No abstract

Illb 7.30 (8.0) °All spectra run on Varían A-60 spectrophotometer. Chemical shifts given in parts per million relative to tetramethylsilane as internal standard.6 All peaks are singlets. Relative peak areas correspond to number of protons in each group. 'All doublets; area = 2. "'Coupling constants (J) in cps. J values are JHiHs = =/ 6 where aromatic rings are numbered starting with carbon bearing carbomethoxy or carboxy substituent in all cases.We acknowledge the assistance of Larry Echelberger.

Fully acetylated cotton (FA cotton), a chemically modified cellulosic fiber made from cotton and retaining its fibrous form, is described. A small-scale method of preparing a completely or nearly completely substituted product from cotton raw stock, yarn, or fabric by the application of acetic anhydride and perchloric acid catalyst in a diluent which minimizes the tendency of the product to dissolve, is reported. Its general properties and behavior in laboratory tests show it to have many superior properties to previously known cellulosic fibers, including partial acetates and triacetates. FA cotton has good tenacity, both wet and dry, and flex-abrasion endurance; it has some thermoplasticity, yet shows no sticking at ironing temperatures below 250° C.; it has low moisture regain and is dyeable with ordinary acetate colors. Work in progress mdicates that treatment of yarn and fabric may be carried out satisfactorily in commercialtype stainless steel equipment.