Transition‐metal‐catalyzed vinyl addition polymerizations of norbornene derivatives with ester groups

Abstract

Norbornene derivatives containing ester substituents were submitted to Pd(I1)-catalyzed vinyl addition polymerization. The transition metal catalyst was found to tolerate the ester functionality. However, the rate of polymerization was reduced in comparison to the polymerization of norbornene. The polymerization of the pure exo-isomers produced substantially higher yields than reactions of monomers containing a high proportion of the corresponding endo-isomer. By varying the ester substituent, amorphous polymers with glass transition temperatures over the range of -40 to 268 "C were synthesized. An approximately linear relationship of molecular weight to monomer conversion was established, and the non-uniformity remained narrow (u,/a,, = 1,15-1,25) until high conversions for several of the exo-isomers studied. This indicates that both chain transfer and chain termination are rare. S. Breunig, W. RisseThe present study describes the synthesis of poly(S,6-bicyclo[2.2.l]hept-5-ene)derivatives with ester substituents in position 2. Polymers with appropriate substituents were expected to have good solubility in organic solvents and lower glass transition temperatures than the parent, unsubstituted polymer 3. Results and discussionEsters of bicyclo[2.2. Ilhept-5-ene-2-methanol (4ah) were polymerized by [Pd(CH,CN),] [BF412 in nitromethane at 25 "C, resulting in the corresponding vinyl addition polymers 5a-h (Eq. (1)). In contrast to the vast majority of transition metal catalysts used for insertion polymerizations '), the Pd2+ -based catalyst tolerates the presence of functional groups, such as ester and nitro groups.The polymer yields were only moderate, i.e., in the range of 22-32'4'0, when norbornene derivatives 4a-h with a low exo/endo ratio of 20/80 were used for polymerization (lkb. 1). Predominantly the exo-isomer underwent the polymerization reaction.An increase in molecular weight was observed when higher mole ratios of monomer/Pd(II)-catalyst were used for polymer synthesis; e. g., the molecular weight I % ? " (GPC) of 5 b increased from 5900 to 32000 upon increasing [M]/[I] from 100/1 to 900/1. However, the molecular-weight distributions MW/@,, (in the range of 1,6 to 2,5) were considerably broader than those of the unsubstituted poly(2,3-bicyclo-[2.2.l]hept-2-ene) (3) prepared under similar reaction conditions7).

Synthesis and Properties of Addition-Type Poly(norbornene)s with Siloxane Substituents

“…The endo/exo-molar ratios of the monomers were determined by integration of the proton resonances of distinct peaks (6.10-5.70 ppm: -CH=CH-) (see Figure 2). 4 These monomers were degassed under nitrogen and dried over 4 Å molecular sieves prior to polymerization.…”

“…[2][3][4][5][6][7][8][9][10][11][12][13] Heitz et al 2,3 investigated the addition-type copolymerizations of norbornene with norbornene carboxylic acid esters, and found that the solubility of the copolymers and the thermal properties, such as glasstransition and decomposition temperatures, were dependent on the content as well as structure of the substituents. Risse et al [4][5][6] came to the same conclusion by studying poly-(norbornene)s containing hydroxyl, carboxylic acid and ester. Goodall et al [7][8][9] and Grove et al 10 prepared alkyl-or alkoxysilyl-substituted poly(norbornene)s, which showed improved mechanical toughness and adhesion to common substrate materials.…”

Polymerization of 1,3-Butadiene with NiCl2 in Combination with Methylaluminoxane

“…Among transition metals catalyzed the polymerization of Bd, Ni-based catalysts are interesting ones from the viewpoints of not only polymerization capabilities for versatile monomers such as cyclic olefins [1][2][3][4] , ethylene or 1-olefins [5][6][7][8][9] , styrene and its derivatives [10][11][12][13][14] , conjugated dienes [15][16][17][18] , and methacrylic monomers [19][20][21] but also an advantage to require a lesser amount of methylaluminoxane (MAO) as a cocatalyst to reach a high activity for the polymerization as compared with metallocene catalysts 7,[10][11][12][13][14][15][16][17][18][19][20] . The polymerizations of many monomers such as styrene 11) , Bd 17) , isoprene 18) , methyl methacrylate 19) with Ni(acac) 2 /MAO catalyst proceeded.…”

Structural analysis of thin films of novel polynorbornene derivatives by grazing incidence X-ray scattering and specular X-ray reflectivity along with ellipsometry

“…A representative cyclic olefin polymer is polynorbornene (Angiolini et al, 2003;Bhusari et al, 2001;Breunig & Risse, 1992;Byun et al, 2006;Grove et al, 1999;Heinz et al, 1998;Lipian et al, 2002;Mathew et al, 1996;Reinmuth et al, 1996;Shick et al, 1998). However, this polymer exhibits very low solubility in common organic solvents and poor processibility, as well as interfacial adhesion failure, making it unsuitable for use in applications such as flexible flat panel displays and microelectric and microfluidic devices.…”

“…However, this polymer exhibits very low solubility in common organic solvents and poor processibility, as well as interfacial adhesion failure, making it unsuitable for use in applications such as flexible flat panel displays and microelectric and microfluidic devices. Therefore, much research effort has been devoted to modifying this polymer via chemical functionalization and copolymerization so as to improve its solubility, processibility and interfacial adhesion properties (Breunig & Risse, 1992;Byun et al, 2006;Grove et al, 1999;Heinz et al, 1998;Reinmuth et al, 1996;Shin et al, 2004). As part of these efforts, a series of poly(norbornene carboxylic acid ester)s with high solubility were developed, and their mechanical, optical and electrical properties were investigated (Breunig & Risse, 1992;Mathew et al, 1996;Reinmuth et al, 1996;Heinz et al, 1998;Grove et al, 1999).…”