Bimodal polyethylene– Interplay of catalyst and process

Creep behavior of high density polyethylene after aging in contact with different oil derivates

“…On the long term, this kind of polymer is also characterized by a good resistance to stress cracking. At least, the processability is also easier what can be related to the fact that the polymer chains with low molecular weight act as a plasticizer [25][26][27][28]. Figure 9 depicts the relative weight variation of the polymer samples as a function of aging time and for the different immersion fluids at the temperature T ¼ 258C.…”

Observation of bimodal polyethylene derived from TiO2-supported zirconocene/MAO catalyst during polymerization of ethylene and ethylene/1-hexene

“…Hence, the bimodal MW can provide both enhanced rheological and mechanical properties. In general, there are some techniques used to produce the bimodal MW polymer such as; (i) stepwise polymerization [9], (ii) polymerization using a mixture of two catalysts [10][11][12] for generating the dual sites, and (iii) a sudden variation of reaction conditions [13] for controlling the chain transfer reaction. In this present study, we revealed an alternative way to produce the bimodal PE with TiO 2 -supported zirconocene/MAO catalytic system.…”

Separation of bimodal high density polyethylene using multidimensional high temperature liquid chromatography

“…[1]. BiHDPE is synthesized in a cascade process, where the first reactor is fed with ethylene and hydrogen to produce an unbranched PE of low molar mass.…”

“…BiHDPE is synthesized in a cascade process, where the first reactor is fed with ethylene and hydrogen to produce an unbranched PE of low molar mass. The hydrogen is then removed, and the resulting product is transferred to a second reactor, where a 1-alkene (1-butene or 1-hexene) is added as comonomer to produce a high molar mass short chain-branched copolymer [1][2][3]. Typically, this second reactor product is characterized by a comonomer distribution over the molar mass distribution such that the highest comonomer contents are found in the lower molar masses.…”