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

184 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS incorporation of poly•ner within the fibers exists. For esti•nating deg- radation resulting from each of these reactions 12-in. fibers were cut into two 6-in. sections, weighed, and mounted on cellulose acetate tabs 4 in. apart. Subsequent to calibration to 20% extension, the fibers were relaxed in water, reduced, and treated with DEM according to the procedure described in the experimental section. These fibers were then cut from the tabs and reweighed to determine the amount of poly- mer. The range of polymer in the fibers was from 5 to 11%. These same fibers were remounted on cellulose acetate tabs 2 in. apart and restretched to 20% at one-half the previous extension rate. Assuming the fibers to be uniform and unaltered by the treatment, the two sets of load extension curves should be equivalent. A set of control fibers was treated similarly with all reagents except monomer in the redtic- five-polymerization procedure. The results from this experiment are summarized in Table V. Table V Effect of Polymerization on the Tensile Properties _ Reduced-Unpolylnerized Reduced-Polymerized Parameter Controls (% Change) b Fibers (% Change)•' _ W• --14 --13 Eg --15 --14 F.,0 -- 14 -- 11 • Work recovered on 20% extension. b Results are all significant beyond the a -- 0.05 level. The data indicate that the wet extension properties of hair fibers treated under the conditions of reductive-polymerization, as used in this work, are decreased from 10 to 1,•c•o, and that the reduction step is primarily responsible for the observed decreases. In addition, the amount of PDEM incorporated into the fibers, within the limits t,f the•e experiments, de, es not appreciably affect the wet load extension properties. E[Jccl of Ti.tc o• the Reaclio• of Mercttric Acetate with PDEM-Conlai•i•tg Hair Fibers l tair fibers containing between 9.6 and 10.6% PDEM were treated with 0.13I mercnric acetate in 0.1N acetic acid at different ti•ne intervals at room temperature (24øC). Figure 1 illustrates graphically the change in the W• (reaction of •nercuric acetate with the fibers) with time. •Fhis reaction is rapid and for all intents and purposes is co•npleted