Vol. 70Mass Copolymerization.-The method for determining monomer-polymer composition curves for the five systems reported was essentially the same in each case. Solutions comprising 100 g. of total monomers were prepared by adding appropriate amounts of monomer, comonomer and benzoyl peroxide to 4-oz. French square bottles. The concentrations employed are given in Table I. Air above the monomers was swept out with nitrogen and a metal cap screwed tightly on the bottle mouth. Copolymerizations were carried out in an air oven regulated to ±1°w ithin the polymerization temperature given in Table I. Polymerization at that temperature was continued until a slight increase in viscosity was observed or, in the case of copolymer samples high in combined nitrile, until a small amount of insoluble copolymer had precipitated from the comonomer solution. The reaction was then poured into 3000 ml. of stirred denatured ethanol (2B) at room temperature and the bottle rinsed with ethanol.In the case of vinyl acetate copolymers, hexane was used in place of ethanol throughout. The mixture was boiled to complete the coagulation and filtered. Final purification was effected by similar treatment with two fresh 1500ml. portions of denatured ethanol. After drying in an evaporating dish for forty-eight hours in a circulating air oven at 60°, the copolymer was analyzed in duplicate for nitrogen by the micro-Dumas method. Analytical data and conversion values are summarized in Table I.

Surface areas of cottons differing in variety and maturity, and cottons that had been subj ected t o various physical and chemical t reat m ents wer e meas ured before and after swelling. Swollen cottons were prepared by immersing air-dried cot tons in wat er a t roo m t emperature for 24 houl's, displacing the water wi th m etha nol and t h e m ethanol wi th p entane, and fin a lly drying the fibers. Surface areas were calculated from the quantity of nitrogen ad sorbed a t -195.8° C.The specific surfaces of unswollen fib ers were less t han 1 square m eter p er gram ; t hose of the swollen fib ers ranged fr om 4 to 148 quare m eters p er gram . Purificat ion and m erceri zation produ ced in creases in th e surface ava ilable a fte r s welling; m eth ylenat ion produced a d ecrease; eth ylamine t rea t ment had no effect. In t he early stages of m ethanolysis, a d ecrease in t he surface availa ble after swelling occUl'red ; in th e later stages, a n incr ease.Although urface area m easuremen ts were p ro bably i n no instance made on completely swollcn fiber, the procedure employed is believed to be useful in evaluat ing th e effects of vari ous t reatments 011 cotto n and other cellulose fibers.

Kinetics of the Carbonic Acid Dehydration 809 counted for by the repulsion of both H+ and CIO4ions which is experimentally observed at the cathodic branch of the electrocapillary curve.On concluding, one may note that for Hg in acid solutions the slow proton discharge is more probable than the slow electrochemical desorption.

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