Copolymerization of ethylene or propylene with α‐olefins containing hydroxyl groups with zirconocene/methylaluminoxane catalyst

Abstract

Copolymerization of olefins (ethylene and propylene) and 5‐hexen‐1‐ol pretreated with alkylaluminum was performed using [dimethysilylbis(9‐fluorenyl)]zirconium dichloride/methylaluminoxane as the catalyst. The copolymerization required extra addition of alkylaluminum to prevent deactivation of the catalyst when 5‐hexen‐1‐ol was pretreated with trimethylaluminum, whereas the triisobutylaluminum‐treated system did not require any addition of alkylaluminum. The molecular weight of the copolymer depended on the kind of alkylaluminum compound (masking reagent, additive, and cocatalyst). 13C NMR analysis proved that poly(ethylene‐co‐5‐hexen‐1‐ol) containing 50 mol % of 5‐hexen‐1‐ol acted as an alternating copolymer, whereas the poly(propylene‐co‐5‐hexen‐1‐ol) acted as a random copolymer. The surface property of the copolymers was simply evaluated by means of water drop contact angle measurement. It was found that the copolymers containing large amounts of 5‐hexen‐1‐ol units showed good hydrophilic properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 52–58, 2004

Macromolecular Non‐Releasing Additives for Commercial Polyolefins

“…[5] Nevertheless we have decided to explore the copolymerization of ethylene with comonomers derived from BHA, for the reason that BHA shows a higher antioxidant activity compared with BHT. Indeed, the measured O-H BDE (Bond Dissociation Enthalpy) for BHT and BHA are 81 and 78 kcal/mol, [6] while their k inh in the auto-oxidation of hydrocarbons (like styrene) are 1 Â 10 4 and 3 Â 10 5 mol À1 s À1 , respectively.…”

“…Triisobutylaluminium (TIBA) was used to prevent the catalyst deactivation: the phenol was pretreated with 2 equivalents of TIBA, in order to protect the hydroxy group and interact with the ether oxygen. [5] The polymerizations were performed at 0.3 atm of ethylene gas pressure to promote the insertion of the bulky polar comonomer with respect to ethylene. Table 1 reports the polymerization results along with the microstructural and molecular characterization of copolymers.…”

Reactivity Comparison of ω-Alkenols and Higher 1-Alkenes in Copolymerization with Propylene Using An Isospecific Zirconocene-MMAO Catalyst

“…All comonomers (Chem Greatwall, Wuhan, China) were dried over calcium hydride and freshly distilled before use. TIBA-protected ω-alkenols were prepared according to literature [13]. Zirconocene ([Me 2 Si(2-Me-4-Ph-Ind) 2 ]ZrCl 2 ) was obtained from Boulder Scientific company (Longmont, CO, USA) and used without further purification.…”

“…The content of the polar comonomer can be calculated from the integral ratio of -CH 2 OH methylene proton at 3.63 ppm in 1 H NMR spectrum [27]. The typical 13 C NMR spectrum of non-functional copolymer was shown in Figure 1B, and the content was calculated according to the published literature [31].…”

“…The copolymerization of ethylene with alkylaluminum-protected polar comonomer has been studied extensively for the synthesis of functionalized polyethylene bearing alcohol [7][8][9][10][11][12][13][14][15][16][17][18], ester [8,9,19,20], ether [10,21], and acid functionalities [8,9,11,17]. However, the copolymerization activity of almost all of these catalytic systems dropped significantly compared to the homopolymerization of ethylene.…”