摘要:
A method of modifying a tubular low density polyethylene (LDPE) is disclosed. In the method ethylene is polymerized with a free radical initiator in a high pressure reactor to form an LDPE. The LDPE is then reacted with a free radical initiator to produce a modified polyethylene. The modified polymer has an increased long chain branching index as indicated by the increase in the gel permeation chromatography branching index.
摘要:
A novel highly grafted, multi-functional olefin copolymer is provided comprising an additive reaction product of a method comprising reacting acylating agent with an olefin copolymer having a number average molecular weight greater than about 1,000 in the presence of a free radical initiator and essentially free of hydrocarbon solvent in an extruder to provide an olefin copolymer intermediate comprising an acylated olefin copolymer having a degree of grafting (DOG) of at least 0.5 wt. %, which copolymer intermediate's molecular weight is reduced, vacuum stripped of unreacted components, pelletized, dissolved in a neutral oil (preferably with inert gas sparging), and further reacted with a polyamine to provide a grafted multi-functional olefin copolymer viscosity modifier, and lubricating oil concentrates and compositions containing the same and uses thereof.
摘要:
A process for improving the melt characteristics of polyethylene resins is provided. The process involves contacting a polyethylene resin powder with a low level of free radical initiator at a temperature below the melting point of the resin.
摘要:
A process for producing polypropylene having increased melt strength, the process comprising (i) homopolymerising polypropylene or copolymerising propylene with one or more comonomers selected from ethylene and C4 to C101-olefins to produce a polypropylene homopolymer or copolymer respectively having a double bond concentration of at least 0.1 per 10,000 carbon atoms, (11) irradiating the polypropylene with an electron beam having an energy of at least 5 MeV and at radiation dose of at least 5 kGray, and (iii) melting and mechanically processing the melt of polypropylene to form long chain branches on the polypropylene molecules.
摘要:
This invention relates to the use of a linear dialkyl peroxide having an hexyne or an hexene backbone, for producing a controlled rheology polypropylene heterophasic copolymer of melt index MI2 larger than 15 g/10 min, having simultaneously a very high impact resistance and a high flexural modulus.
摘要:
A method of processing polyethylene for use as an extruded blow molding resin to improve the properties and processability thereof is accomplished by modifying a polyethylene resin having a molecular weight distribution (Mw/Mn) of less than about 10. The modification is carried out by the addition of a free radical initiator to the resin during extrusion of the resin to increase the rheological breadth of the polyethylene from about 10% to about 60% compared to unmodified polyethylene resin extruded under similar conditions. In another aspect of the invention, a polyethylene resin having higher melt index is processed to provide a desired final melt index by the addition of a free radical initiator where it would otherwise be necessary to utilize a resin having lower melt flow, and which is more difficult to process. Improvements in color can also be obtained.
摘要:
The present invention relates to a soft polypropylene resin having a melt index falling in a specific range, prepared by melting and kneading a substantial propylene homopolymer or a propylene copolymer composition each having specific properties in the presence of a radical-generating agent. According to the present invention, capable of being provided at a good productivity is a soft polypropylene resin which is useful as an alternative for a polyvinyl chloride resin in the fields of films, sheets, construction materials and the like and which is excellent in fluidity.
摘要:
A method is described for the decomposition of polymers, especially waste plastics and used plastics, in which so-called NOR--HALS compounds--that is, for example, compounds comprising the group ##STR1## in which R* is C.sub.1 -C.sub.20 alkyl, OH-substituted C.sub.1 -C.sub.20 alkyl, optionally C.sub.1 -C.sub.4 alkyl-substituted C.sub.5 -C.sub.12 cycloalkyl or O- or S-interrupted C.sub.2 -C.sub.20 alkyl--are added and heating is carried out at temperatures which lie above the customary processing temperatures for polymers (280.degree. C. or more).
摘要:
A novel process for the production of degraded polyolefin is described. The process involves introducing polyolefin into one end of a vented multi-screw extruder, in the substantial absence of free radical initiator and oxidizing agent, and removing degraded polyolefin from the opposite end of the extruder.
摘要:
A blend and a process for producing that blend in which a high ethylene content ethylene-propylene polymer and a lower ethylene content ethylene-propylene polymer are subjected to simultaneous blending and shearing to reduce their molecular weights and molecular weight distribution. The sheared blend of polymers can function as a shear stable dispersant viscosity index improver with improved lower temperature properties or the hydrocarbon base for multifunctional for viscosity index improvers, motor fuel additives or polymeric dispersants.