Synthesis and properties of ABA propylene‐ethylene block copolymers

Prabhu, P.; Schindler, A.; Theil, Michael H.; Gilbert, R. D.

doi:10.1002/pol.1981.170190226

Cited by 24 publications

(6 citation statements)

References 7 publications

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“…In a living polymerization the rates of termination and chain transfer are negligible, relative to the rate of propagation . When these conditions are met, it is possible to attain polymer architectures such as block copolymers, star-shaped polymers, and end-functionalized polymers . Although reports of the living polymerization of olefins with transition metal catalysts can be traced to 1979, the majority of examples have been reported only within the past 5 years .…”

Section: Introductionmentioning

confidence: 99%

Ethylene Homopolymerization and Copolymerization with Functionalized 5-Norbornen-2-yl Monomers by a Novel Nickel Catalyst System

et al. 2003

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The homopolymerization and the copolymerization of ethylene with functionalized 5-norbornen-2-yl derivatives by the nickel catalyst system L(and Ni(COD)2 (bis(1,5-cyclooctadiene)nickel) produces polymers with high molecular weights and narrow molecular weight distributions. A typical ethylene polymerization reaction proceeds under 100 psi of ethylene and at 20 °C, using 1 (0.34 mM) and Ni(COD)2 (0.83 mM). Likewise, under similar conditions, the copolymerization of ethylene with 5-norbornen-2-yl acetate (3) (0.15 M) for 90 min by 1 (0.67 mM) and Ni(COD)2 (1.67 mM) produced a high molecular weight functionalized polyethylene bearing ester functionalities. 5-Norbornen-2-ol (0.15 M) underwent a similar copolymerization with ethylene for 20 min to yield a hydroxy-functionalized polyethylene. Narrow molecular weight distributions, coupled with the increase of polymer molar mass with time, are consistent with a quasi-living polymerization process in the case of ethylene homopolymerization and ethylene copolymerization with 3.

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Section: Introductionmentioning

confidence: 99%

Ethylene Homopolymerization and Copolymerization with Functionalized 5-Norbornen-2-yl Monomers by a Novel Nickel Catalyst System

et al. 2003

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“…Furthermore, it was demonstrated that the novel C(sp 3 )–C(sp 3 ) coupling reaction could be utilized for the construction of valuable ABA-type polyolefin triblock copolymers, which are expected to exhibit useful thermoplastic elastomer properties (Scheme ). − Typically, the number-average molecular weight ( M n ) attainable in CCTP is limited (∼60 kDa). This work provides a method to prepare high molecular weight POs in CCTP and overcoming this limitation.…”

Section: Introductionmentioning

confidence: 99%

Peroxide-Mediated Alkyl–Alkyl Coupling of Dialkylzinc: A Useful Tool for Synthesis of ABA-Type Olefin Triblock Copolymers

Kim

Kwon

et al. 2018

Macromolecules

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A practical and simple method for the preparation of ABA-type olefin triblock copolymers, e.g., PE-b-poly(ethylene-co-propylene)-b-PE, has been described. The performance of the so-called “coordinative chain transfer polymerization” (CCTP) by sequential feed of ethylene and ethylene/propylene mixed gas generated a Zn-bound diblock copolymer (i.e., (PE-b-poly(ethylene-co-propylene)yl)2Zn). Treatment of the Zn-bound diblock copolymer with lauroyl peroxide (CH3(CH2)10C(O)O-OC(O)(CH2)10CH3) led to a C(sp3)–C(sp3) coupling reaction between the two diblock chains bound on the zinc site and an ABA-type olefin triblock copolymer, PE-b-poly(ethylene-co-propylene)-b-PE, was formed. Upon the treatment with lauroyl peroxide, the number-average molecular weight increased by 1.5–1.7 times. The occurrence of the coupling reaction was verified using a model compound, (Oct)2Zn. The ABA-type triblock copolymer exhibited thermoplastic elastomeric properties and dramatically improved mechanical properties (twice the tensile strength and 10-fold increase in the elongation at break) as compared to the diblock congener.

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“…Though the preparation of PP/PE blends by multi‐stage polymerization was reported many years ago,11 the toughness–stiffness balance of the material seems not to be attractive, and commercialization of this kind of polyolefin is quite limited compared to PP/EPR in‐reactor alloy (so‐called block PP or PP‐b). Chain structure and physical properties of propylene‐ethylene sequential polymerization products, which were prepared by using TiCl 3 ‐based catalysts, have been studied by several groups 12–16. As the PP and PE homopolymer chains were not separated from the block copolymer chains in these studies, the structure of the components of the studied polyolefins were not identified on solid experimental bases.…”

Section: Introductionmentioning

confidence: 99%

Chain structure of polyethylene/polypropylene in‐reactor alloy synthesized in gas phase with spherical Ziegler–Natta catalyst

Fu¹,

Fan²,

Zhang³

et al. 2004

Polymer International

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Two polyethylene/polypropylene (PE/PP) in‐reactor alloy samples were synthesized by multi‐stage gas‐phase polymerization using a spherical Ziegler–Natta catalyst. The alloys show excellent toughness and stiffness. FTIR, 13C‐NMR and thermal analysis proved that the alloys are mainly composed of polyethylene, PE‐block‐PP copolymer and polypropylene. There are also a few percent of ethylene‐propylene segmented copolymer with very low crystallinity. The block copolymer fraction accounts for more than 25 % of the alloy. The role of the block copolymer as compatibilizer between PE and PP is believed to be the key factor that results in the excellent toughness–stiffness balance of the material. Copyright © 2004 Society of Chemical Industry

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Synthesis and properties of ABA propylene‐ethylene block copolymers

Cited by 24 publications

References 7 publications

Ethylene Homopolymerization and Copolymerization with Functionalized 5-Norbornen-2-yl Monomers by a Novel Nickel Catalyst System

Ethylene Homopolymerization and Copolymerization with Functionalized 5-Norbornen-2-yl Monomers by a Novel Nickel Catalyst System

Peroxide-Mediated Alkyl–Alkyl Coupling of Dialkylzinc: A Useful Tool for Synthesis of ABA-Type Olefin Triblock Copolymers

Chain structure of polyethylene/polypropylene in‐reactor alloy synthesized in gas phase with spherical Ziegler–Natta catalyst

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