Co- and terpolymerizations of ethene and ?-olefins with metallocenes

Abstract

The suitability of the (n‐butCp)2ZrCl2/methylaluminoxane (MAO) catalyst system for the copolymerization of ethene with propene, hexene, and hexadecene was studied and Ind2ZrCl2/MAO was tested as a catalyst for ethene/propene and ethene/hexene copolymerizations. The synergistic effect of longer α‐olefin on propene incorporation in ethene/propene/hexene and ethene/propene/hexadecene terpolymerizations was investigated with Et(Ind)2ZrCl2MAO and (n‐butCp)2ZrCl2/MAO catalyst systems. The molar masses, molar mass distributions, melting points, and densities of the products were measured. The incorporation of comonomer in the chain was further studied by segregation fractionation techniques (SFT), by differential scanning calorimetry (DSC), studying the β relaxations by dynamic mechanical analysis (DMA) and by studying the microstructure of some copolymers by 13C‐NMR. In this study (n‐butCp)2ZrCl2 and Ind2ZrCl2 exhibited equal response in copolymerization of ethene and propene and both catalysts were more active towards propene than longer α‐olefins. A nearly identical incorporation of propene in the chain was found for the two catalysts when a higher propene feed was used. A lower hexene feed gave a more homogeneous comonomer distribution curve than a higher hexene feed and also showed the presence of branching. In terpolymerizations catalyzed with (n‐butCp)2ZrCl2, the hexadecene concentrations of the ethene/propene/hexadecene terpolymers were always very low, and only traces of hexene were detected in ethene/propene/hexene terpolymers. With hexene no clear synergistic effect on the propene incorporation in the terpolymer was detected and with hexadecene the effect of the longer α‐olefin was even slightly negative. With an Et(Ind)2ZrCl2/MAO catalyst system both hexene and hexadecene were incorporated in the chain in the terpolymerizations. © 1997 John Wiley & Sons, Inc.

Ethylene−Propylene Copolymerization with 2-Arylindene Zirconocenes

“…The ability of the catalysts 1-3/MAO to incorporate propylene into ethylene-propylene copolymers can be correlated with the ratio of the corresponding reactivity ratios r p /r e ) k pp k ep / (k ee k pe ) (Table 2), greater numbers corresponding to higher ability to incorporate propylene. While it was previously found that unbridged catalysts are less efficient for propylene incorporation into EP copolymers than bridged ones, 24 we find that the unbridged bis(2arylindenyl) catalysts 1-and 2/MAO incorporate more propylene into copolymers than the ethylene-bridged bis(indenyl) catalyst 3/MAO.…”

“…Two other examples of r e r p > 1 for metallocenes include Chien's report of r e r p ) 1.5 for Cp 2 -HfCl 2 13 and Lehtinen and Lo ¨fgren's recent report of r e r p ) 2.51-2.75 for Ind 2 ZrCl 2 /MAO. 24 In contrast to 1/MAO (r e ) 3.8-5.4) and 2/MAO (r e ) 4.2-6.0), both of these systems have relatively high values for r e (r e ) 13 and 20, respectively), indicating a tendency to incorporate longer ethylene sequences.…”

The production of ethene/propene/5‐ethylidene‐2‐norbornene terpolymers using metallocene catalysts: Polymerization, characterization and properties of the metallocene EPDM

“…The terpolymers exhibited greater shear tan d peak at the glass-rubber transition. [17][18][19][20] A sensitivity. The chain stiffening effect of the bulky high-intensity of the peak at the b-transition cor-ENB groups in the polymer chain could explain the responds to a more amorphous material.…”

Effect of Co- and Non-Copolymerizable Lewis Bases in Propylene Polymerization with EtInd2ZrCl2/MAO

“…These poly-a-olefins can be tailor-made for specific applications by introducing functional groups in the hydrophobic main chain or at the end of each polymer chain. [3,4] Recently some pioneering work on the copolymerization of a-olefins with monomers containing functional groups has been reported. Aaltonen et al described the copolymerization of ethene or propene with 10-undecen-1-ol.…”

“…[4] Organoboranes at the end of a spacer unit can be incorporated into the main chain of polyolefins. [3] Due to the strong tendency of the heteroatoms to coordinate to the Lewis acidic metal center this type of copolymers is very hard to obtain with a reasonable activity and high molar mass. [5] Another route towards well defined functional-ized poly-a-olefins is to copolymerize a-olefins with asymmetrically substituted dienes.…”