIN BRANCHING, PROCESS FOR MAKING IT, AND USE THEREOF

摘要

0077K 2001-2POLYPROPYLENE WITH FREE-END LONG CHAINBRANCHING, PROCESS FOR MAKING IT, AND USE THEREOFAbstract of DisclosuresDisclosed is normally solid, gel-free, amorphous topredominantly crystalline, polypropylene characterized bystrain hardening believed to be due to molecular chains thathave substantial, free-end long branches of propylene units.Also disclosed is a process for making it by high energyradiation of linear polypropylene in a reduced active oxygenenvironment, maintaining the irradiated material in suchenvironment for a specific period of time, and then deacti-vating free radicals in the material.Further disclosed is the use of the strain hardeningpolypropylene in extensional flow operations such as, forexample, extrusion coating, film production, andthermoforming.