2006 TRI/PRINCETON CONFERENCE 1000 - -------------------� c.. 100 u Excess polyanions Excess polycations ----· ------- 465 - � • PVM/MA 0.2% r/J 0 u .!? 10 1 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 Unit mole ratio of Polyquaternium-28 to PVMIMA Copolymer Figure 10. Dependence of viscosity on unit mole ratio cationic to anionic groups. stoichiometric charge ratio of one to one where the stoichiometric equivalence of cationic and anionic charges are the same. This indicated a maximum in the amount of microgels formed since these are discrete particles that are dispersed in solution. Polymer ratios deviating away from the one to one stoichiometric equivalence would contain polymer not associated in a microgel and would increase the viscosity of the solution. The lower viscosity evident for the 1: 1 ratio was due to the hydrodynamic volume of the complexed chains being smaller than when free un-complexed polymers are present in solution at other charge ratios. This charge-charge interaction contributes to the compact nature of the microgel structure of the complex and exemplified the stoichiometric interaction of the two polymers. It was determined that the complex chosen to repair split ends has a cationic to anionic charge ratio of precisely 1.14. MENDING TEST RESULTS OF MICROGEL COMPOSITION A screening study showed the efficacy of the polyelectrolyte complex in split end mending durability. The control systems were based on the component polymers of the complex used alone and a clear 1: 1 mixture of the two polymers where there are no discrete microgels present. All polymer and polymer combinations were kept constant at a total of 2.00% active. This screening study consisted of measuring twenty tagged fibers for each formulation instead of the usual one hundred and was based on complete mending as observed with a magnifying glass. Test results showed that the complex had increased durability of mending over the control formulations. Test results are in Table III. When the complex was used alone at 2.00% active in a one hundred fiber study it mended 92 out of 100 fibers after treatment and before combing. After combing the tress twenty times 68 fibers remained mended. When the 2.00% active complex was formulated into a simple lotion formula thickened with Xanthan Gum approximately

466 JOURNAL OF COSMETIC SCIENCE Table III Screening Experiment Showing Efficacy of Complex Over Systems Used as Controls % Mending % Mending after after Durability Formula type treatment combing index 2.00% neutralized PVM/MA copolymer 90 15 0.17 2.00% Polyquaternium-28 75 40 0.53 2% Complex 0.20 neutralized PVM/MA copolymer and 1.80 polyquaternium-28 90 75 0.83 1.00% neutralized PVM/MA copolymer plus 1.00% polyquaternium-28 85 20 0.24 the same results were obtained. This provided evidence for two things. First, that the results were reproducible giving validity to the test method. Second, the complex could be formulated into a system without loss of efficacy. Results are portrayed in Figure 11. In both cases the durability indices of the mending after combing was over 70%. As mentioned in the procedure there are 100 fibers tested for each treatment, twenty fibers tagged on one tress times five tresses. The data illustrated in Figure 12 shows the variability of mending for each tress for both before and after combing on the full formulation. The average and standard deviation of the mending results after combing of the five tresses is 67.6 ± 12.6%. Comparing this mending data to a control formula containing just the thickening agent as can be seen in Figure 13 shows the significance of the difference. From this it can be concluded that the complex is responsible for the high mending scores. 100 80 � 60 .5 "'C C 40 20 0 Stereomicroscopy Results of Mending Efficacy Primary Splits, Complete+partial Mending -.-------7"'n"'l'"""7----� Complex alone, 149A before com bing §I In a full formula, 61 B 68 67.6 after combing Figure 11. Total percent mending of complex alone and in a framework formula both before and after combing.