i\IE•I'AL SAI.TS AND POLYMER-C()NTAINING HAIR 181 limit (E,,), and the force to 20% extension (F..,0). The statistical results were calculated using the method of paired differences. RF. SUI I'S AND DISCUSSION Reactions of Metal Salts with Polymer-Containing Keratin Fibers In the initial experiments, polycarboxylic acid-containing hair [poly- (methacrylic acid), (PMA)] and polyalcohol-containing hair [poly(ethyl- ene glycol monomethacrylate), (PEGM)] were reacted with salts of mag- nesium and calcium. For the PMA-containing fibers the possibility for salt link formation existed as well as the possibility for coordination. Results from these experiments (Table I) show no encouraging positive changes in the work of elongation (W•) [or these treatments. The fail- ure of these treatments to produce increases in the load extension prop- erties of the fibers is presumably due to a [ailnre to complex, which is probably a result of the poor complexing capabilities of these two metals (11). Therefore, stronger complexing metals were selected for examina- tion. Salt Table I Reaction of Grafted Keratin Fibers with Calcium and Magnesium Significant Beyond % Change •x = 0.05 Polymer in Fibers pH W•, Level CaC1.0 PMA (19.8%) 10 --5.5 Yes Ca(NOa).2 PMA (19.8%) 2 -- 1.5 Yes MgCi• PEGM (21%) 10 -3-1.8 No CaCI,, PEGM (21%) 7 +0.12 No CaC1.0 PEGM (21%) 10 q-1.4 Yes Several transition metal salts, including salts of manganese(II), iron(II), cobalt(II), nickel(II), copper(II), mercury(II), and zinc(II) were each reacted with hair fibers containing PMA. The results from these experiments are summarized in Table II. The treatments with nickelous chloride, cuprio acetate, and mereuric acetate were all en- couraging in producing increases in the work to 20% extension. Some of these same metals were also examined for their reaction with hair containing [poly(N,N-dimethylaminoethyl methacrylate), (PDEM)], Table III. For the tertiary amine-containing hair, these data show a positive increase in the W• only for the mereuric acetate treatment. This increase is 16%. These restilts may be interpreted in terms of a

182 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Reactions of Metal Salts with PMA-Containing Hair Salv' pH % Change Significant Beyond o• = 0.05 Level MnSO4 2 4-1.6 No FeSO4 2 4-0.5 No COC12 7 --0.6 No NiCI,, 7 -3-4.9 Yes Cu(OAc),, 7 4-4.7 Yes Hg(OAc)2 2 4-4.1 Yes Zn(OAc)2 3.5 --3.9 Yes a Salt concentrations are all 0.1M and treatment times 2-5 hr. between 16.2 and 19.8% PMA. Table III The hair fibers contained Reactions of Metal Salts with PDEM-Containing Hair Metal Metal Concn(M) '• pH b CdSO4 Pb(OAc)2 AgCLO4 Zr (OAc)4 Cu(OAc)s 0 1 01 01 0 29 0 27 Change in Ws from Polymerized State • 2.0 -5.5 3.5 -5.7 3.0 -14 7 -3.4 7 --1.3 Hg(OAc),, 0 1 (0.1N HOAc) 4-16 [--1.4]a Zn(OAc)2 0 1 3.5 --5.9 ____ a Fibers in the above experiments contained on an average 14c• PDEM and all reaction were carried to •/• hr at room temperature. •, •here pH adjustments were made glacial acetic acid was used. •' Results are all significant beyond the o• = 0.05 level. a Estimated change from the untreated state assuming a 15• • lowering due to reduction and polymerization. rebuilding (crosslinking) mechanism or in terms ot/ a reduction in the saturation water content of the fibers by the attachment of hydrophobic residues. In either case, the gzeater effect for the tertiary amine (PDEM)-containing hair as compared to the carboxylic acid-containing hair probably results from a more rapid penetration of the reagent into the fibers under the reaction conditions and a gTeater propensity for mercury to coordinate with nitrogen than with oxygen (12). As a result of these experiments mereuric acetate was selected for further study. Effect of Polymer Functionality on Mercuric Acetate Reaction Four different vinyl mononmrs--dimethylaminoethyl methacrylate (DEM), acrylonitrile (AN), ethylene glycol •nonomethacrylate (EGM),