Propylene/Cyclic Olefin Copolymers with Cyclopentene, Cyclohexene, Cyclooctene, Tricyclo[6.2.1.0(2,7)]undeca-4-ene, and Tetracyclododecene: The Synthesis and Effect of Cyclic Structure on Thermal Properties

Abstract

Propylene (P) copolymers with a series of cyclic olefins [cyclopentene (CPE), cyclohexene (CHE), cis-cyclooctene (COE), tricyclo­[6.2.1.0­(2,7)]­undeca-4-ene (TCUE), and tetracyclododecene (TCD)] have been prepared in toluene in the presence of phenoxide-modified half-titanocene catalysts, especially Cp’TiCl2(O-2,6- i Pr2C6H3) (Cp’ = 1,2,4-Me3C5H2, t BuC5H4), and methylaluminoxane (MAO) cocatalyst. The resultant copolymers are amorphous materials, and their compositions were uniform as confirmed by DSC thermograms [sole glass transition temperatures (T g)]. The cyclic olefins were incorporated in a 1,2-insertion manner, and the incorporation was affected by the kind of cyclic olefin as well as the nature of catalysts employed. The CHE contents in the copolymers were up to 6.3 mol % (incorporated in an isolated manner), whereas the CPE, COE, TCUE, and TCD contents in the copolymers increased up to ca. 40 mol % (with a mixture of isolated and alternating incorporations) with an increase in the comonomer concentration charged. Linear correlations between T g values and cyclic olefin contents were demonstrated in all copolymers. The cyclic structure affects the T g values in the propylene copolymers, except that plots of T g values vs cyclic olefin contents were close in the P/CPE and P/COE copolymers. In the low cyclic olefin content region (up to 25 mol %), the T g values in the propylene copolymers were higher than those in the ethylene copolymers.

Dinuclear Half-Titanocene Complex Bearing an Anthracene-Bridged Bifunctional Alkoxide Ligand: Unprecedented Cooperativity toward Copolymerization of Ethylene with 1-Octene or Norbornene

“…The latter leads to production of COCs, which are attractive engineering plastics with high performances, including high transparency in the ultraviolet–visible (UV–vis) region (amorphous material), good thermal resistance (high T g ), and extremely low water absorption (excellent water vapor barrier properties) . Many catalytic systems, such as conventional metallocene, − constrained geometry catalyst (CGC), , nonbridged half-titanocene, and nonmetallocene, , have been reported for the copolymerization of ethylene with cyclic olefins, especially with norbornene (NBE). However, successful catalysts that can produce COCs with random structures, high molecular weights ( M w s), narrow distributions, and high T g values (high NBE contents) are still limited …”

Copolymerization of tricyclopentadiene and ethylene catalyzed by thiophene-fused-heterocyclic cyclopentadienyl scandium complexes

“…[1][2][3][4] The cyclic olefin monomers used in COC synthesis are mainly norbornene (NB), [5][6][7][8][9][10][11][12][13][14][15][16][17][18] dicyclopentadiene (DCPD) [19][20][21][22][23][24][25] and their derivatives. 2,[26][27][28] COCs with functiona-lized CvC double bonds have been produced via vanadiumbased catalysts. 29,30 NB and 1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene (DMON)-based COC materials (NB/E and DMON/E copolymers) have been applied industrially and showed extensive application potential in optical and medical appliances.…”

“…Normally, raising the cyclo-olefin incorporation into copolymers and using larger cyclic olefin monomers are efficient methods for increasing the T g of COCs. 8,26 However, the cyclo-olefin contents of COCs currently exhibit maximum for certain monomers. In addition, too much incorporation of cyclic monomers would result in serious brittleness for the raw materials and manufactured products.…”

Combining Cyclic Units and Unsaturated Pendant Groups by Propene/1,5-Hexadiene Copolymerization Toward Functional Isotactic Polypropylene

“…Isotactic polypropylene (iPP) is a paradigmatic case among polyolefins of widespread use and commercial success due to its unique combination of exceptional physical properties, high chemical resistance, low weight, and, in particular, cost-effectiveness. − However, its low impact resistance, especially at low temperatures, has limited the use of iPP in certain applications. , The incorporation of comonomers as several more or less longer linear α-olefins (e.g., 1-butene, 1-pentene, 1-hexene, etc.) into the polypropylene backbone is one of the widely adopted strategies to address this shortcoming. ,− The copolymerization of propylene with linear α-olefins has been, indeed, extensively explored, and the effect of the incorporated constitutional irregularities of different bulkiness on the crystallization behavior and mechanical properties of iPP has been deeply studied, in particular, for model copolymers prepared with single-site metallocene catalysts. − Equivalent attention has not been given to the copolymerization of propene with cyclic olefins. − Copolymers of cyclic olefins (COCs) are recognized for their unique properties, including good heat and chemical resistance, low dielectric constants, non-hygroscopicity, and high transparency. − …”