Synthesis of Vinyl-Addition Polynorbornene Copolymers Bearing Pendant n-Alkyl Chains and Systematic Investigation of Their Properties

Abstract

The synthesis of vinyl-addition polynorbornene copolymers bearing pendant n-alkyl chains (octyl, decyl, and dodecyl groups) and systematic investigation of their properties are reported. Vinyl-addition polymerization using Pd2(dba)3/PCy3/Li­[FABA] produces poly­(norbornene-co-5-n-alkyl-2-norbornene)­s, P­(NB/NBCx) (x is the number of carbon atoms in the n-alkyl chain), with a high weight-average molecular weight (M w) of 71.2–410.6 kDa, high yields of 68–87%, and a similar monomer content to the monomer feed ratio. The films of the resulting copolymers are successfully prepared by a solution-casting method. The glass transition temperature (T g) of these films can be tuned from 91.7 to 192.4 °C depending on the length of the alkyl chain of NBCx and the NBCx content. The mechanical properties are controlled by these two parameters as well. The change from brittle to ductile properties is observed with the increasing NBCx content of P­(NB/NBCx) films, where the increase in the length of the alkyl chain of NBCx increases the value of the strain at break, accompanied by a decrease in strength. The wide-angle X-ray scattering analysis provides information on nanostructure–property relationships in copolymers. All P­(NB/NBCx) films display a high transmittance of more than 85% in the visible-light range.

Bis(β-ketoimino)nickel(II) Complexes for Random Copolymerization of Norbornene and Methyl 5-Norbornene-2-carboxylate with Controlled Ester Group Incorporation

“…This effect could improve the mobility of the bicyclic backbone, thereby allowing for reorganization of the copolymer chains with deformation. A similar pendant effect has been demonstrated in a previous study using copolymers of NB and alkyl-functionalized NB …”

“…This effect could improve the mobility of the bicyclic backbone, thereby allowing for reorganization of the copolymer chains with deformation. A similar pendant effect has been demonstrated in a previous study using copolymers of NB and alkyl-functionalized NB 54. ■ CONCLUSIONSWe developed new bis(β-ketoimino)nickel(II) complexes with p-substituted N-phenyl groups, Ni[CH 3 C(O)CHC(NPhR)-CH 3 ] 2 (Ni1: R = −OCH 3 ; Ni2: R = −CH 3 ; Ni3: R = −CF 3 ), for NB/NBE copolymerization with a high capability of controlled ester group incorporation.…”

“…Two broad diffraction peaks at 2θ = 9.72°–10.14° and 2θ = 19.05°–19.09° were assigned to the intersegmental and intrasegmental distances of P­(NB- r -NBE) chains, respectively. Both peaks are typical of PNB-based copolymers. ,,− ,, Noticeably, the diffraction peak at lower 2 θ shifted gradually from 10.14° to 9.72° as the NBE content increased from 8.8 to 50.4 mol %, indicating an increase in the intersegmental distance with the introduction of methyl ester pendants. , …”

“…3,37,[40][41][42]53,54 Noticeably, the diffraction peak at lower 2θ shifted gradually from 10.14°to 9.72°as the NBE content increased from 8.8 to 50.4 mol %, indicating an increase in the intersegmental distance with the introduction of methyl ester pendants. 53,54 The thermal properties of the P(NB-r-NBE)s with 8.8, 26.6, and 50.6 mol % NBE were studied using TGA and DSC at a heating rate of 10 °C min −1 under the nitrogen atmosphere. The TGA thermograms of all three copolymers exhibited onestep thermal decomposition in the temperature range of 400− 500 °C (Figure 5).…”

Thermal‐stable asymmetric α‐diimine nickel(II) catalysts: Synthesis, characterization, and its norbornene (co)polymerization behavior

“…Vinyl‐addition‐type polynorbornene (PNB) possesses many excellent performances, such as good chemical resistance, thermal resistance and UV resistance, and outstanding optical transparency. [ 1–5 ] However, it also exhibits poor processability and solubility, which seriously limit its application. In order to overcome these drawbacks, polar vinyl monomers and polar norbornene derivatives were always employed as comonomer during the polymerization processes to prepare functionalized PNBs.…”