Cellulose mechanoradicals

Mechanochemically Initiated Graft Copolymerization. According to the ESR study, it is clear that mechanoradicals were generated in cellulose either by means of mechanical cutting or ball milling. These mechanoradicals may be utilized as reaction sites for the initiation of vinyl polymerization which would result in graft copolymerization of cellulose. Based on this principle, the ability of cellulose mechanoradicals to initiate copol3nnerization was pursued. 

Figure 7. Changes in ESR spectra of cotton cellulose mechanoradicals. Key a, initial spectrum observed at 77 K immediately after milling for 4 h at 298 K b, cotton cellulose after milling was contacted with methyl methacrylate and warmed at 298 K for 2 min c, 5 min d, 10 min recorded at 77 K.

Cotton cellulose is susceptible to degradation by mechanical shear forces supplied by either a Wiley mill or a Norton ball mill. Mechanoradicals are produced in the interim. 

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