Modification of Polyolefins by Click Chemistry

Abstract

Side chain modification of polyolefins applying a copper‐mediated “click chemistry” strategy is described. First, a bromo‐functionalized polyethylene (PE‐Br) are synthesized via ring‐opening metathesis polymerization of cis‐cyclooctene followed by quantitative hydrobromination. Subsequently, the bromide moieties of the functional PE‐based polymer are converted into azide groups via simple nucleophilic substitution. Success of the click reaction is demonstrated by using low molar mass and polymeric alkyne functional click components, namely pyrene alkyne and polystyrene alkyne, respectively. The intermediates at various stages and final polymers are characterized by 1H NMR, Fourier transform infrared, Gel permeation chromatography, and differential scanning calorimetry analysis.

Polypropylene-based graft copolymers via CuAAC click chemistry

“…As can be seen that the disappearances of characteristic alkyne and azide peaks; methine (c) 4.7 ppm and methylene (d) protons at 2.5 ppm of PCL-alkyne and methine (a) and methylene (b) as well as the appearance of triazole proton (c) at 8.12 ppm were great evidences for the successful formation of clicked product PP-g-PCL [54]. Also in Figure 5, the structure of another PPg-PEG copolymer was also analyzed by 1 H-NMR spectroscopy and the similar results were observed [45,[55][56][57][58]. Furthermore, the composition of graft copolymers were also calculated from integration ratios of specific resonances belonging to each segments by using following formulas Equations (1) and (2) for PP-g-PCL and PP-g-PEG and the result summarized in Table 1.…”

“…According to a typical azidation procedure [45]; PPCl (1.0 g, 2·10 -2 mmol) was dissolved in THF (5 mL) and added in a 20 mL one necked flat bottomed flask, equipped with magnetic stirrer bar. Then, the TMS-N 3 (0.2 mL, 1.7 mmol) and TBAF (0.5 mL, 1.5 mmol) were added by drop-wise, respectively.…”

Synthesis of Propargyl‐Terminated Polybutadiene and Properties of Polytriazole Elastomers

“…Copper (I)catalyzed 1,3-dipolar cycloaddition of triazole ring between acetylene (-C�CH) and azide (-N 3 ) (CuAAC) [6,7] is the most representative reaction in click chemistry and has been extensively utilized in many fields. Up to now, the literatures about CuAAC on polymer surface modification [8][9][10], syn-thesis and modification of functional polymers [11][12][13], biomarker [14][15][16], carbon nanotubes [17][18][19], biomedical synthesis [20][21][22], and genetic engineering [23,24], have been published.…”

Synthesis of graft copolymers by combination of radical photopolymerization and iniferter process

“…Recently, others and we have reported numerous transformation methods associating conventional free‐radical systems with different anionic, cationic, and condensation polymerizations . Particularly, polyolefin‐based graft copolymers were fabricated by the combination of ROMP and other polymerization and functionalization techniques by either “grafting from” or “grafting to” approaches in our laboratory (Scheme ) . Different groups have also utilized photochemical approaches for the synthesis of graft copolymers to take advantage of the unique features of light induced systems such as temporal and spatial control, temperature independency, and low energy consumption .…”