摘要:
An ethylene-based polymer, e.g., LDPE, with a low dissipation factor is made by a process comprising the step of contacting at polymerization conditions ethylene and, optionally, one or more comonomers, e.g., an alpha-olefin, with at least one carbon-carbon (C—C) hydrocarbyl, free-radical initiator of Structure 1: wherein R1, R2, R3, R4, R5 and R6, are each, independently, hydrogen or a hydrocarbyl group and wherein, optionally, two or more R groups (R1, R2, R3, R4, R5 and R6) form a ring structure, with the provisos that at least one of R2 and R5, and at least one of R3 and R6 is a hydrocarbyl group of at least two carbon atoms, e.g., an alkaryl of at least seven carbon atoms.
摘要:
A process to form an ethylene-based polymer comprises polymerizing a reaction mixture comprising ethylene, at least one symmetrical polyene and at least one chain transfer agent system comprising at least one chain transfer agent (CTA) in the presence of at least one free-radical initiator and in a reactor configuration comprising at least two reaction zones, reaction zone 1 and reaction zone i (i≥2), wherein reaction zone i is downstream from reaction zone 1. The ratio of “the activity of the CTA system of the feed to the first reaction zone” to the “activity of the CTA system of the cumulative feed to the reaction zone i,” (Z1/Zi), is less than or equal to (0.8-0.2*log(Cs)), wherein Cs is from 0.0001 to 10.
摘要:
The invention provides a process to form an ethylene-based polymer, said process comprising polymerizing ethylene in the presence of at least one free-radical agent, and in the presence of a "metal alkyl-containing compound" selected from the group consisting of the following: i) at least one "Group II metal alkyl-containing compound," ii) at least one "Group III metal alkyl-containing compound," or iii) a combination of i) and ii). The invention also provides a composition comprising at least one ethylene-based polymer, prepared from a free-radical polymerization, and wherein the ethylene-based polymer has the following property: y > 0.28567x - 0.00032, wherein y = vinyl/1000C, as determined by 1H NMR, and x = mol% polymerized ?-olefin, as determined by 13C NMR. The invention also provides a composition comprising at least one ethylene-based polymer, prepared from a free-radical polymerization, and wherein the ethylene-based polymer has the following properties: A) a vinyl content greater than, or equal to, 0.3 vinyl per 1000 C (total carbons), and B) a polymerized alpha-olefin level less than, or equal to, 1.00 mole percent, based on the total moles of polymerized monomers.
摘要翻译:本发明提供一种形成乙烯基聚合物的方法,所述方法包括在至少一种自由基试剂存在下使乙烯聚合,并且在“含金属烷基化合物”存在下,选自 以下:i)至少一种“II族金属烷基化合物”,ii)至少一种“III族金属烷基化合物”,或iii)i)和ii)的组合。 本发明还提供一种组合物,其包含由自由基聚合制备的至少一种基于乙烯的聚合物,并且其中所述乙烯类聚合物具有以下性质:y> 0.28567x-0.00032,其中y =乙烯基/ 1000℃,为 通过1 H NMR测定,x = mol%聚合的α-烯烃,通过13 C NMR测定。
摘要:
A process for polymerizing ethylene to produce an ethylene -based polymer including contacting ethylene with a Ziegler-Natta procatalyst, an alkylaluminum cocatalyst and a self limiting agent selected from the group of aliphatic, cycloaliphatic, substituted cycloaliphatic or aromatic esters, anhydrides and amides such that the self limiting agent reduces polymerization rates to no greater than 40% of the polymerization rate in the absence of the self limiting agent at temperatures equal to or greater than 120 °C is provided.