Embodiments of the invention described herein relate to a polyethylene polymer composition suitable for use in the manufacture of packaging articles, flexible films and/or sheets. In one embodiment, the copolymer comprises a polyethylene resin with density 0.918 g/cm.sup.3 to about 0.935 g/cm.sup.3, G′ at G″.sub.(500 Pa) value, as determined from Dynamic Mechanical Analysis at 190° C., of less than 40 Pa, M.sub.z/M.sub.w of greater than 2, CDBI.sub.50 of greater than 60. Other embodiments relate to polymer compositions with defined molecular characteristics and formulations suitable for use in the manufacture of articles including films, sheets, bags and pouches with improved creep resistance and high toughness and a good balance of film stiffness and processability in monolayer and/or multi-layer film structures.

Embodiments of the invention described herein relate to a polyethylene polymer composition suitable for use in the manufacture of packaging articles, flexible films and/or sheets. In one embodiment, the copolymer comprises a polyethylene resin with density 0.918 g/cm.sup.3 to about 0.935 g/cm.sup.3, G′ at G″.sub.(500 Pa) value, as determined from Dynamic Mechanical Analysis at 190° C., of less than 40 Pa, M.sub.z/M.sub.w of greater than 2, CDBI.sub.50 of greater than 60. Other embodiments relate to polymer compositions with defined molecular characteristics and formulations suitable for use in the manufacture of articles including films, sheets, bags and pouches with improved creep resistance and high toughness and a good balance of film stiffness and processability in monolayer and/or multi-layer film structures.

A method of preparing an acrylonitrile-based copolymer for a carbon fiber. The method includes: preparing a reaction solution including a (meth)acrylonitrile-based monomer and a first reaction solvent; adding a first portion of a radical polymerization initiator to the reaction solution to initiate polymerization; and adding a second portion of the radical polymerization initiator to the reaction solution when a polymerization conversion ratio is between 70 to 80%.

Provided herein are VLDPE polymer compositions suitable for use in the manufacture of flexible films or sheets. In one embodiment, the copolymer comprises a polyethylene VLDPE resin with M.sub.z/M.sub.w of greater than 2, CDBI.sub.50 of greater than 55 and a single melting peak in DSC measurement. The polymer compositions disclosed herein may be suitable for use in the manufacture of films with improved balance of film toughness, processability and sealability in monolayer and multi-layer film structures.

Provided herein are VLDPE polymer compositions suitable for use in the manufacture of flexible films or sheets. In one embodiment, the copolymer comprises a polyethylene VLDPE resin with M.sub.z/M.sub.w of greater than 2, CDBI.sub.50 of greater than 55 and a single melting peak in DSC measurement. The polymer compositions disclosed herein may be suitable for use in the manufacture of films with improved balance of film toughness, processability and sealability in monolayer and multi-layer film structures.

A polymer composition may include a polymer produced from ethylene, and one or more vinyl carbonyl monomers having the general structure (I): ##STR00001##
where R.sup.1, R.sup.2 and R.sup.3 are independently selected from a group consisting of hydrogen, halogen, hydroxyl, alkyl, substituted alkyl, alkoxy, substituted alkoxy, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aralkyl, (heterocyclo)alkyl, (heteroaryl)alkyl, (amino)alkyl, (alkylamino)alkyl, (dialkylamino)alkyl, carboxamino(alkyl), (cyano)alkyl, alkoxyalkyl, hydroxyalkyl, heteroalkyl, substituted cycloalkyl, substituted cycloalkoxy, substituted aryl, and substituted heterocycles; and Y and Z are independently selected from a group consisting of O, (CR.sup.5aR.sup.5b), (CHR.sup.6a)—R.sup.6b, phenylene, CH—OR.sup.7, and NR.sup.8, wherein R.sup.5a, R.sup.5b, R.sup.6a, R.sup.6b, and R.sup.8 are independently selected from a group consisting of hydrogen, halogen, CH.sub.2, and alkyl, and wherein R.sup.7 is independently selected from a group consisting of hydrogen; halogen; hydroxyl; alkyl; linear ether; cyclic ether; Si(R.sup.9).sub.3, wherein R.sup.9 is independently selected from a group consisting of hydrogen, halogen, and alkyl; and (C═O)—R.sup.10, wherein R.sup.10 is an alkyl; and R.sup.4 is independently selected from a group consisting of halogen, hydroxyl, alkyl, substituted alkyl, alkoxy, substituted alkoxy, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aralkyl, (heterocyclo)alkyl, (heteroaryl)alkyl, (amino)alkyl, (alkylamino)alkyl, (dialkylamino)alkyl, carboxamino(alkyl), (cyano)alkyl, alkoxyalkyl, hydroxyalkyl, heteroalkyl, substituted cycloalkyl, substituted cycloalkoxy, substituted aryl, and substituted heterocycles, where the polymer composition has a number average molecular weight (M.sub.n) ranging from 5 kDa to 10000 kDa obtained by GPC.

The invention provides compositions, each comprising an ethylene/alpha-olefin interpolymer, which has a reduced level of a low density, low molecular weight oligomeric fraction, as indicated by an HCC value, as described herein, and reduced levels of inorganic content or lower Tm. The invention also provides processes for forming such interpolymers.

Described herein are methods for continuous solution polymerization. The method may comprise polymerizing one or more monomers and comonomers in the presence of a solvent in a polymerization reactor to produce a polymer solution; determining the composition of the polymer solution exiting the polymerization reactor in an on-line fashion; determining at least one of the critical pressure or critical temperature; comparing the critical pressure and/or critical temperature to the actual temperature of the polymer solution and the actual pressure of the polymer solution; heating or cooling the polymer solution to a temperature within 50° C. of the critical temperature; and passing the polymer solution through a pressure letdown valve into a liquid-liquid separator, where the pressure of the polymer solution is reduced or raised to a pressure within 50 psig of the critical pressure to induce a separation of the polymer solution into two liquid phases.

Described herein are methods for continuous solution polymerization. The method may comprise polymerizing one or more monomers and comonomers in the presence of a solvent in a polymerization reactor to produce a polymer solution; determining the composition of the polymer solution exiting the polymerization reactor in an on-line fashion; determining at least one of the critical pressure or critical temperature; comparing the critical pressure and/or critical temperature to the actual temperature of the polymer solution and the actual pressure of the polymer solution; heating or cooling the polymer solution to a temperature within 50° C. of the critical temperature; and passing the polymer solution through a pressure letdown valve into a liquid-liquid separator, where the pressure of the polymer solution is reduced or raised to a pressure within 50 psig of the critical pressure to induce a separation of the polymer solution into two liquid phases.

Described herein are methods for continuous solution polymerization. The method may comprise polymerizing one or more monomers and comonomers in the presence of a solvent in a polymerization reactor to produce a polymer solution; determining the composition of the polymer solution exiting the polymerization reactor in an on-line fashion; determining at least one of the critical pressure or critical temperature; comparing the critical pressure and/or critical temperature to the actual temperature of the polymer solution and the actual pressure of the polymer solution; heating or cooling the polymer solution to a temperature within 50° C. of the critical temperature; and passing the polymer solution through a pressure letdown valve into a liquid-liquid separator, where the pressure of the polymer solution is reduced or raised to a pressure within 50 psig of the critical pressure to induce a separation of the polymer solution into two liquid phases.