摘要:
Continuity compositions are provided as are methods of their preparation. The compositions comprise at least one metal carboxylate salt which is modified with at least one molten fatty amine. These compositions find advantageous use in olefin polymerization processes.
摘要:
The invention relates to a bimodal linear medium density polyethylene composition comprising a lower molecular weight (LMW) polyethylene component and a higher molecular weight (HMW) polyethylene component, wherein each of the LMW and HMW polyethylene components comprises ethylene-derived monomeric units and (C 3 -C 20 )alpha-olefin-derived comonomeric units; and wherein the bimodal linear medium density polyethylene composition is characterized by each of limitations (a) to (d): (a) a resolved bimodality showing in a chromatogram of gel permeation chromatography (GPC) of the bimodal linear medium density polyethylene composition, wherein the chromatogram shows a peak representing the HMW polyethylene component, a peak representing the LMW polyethylene component, and a resolved bimodal molecular weight distribution characterized by a local minimum in a range of Log(molecular weight) ("Log(MW)") 1.5 to 5.0 between the peak representing the HMW polyethylene component and the peak representing the LMW polyethylene component, measured according to Bimodality Test Method; (b) a molecular mass dispersity (M w /M n ), Ð M , from 5 to 30.1, measured according to Gel Permeation Chromatography (GPC) Test Method; (c) no measurable amount of long chain branching per 1,000 carbon atoms ("LCB Index"), measured according to LCB Test Method; and (d) a density from 0.930 to 0.950 gram per cubic centimeter (g/cm 3 ), measured according to ASTM D792-13 Method B.
摘要:
The catalyst productivity of a polyolefin catalyst in the methods disclosed herein may be increased by increasing the concentration of an induced condensing agent (ICA) in the reactor system. The effect the increased ICA concentration may have on a melt index may be counteracted, if necessary, in various ways.
摘要:
Methods for producing polyolefin polymers may use a predictive melt index regression to estimate the melt index of the polyolefin during production based on the composition of the gas phase and, optionally, the concentration of catalyst in the reactor or reactor operating conditions. Such predictive melt index regression may include multiple terms to account for concentration of ICA in the reactor, optionally concentration of hydrogen in the reactor, optionally concentration of comonomer in the reactor, optionally the catalyst composition, and optionally reactor operating conditions. One or more terms may independently be represented by a smoothing function that incorporates a time constant.
摘要:
Embodiments of the present disclosure are directed towards method for modifying a polymer flow index. As an example, a method for modifying a polymer flow index can include providing monomers to a polymerization reactor, providing a chromium catalyst to the polymerization reactor, and providing an active amount of a flow index modifier to the polymerization reactor, wherein the flow index modifier is selected from carbon dioxide, carbon monoxide, 2,4-hexadiene, and combinations thereof.