Pd (II)‐catalyzed vinyl addition polymerization of novel functionalized norbornene bearing dimethyl carboxylate groups

Abstract

Three novel functionalized polynorbornenes (PNB) with pendant dimethyl carboxylate group (carboxylates—acetate, propionate, and butyrate) are synthesized as a vinyl‐type with a palladium (II) catalyst in high yield. The effects of size of substitutents, molar ratio of monomer to catalyst, solvent polarity, reaction time, and temperature on the polymerization of exo‐norbornene dimethyl propionate were systematically investigated. The low molar ratio and temperature, as well as high polarity of solvent, and long reaction time, are favorable for the enhancement of the monomer conversion, especially, the solvent have an obvious effect on the catalyst activity. The resulting poly(cis‐norbornene‐exo‐2,3‐dimethyl carboxylates) (PNB‐dimethyl carboxylates) show good solubility in common organic solvent and high thermal stability up to 360 °C. The glass transition temperature was detected by DMA at 331, 324, and 318 °C for acetate, propionate, and butyrate, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3391–3399, 2007

Metal catalysts for the vinyl/addition polymerization of norbornene

“…Hence, the polymerization of substituted derivatives proceeds slower than in the case of the unsubstituted norbornene monomer [77,78]. Examples for the polymerization of substituted norbornenes are given in [77][78][79][80][81][82][83][84][85].…”

Addition polymerization of 5-ethylidene-2-norbornene by cationic palladium cationic complex and subsequent derivatization

“…12,15,[17][18][19] Thus, we investigated the ENB polymerizations in two kinds of solvents: toluene and DCE. In agreements with our previous findings, polar DCE was the better reaction medium, giving 84.2% conversion in 6 h at 60 o C at ENB/ Pd =10,000 molar ratio, while the conversion was 47.5% in toluene at the same conditions.…”

“…Many kinds of functional groups have been introduced into PNB as pendant chain such as alkoxysilyl, 1,2 alkyl, 2-8 ester [9][10][11][12][13][14][15][16][17] and imide groups [18][19][20] substantially enhancing the adhesion to surface, elongation at break and solubility in common organic solvents to some extent, enabling this class of polymer to be utilized for a wide variety of potential application. However, most of functionalized NB monomers are not produced in industry, limiting its extensive use.…”

“…30 Considering this important point, di-µ-chloro-bis(6-methoxybicyclo [2,2,1]hept-2-ene-endo-5σ, 2π)-palladium(II) associated with weak counter ions SbF 6 -(Complex I) (Figure 1) was selected as a catalyst to test its polymerization behavior of ENB because of its greater tolerance to NB derivatives containing various functional pendant groups. 12,15,[17][18][19] The ENB monomer was chosen because it bears a reactive substituent that can be utilized for further modification and it is commercially available. During the addition polymerization with Complex I, the attention was paid mainly on following aspects: i) the effect of reaction parameters on the homopolymerization of ENB, ii) the investigation the mechanism of the reaction of ENB with Complex I, and iii) DOI 10.1007/s13233-011-1011-9 *Corresponding Authors.…”

Palladium(II)-catalyzed addition polymerizations of nadimides with linear alkyl and alicyclic pendant groups

“…Thus, much effort has gone into surmounting these limitations by incorporating functional pendant groups into the PNB backbone, such as alkoxysilyl, alkyl, and ester groups. The key problem with this approach, however, is that these modifiers often deteriorate the thermal stability [5][6][7] and/or dielectric properties of the polymers. Unfavorable changes to these properties are undesired for certain applications, like interlayer dielectric materials.…”