LY[PROPYLENE-GRAFT-(4-VINYLPYRIDINIUM-DICHROMATE)] - A NOVEL FIBROUS POLYMER-SUPPORTED OXIDIZING-AGENT

Polypropylene nonwoven fabrics were radiation grafted with 4-vinylpyri dine and then functionalized with chromium trioxide to obtain the corr esponding poly[propylene-graft-(4-vinylpyridinium dichromate)]. The de gree of functionalization was found to be in the range of 80-90% of th e theoretical value. The insoluble functionalized polymer substrate po ssesses the desired characteristics of a useful polymer-supported reag ent, including high accessibility of active sites and operational simp licity. The oxidation of alcohols was investigated to compare this pol ymer-substrate supported reagent with a commercially available cross-l inked poly(vinylpyridinium) reagent. The reagent supported on the nonw oven fabric was found to be more efficient in the oxidation reactions than the commercially available poly(vinylpyridinium) reagent. This di fference in reactivity is attributed to the non-cross-linked graft cha ins in the nonwoven supported reagent, which increase the accessibilit y to the active sites. The reagent is very easily separated from the r eaction mixture since the fabric can be manually removed from the solu tion, which remains clear during and after the reactions.