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),

METAl. S,\IfI'S AND l'OIA•MER-CONTAINlN( HAIR 183 and methacrylic acid (lXlA)--were separately polymcrized in hair fibers by the procedure described in the experimental section of this report. The fibers were calibrated to 20% extension in water, treated with 0.131 mereuric acetate at room temperature for •/._, hour and re-extended to 20% of their length in water. Data describing the resnltant changes in the W• of the fibers are summarized in Table IV. Table IV Effect of Monomer Functionality •r/ Change in W• from Monomcr Av % Polymer in Fibers Polymerized State" DEM 14 +16 AN 12 +48 EGM 21 +23 MA 16 Results are all significant beyond the o• = 0.05 level. Large increases in the wet load extension properties of the fibers con- raining PDEM, PAN, and PEGM resulted after treatment with mereuric acetate however, relatively small effects were produced by the same treatment to the carboxylic acid-containing hair (PMA). Since mercury(II) is an excellent electron acceptor and has been shown to coordinate with various kinds of donor groups (12), reaction of mercuric acetate with polymer-containing keratins possessing donor •oups such as polytertiary mnine, polynitrile, or polyhydroxy and/or those donor groups normally present in the hair structure, e.g., amino, guanidino, hydroxyl, carboxyl, and mercaptan (free or formed [rom disulfide). should occur readily. Therefore, coordination reactions are believed to be responsible for the observed changes in the tensile properties of the polymer-containing fibers described in Table IV. The reaction of mereuric acetate with hair fibers containing PDEM has been studied more extensively than the reaction of this same reagent with the other polymer-containing fibers and additional results from these studies are described below. Elleel o[ the Polymerization Reaction o• the Tensile Properties o[ Hair Since the reductive-polymerization procedure employed in these studies consists of a two-step process, the first step being reduction and the second step being actual polymerization, the possibility of altering the mechanical properties by reduction as well as alteration due to the