A method for evaluating long-term durability of a resin for piping is provided. Unlike the conventional FNCT evaluation method requiring a long period of time, the method disclosed herein is capable of predicting long-term durability of a resin for piping in a short time, by a simple calculation using a content of tie molecules, an entanglement molecular weight (M.sub.e) and a content of ultrahigh molecular weight components. In addition, the olefinic polymer is configured to have a predetermined relationship in relation to the content of tie molecules, the entanglement molecular weight (M.sub.e) and the content of ultrahigh molecular weight components, whereby the polymer of the present application can be used in the manufacture of a heating pipe requiring excellent long-term durability.

Blown films, especially monolayer blown films, with an improved property profile, the blown films comprising at least 95.0 wt% of a specific heterophasic propylene copolymer (TERHECO).

Blown films, especially monolayer blown films, with an improved property profile, the blown films comprising at least 95.0 wt% of a specific heterophasic propylene copolymer (TERHECO).

A multimodal polyethylene composition having a lower molecular weight (LMW) ethylene homo or copolymer component (A) and a higher molecular weight ethylene copolymer component (B); wherein the lower molecular weight component comprises: (ai) a first fraction which comprises an ethylene homo or copolymer of ethylene and one or more C3-10 alpha olefins; and (aii) a N second fraction which comprises a different ethylene homo or copolymer of ethylene and one or more C3-10 alpha olefins; wherein the multimodal polymer composition has a density of 930 kg/m.sup.3 or more (ISO1183), such as 938 to 955 kg/m.sup.3, an MFR2 (ISO1133 at 190° C. and 2.16 kg load) in the range of 0.05 to 10 g/10 min, and a flexural modulus of up to 800 MPa, such as 300 to 800 MPa (ISO 178:2010).

A multimodal polyethylene composition having a lower molecular weight (LMW) ethylene homo or copolymer component (A) and a higher molecular weight ethylene copolymer component (B); wherein the lower molecular weight component comprises: (ai) a first fraction which comprises an ethylene homo or copolymer of ethylene and one or more C3-10 alpha olefins; and (aii) a N second fraction which comprises a different ethylene homo or copolymer of ethylene and one or more C3-10 alpha olefins; wherein the multimodal polymer composition has a density of 930 kg/m.sup.3 or more (ISO1183), such as 938 to 955 kg/m.sup.3, an MFR2 (ISO1133 at 190° C. and 2.16 kg load) in the range of 0.05 to 10 g/10 min, and a flexural modulus of up to 800 MPa, such as 300 to 800 MPa (ISO 178:2010).

It is provided a process for producing an ethylene copolymer comprising compressing ethylene monomer at a certain pressure; adding a fresh comonomer in liquid form and, optionally, a fresh modifier in liquid form at a certain pressure to the compressed ethylene monomer; introducing the resulting compressed mixture into an autoclave reactor having a first reaction zone and at least one more reaction zone, the first reaction zone having a volume that is greater than 50% of the total reactor volume, and, optionally, at least one additional reactor; adding at least one free radical initiator in order to start a polymerization reaction; and separating the ethylene copolymer from the reaction mixture; wherein all the compressed ethylene monomer or the compressed mixture are introduced into the first reaction zone of the autoclave reactor, and wherein the compressed mixture is introduced into the autoclave reactor and, optionally, into the at least one additional reactor at a temperature from −20° C. to 70° C.

It is provided a process for producing an ethylene copolymer comprising compressing ethylene monomer at a certain pressure; adding a fresh comonomer in liquid form and, optionally, a fresh modifier in liquid form at a certain pressure to the compressed ethylene monomer; introducing the resulting compressed mixture into an autoclave reactor having a first reaction zone and at least one more reaction zone, the first reaction zone having a volume that is greater than 50% of the total reactor volume, and, optionally, at least one additional reactor; adding at least one free radical initiator in order to start a polymerization reaction; and separating the ethylene copolymer from the reaction mixture; wherein all the compressed ethylene monomer or the compressed mixture are introduced into the first reaction zone of the autoclave reactor, and wherein the compressed mixture is introduced into the autoclave reactor and, optionally, into the at least one additional reactor at a temperature from −20° C. to 70° C.

Embodiments of polyethylene formulations and articles comprising polyethylene formulations are disclosed. The polyethylene formulation may include from 45 wt. % to 90 wt. % of an MDPE having a density of from 0.930 g/cc to 0.950 g/cc and a melt index (I.sub.2) from 0.05 g/10 min to 0.5 g/10 min; from 10 wt. % to 50 wt. % of a polyethylene composition having a density from 0.910 g/cc to 0.936 g/cc and a melt index (I.sub.2) from 0.7 g/10 min to 1.0 g/10 min; and from 0.5 wt. % to 5% of a masterbatch composition. The polyethylene composition may comprise a first polyethylene fraction area in a temperature range of 45° C. to 87° C. of an elution profile via improved comonomer composition distribution (iCCD) analysis method and a second polyethylene fraction area in a temperature range of 95° C. to 120° C. of an elution profile via iCCD.

Embodiments of polyethylene formulations and articles comprising polyethylene formulations are disclosed. The polyethylene formulation may include from 45 wt. % to 90 wt. % of an MDPE having a density of from 0.930 g/cc to 0.950 g/cc and a melt index (I.sub.2) from 0.05 g/10 min to 0.5 g/10 min; from 10 wt. % to 50 wt. % of a polyethylene composition having a density from 0.910 g/cc to 0.936 g/cc and a melt index (I.sub.2) from 0.7 g/10 min to 1.0 g/10 min; and from 0.5 wt. % to 5% of a masterbatch composition. The polyethylene composition may comprise a first polyethylene fraction area in a temperature range of 45° C. to 87° C. of an elution profile via improved comonomer composition distribution (iCCD) analysis method and a second polyethylene fraction area in a temperature range of 95° C. to 120° C. of an elution profile via iCCD.

Described herein are modified thermoplastic polyurethanes, methods of reactively extruding the modified thermoplastic polyurethanes, and methods of using the modified thermoplastic polyurethanes. The modified thermoplastic polyurethanes are mi-cro-crosslinked through reaction with a functional polyolefin, have significantly improved tensile strength and elongation compared to unmodified thermoplastic polyurethanes, and may be extruded.