A polymer composition comprising: at least one polymer ingredient selected from the group consisting of a polymer (A) having a side chain (a) containing a hydrogen-bonding cross-linking moiety with a carbonyl-containing group and/or a nitrogen-containing heterocycle and having a glass transition point of 25 C. or lower, and a polymer (B) containing a hydrogen-bonding cross-linking moiety and a covalent-bonding cross-linking moiety in a side chain and having a glass transition point of 25 C. or lower, wherein both the polymer (A) and the polymer (B) are a reaction product of a specific copolymer (X) with a cross-linking agent.

Multi-reactor systems for the production of low-density polyethylene (LDPE) polymers and copolymers, wherein a first reactor product stream has a total mass flow of from about 10% to about 80% of the total mass flow of the second reactor product stream, methods of using the same, and processes of monitoring the same.

A process for polymerizing ethylene in a high-pressure polymerization system having a continuously operated polymerization reactor and a reactor blow down system having an emergency valve, a reactor blow down vessel containing an aqueous medium and a reactor blow down dump vessel, wherein the process includes the steps of monitoring the polymerization system for a disturbance, opening the emergency valve when a disturbance occurs to allow the content of the polymerization system to expand into the reactor blow down vessel, contacting the content of the polymerization system in the reactor blow down vessel with the aqueous medium to obtain an aqueous polymer slurry, separating the polymer slurry and gaseous components, and transferring the polymer slurry to the reactor blow down dump vessel.

The invention relates to a polyethylene having a melt flow rate at (2.16) kg loading (MFR.sub.2), determined according to method ISO1133-1:2011, which MFR.sub.2 is A g/10 min and A.sub.1≤A≤A.sub.2; wherein A.sub.1 is (0.5) and A.sub.2 is (1.70), and containing a total amount of vinyl groups which is B vinyl groups per (1000) carbon atoms, and B.sub.1≤B, wherein B.sub.1 is (0.45), determined according to method ASTM D6248-98, a polymer composition, an article being e.g. a cable, e.g. a power cable, and processes for producing a polyethylene, a polymer composition and an article, and an article; useful in different end applications, such as wire and cable (W&C) applications.

The invention relates to a polyethylene having a melt flow rate at (2.16) kg loading (MFR.sub.2), determined according to method ISO1133-1:2011, which MFR.sub.2 is A g/10 min and A.sub.1≤A≤A.sub.2; wherein A.sub.1 is (0.5) and A.sub.2 is (1.70), and containing a total amount of vinyl groups which is B vinyl groups per (1000) carbon atoms, and B.sub.1≤B, wherein B.sub.1 is (0.45), determined according to method ASTM D6248-98, a polymer composition, an article being e.g. a cable, e.g. a power cable, and processes for producing a polyethylene, a polymer composition and an article, and an article; useful in different end applications, such as wire and cable (W&C) applications.

Methods for producing polyethylene compositions having broader melt index ratio and narrower molecular weight distribution in high pressure multi-feed tubular reactors are provided. The methods are useful in multi-feed tubular reactors comprising three or more reaction zones. The first reaction zone or the first and second reaction zone having a peak temperature that is lower than standard peak temperatures for polymerization of ethylene monomer in a tubular reactor.

A method for predicting physical properties of a polyethylene resin is provided, which can reliably predict a proper charging ratio of a crosslinking agent in the production process of a low density crosslinked polyethylene resin, and the physical properties of the polyethylene resin achieved therefrom. A method for producing a polyethylene resin by applying the same method is also provided.

Provided are an ethylene-vinyl acetate copolymer having a high degree of crosslinking by controlling a temperature difference in an autoclave reactor and an input ratio of an initiator during polymerization, even though a reduced amount of a crosslinking agent is used, and a preparation method thereof.

This disclosure relates to systems and processes for cooling polymer product mixtures manufactured at high pressure. The processes of the invention involve cooling and then subsequently reducing the pressure of the product mixture from the reactor. In the systems of the invention, a product cooler is located downstream of the high pressure reactor and upstream of a high pressure let down valve.

This disclosure relates to systems and processes for cooling polymer product mixtures manufactured at high pressure. The processes of the invention involve cooling and then subsequently reducing the pressure of the product mixture from the reactor. In the systems of the invention, a product cooler is located downstream of the high pressure reactor and upstream of a high pressure let down valve.