Abstract: A method of controlling long chain branching in an ethylene-based polymer includes polymerizing ethylene with one or more optional monomers to form an ethylene-based polymer, and controlling a degree of long chain branching (LCB) in the ethylene-based polymer. The degree of LCB ranges from 0.1 per 1000 carbon atoms in the polymer backbone to 10 per 1000 carbon atoms in the polymer backbone, as measured by 13CNMR. The degree of LCB is controlled by adding one or more branched vinyl ester to the polymerizing step in an amount ranging from 0.01 mol % to 5.0 mol %, relative to total monomer content. A polymer composition contains the ethylene-based polymer. An article includes the polymer composition containing the ethylene-based polymer.

Abstract: The invention relates to an additive-manufacture feedstock, comprising an ethylene-vinyl ester polymer having a melt flow rate of from 0.1 to 150 g/10 min (190° C./2.16 kg), measured according to ASTM D 1238, and a vinyl ester content of from about 1.0 wt % to about 30 wt %, wherein the ethylene-vinyl ester polymer exhibits a Shore A hardness of at least about 60. The pellets and filaments produced from the additive-manufacture feedstock have a high degree of printability in material-extrusion-based 3D printing technology, and can be used to produce 3D printing articles with a high consistency to the targeted 3D model and substantially no warpage. The invention also relates to methods of making the additive-manufacture feedstock and methods of 3D printing using the additive-manufacture feedstock in various forms.

Abstract: A method of controlling long chain branching in an ethylene-based polymer includes polymerizing ethylene with one or more optional monomers to form an ethylene-based polymer, and controlling a degree of long chain branching (LCB) in the ethylene-based polymer. The degree of LCB ranges from 0.1 per 1000 carbon atoms in the polymer backbone to 10 per 1000 carbon atoms in the polymer backbone, as measured by 13CNMR. The degree of LCB is controlled by adding one or more branched vinyl ester to the polymerizing step in an amount ranging from 0.01 mol % to 5.0 mol %, relative to total monomer content. A polymer composition contains the ethylene-based polymer. An article includes the polymer composition containing the ethylene-based polymer.

Abstract: A method may include polymerizing ethylene in a tubular reactor, where the polymerization is substantially free of a chain transfer agent. A method may include polymerizing ethylene in a tubular reactor, the ethylene having a specific delivery pressure and the polymerization having one or more specific peak temperatures. The molecular weight of the resulting polyethylene may be controlled by the selection of the delivery pressure and the one or more peak temperatures.

Abstract: A method may include polymerizing ethylene in a tubular reactor, where the polymerization is substantially free of a chain transfer agent. A method may include polymerizing ethylene in a tubular reactor, the ethylene having a specific delivery pressure and the polymerization having one or more specific peak temperatures. The molecular weight of the resulting polyethylene may be controlled by the selection of the delivery pressure and the one or more peak temperatures.