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

Abstract

Vinyl addition copolymerization of norbornene with norbornene derivatives bearing siloxane substituent, three arm-, cyclicand phenyl-siloxane groups, was realized in the presence of the binary Ni(acac) 2 /B(C 6 F 5 ) 3 system. The resulting copolymers show good solubility in common organic solvents and possess a very high grass transition temperature between 265 and 360 C, depending on the content and structure of the siloxane groups. The incorporation of siloxane groups linked to the polymer chain results in a significant increase in the mechanical flexibility of the corresponding films. Furthermore, the gas permeability is also dependent on the content and structure of the siloxane groups, and the films obtained for the polymers with three arm-siloxane group (-Si(OSiMe 3 ) 3 ) display high oxygen permeability in the range of 39 to 239 Barrer.KEY WORDS: Polynorbornene / Siloxane Substituent / Copolymerization / Nickel Catalyst / Norbornene can be polymerized by three different methods: ring opening metathesis polymerization (ROMP), cationic or radical polymerization, and vinyl addition polymerization. 1Among these polymers, addition-type poly(norbornene), presenting the rigid bicyclic structure, is recently attracting strong interest in optical and opto-electronic device applications because of high optical transparency, low birefringence, very high glass transition temperature and low dielectric constant. However, poor solubility in common organic solvents and mechanical brittleness are serious disadvantages for the processing of the polymer materials. These problems can be improved markedly by copolymerizing a small amount of functional norbornene derivatives.So far, many types of poly(norbornene)s with functional groups have been prepared. [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.7-9 and Grove et al. 10 prepared alkyl-or alkoxysilyl-substituted poly(norbornene)s, which showed improved mechanical toughness and adhesion to common substrate materials. On the other hand, Dorkenoo et al. 11and Finkelshtein et al.12 investigated the homopolymers of norbornene derivatives bearing alkyl or alkylsilyl substituents, and demonstrated that the chain length and the bulkiness of the substituents played a decisive role in the transport properties, such as gas permeability and permselectivity, for the polymeric membranes. These results show that the nature of substituent and the content in the main chain are an important factor for the regulation of the material properties.Poly(siloxane) is a class of polymers that has practical importance in the consumer and indus...

Addition-type poly(norbornene)s with siloxane substituents: synthesis, properties and nanoporous membrane

“…Under these conditions, the catalytic system efficiently initiated homo-and copolymerizations of the NBs. As compared with the binary Ni(acac) 2 /B(C 6 F 5 ) 3 system used before, 13 the catalytic activity was more than 10 times higher, and the polymers were easily formed. The resulting polymers, except the PNBTr homopolymer obtained in run 3 (Table 1), were all soluble in toluene and tetrahydrofuran.…”

“…Such behavior is probably attributable to the formation of high-molecular-weight polymer. 13,17 In fact, even the solvent-soluble polymers have high molecular weights (M n ¼467 000-842 000) and narrow molecular weight distributions (M w /M n ¼1.24-1.52).…”

“…The 5-Si(OSiMe 3 ) 3 norbornene (NBTr), 5-{SiMe(OSiMe 3 ) 2 }norbornene (NBDi) and 5-{Si(Me)(Ph)(OSiMe 3 )}norbornene (NBPh) were prepared by Shin-Etsu Chemical Co. Ltd, Tokyo, Japan. 13 (Z 3 -Allyl)(Z 5 -cyclopentadienyl)palladium ((Cp)Pd(Allyl)) was prepared as described in the literature. 14 …”

“…The characterization of polymers was determined by 1 H NMR (proton nuclear magnetic resonance; 300 MHz) and 13 C NMR (Carbon-13 nuclear magnetic resonance; 75 MHz) in CDCl 3 with a JNM LA-300WB spectrometer (JEOL Ltd, Tokyo, Japan). Compositions of the obtained copolymers were calculated from 1 H NMR spectra on the basis of the peak intensities originating from the siloxane units.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] Previously, we prepared the addition-type poly(norbornene)s with siloxane (Si-O-Si) linkages, which showed improved solubility and mechanical flexibility. 13 In addition, the film for the polymer with Si(OSiMe 3 ) 3 groups was found to display high oxygen permeability (P(O 2 )¼39-239 Barrer), depending on the side group content. Recently, Finkelshtein et al 10 investigated the addition polymerization of a NB derivative bearing SiMe 3 groups and showed that the resulting polymer possessed both high thermal stability and excellent gas permeability (P(O 2 )¼980 Barrer).…”