This work aimed at investigating the feasibility of surface modification of cellulose nanocrystals (CNCs) using <em>in situ</em> ring opening polymerization of <em>ε</em>-caprolactone (<em&...This work aimed at investigating the feasibility of surface modification of cellulose nanocrystals (CNCs) using <em>in situ</em> ring opening polymerization of <em>ε</em>-caprolactone (<em>ε</em>-CL) at room temperature. Residues of flax and milkweed (<em>Asclepias syriaca</em>) stem fibers were used as a source of cellulose to obtain and isolate CNCs. The cationic ring opening polymerization (CROP) of the monomer <em>ε</em>-CL was used to covalently graft polycaprolactone (PCL) chains at the CNCs surface. Silver hexafluoroantimonate (AgSbF<sub>6</sub>) was used in combination with the extracted CNCs to initiate, at room temperature, the polymerization and the grafting reactions with no other stimulus. Fourier-Transform InfraRed (FTIR), X-ray Photoelectron Spectrometry (XPS), UV/visible absorption and Gel Permeation Chromatography (GPC) analyses evidenced the presence of PCL chains covalently grafted at CNCs surface, the formation of Ag(0) particles as well as low or moderate molecular weight free PCL chains.展开更多
文摘This work aimed at investigating the feasibility of surface modification of cellulose nanocrystals (CNCs) using <em>in situ</em> ring opening polymerization of <em>ε</em>-caprolactone (<em>ε</em>-CL) at room temperature. Residues of flax and milkweed (<em>Asclepias syriaca</em>) stem fibers were used as a source of cellulose to obtain and isolate CNCs. The cationic ring opening polymerization (CROP) of the monomer <em>ε</em>-CL was used to covalently graft polycaprolactone (PCL) chains at the CNCs surface. Silver hexafluoroantimonate (AgSbF<sub>6</sub>) was used in combination with the extracted CNCs to initiate, at room temperature, the polymerization and the grafting reactions with no other stimulus. Fourier-Transform InfraRed (FTIR), X-ray Photoelectron Spectrometry (XPS), UV/visible absorption and Gel Permeation Chromatography (GPC) analyses evidenced the presence of PCL chains covalently grafted at CNCs surface, the formation of Ag(0) particles as well as low or moderate molecular weight free PCL chains.
