246 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS TABLE 7B--CoMPARISON OF COMPATIBILITY OF GLYCOL-SILOXANE COPOLYMERS AND 200 AND 555 FLUIDS WITH VARIOUS MATERIALS* Dow Com•g Ethylene glycol Polyethylene glycol 400 Dow Corning 200 Fluid Me:S•O Content Med. I'll Low Med. Hi SSS Fluid 350 cl Steoryl alcohol C C C C C C i Isopropyl myristate C C i i C C (• ß Glyceryl monastearate C C C C C C i Diglycol stearate C C C C C C • Oleic acid C C C C C C i Stearic acid C C C C C C i 200 Fluid, I00 cs , i • • • C C 55• Fluid f i i i C C i Tested at room temperature as o m•x made up of 1 part sd•cone to lO parts material hsted C----compatible •--mcompahble Ethylene and polyethylene glycol copolymers have been prepared at various dimethylsiloxane concentrations. These copolymers were prepared so that the ratio of dimethylsiloxane to glycol varied from a low to a high value. In some cases ethylene glycol was used as the substituent, while in other polymers, a polyethylene glycol of about 10 ethylene oxide units was substituted. A summary of the typical properties of these copolymers is presented in Table 6. In general, the glycol-siloxane copolymers are clear, water-white liquids with a slightly oily feel. The polyethylene glycol copolymers increase in viscosity as the dimethylsiloxane content increases, while the ethylene glycol derivatives remain relatively constant. The refrac- tive index of these copolymers lies in an intermediate position between that of the pure glycol and the dimethylpolysiloxane fluids. These copolymers have low surface tensions and spread rather easily. The compatibilities of the glycol-siloxane copolymers are markedly differ- ent from what is normally expected of silicones. Table 7 portrays these data. The polyethylene glycol derivatives are generally compatible with 70 per cent and 90 per cent isopropanol 95 per cent ethanol, stearyl alcohol, esters and fatty acids. On the other hand, they are generally incompatible with beeswax, mineral oil, vegetable oil and water. As the copolymers become more silicone in character, compatibility with isopropyl myristate improves, while compatibility with paraffin, ethylene glycol, propylene glycol and glycerine is impaired. The ethylene glycol copolymers are similar to the polyethylene glycol copolymers in solubility. However, in contrast to the polyethylene glycol copolymers, the ethylene glycol copolymers are generally compatible

NEW SILICONES FOR THE COSMETIC INDUSTRY 247 • eo ,( 4o _ Cell = Standord Path Lenth: 1 cm /' • / low Me•SiO content medium MG•SiO •ntent ./ •- • high M•SiO cantent / // / 220 240 260 280 300 320 340 360 380 400 420 V•AVE LENGTH, rmlhrnicrons Figure 5.--Light transmission of polyethylene glycol-siloxane copolymers. with isopropyl myristate and animal fats and waxes, but are incompatible with the hydrocarbon oils and waxes. Light transmission data are presented in Fig. $ for the polyethylene glycol-siloxane copolymers. The absorption characteristics of these copolymers improve slightly as the siloxane portion of the copolymer increases. The glycoLsiloxane copolymers may find application where limited silicone characteristics are desired, but where alcohol solubility and ease of removal are prime requisites. SUMMARY A few of the many types of silicones we have synthesized in our research laboratories have been presented. These materials are, for the most part, available only in research quantities. You have seen that a copolymer of an organo-silicone with organic substituents can be made to possess a host of unusual properties. This is accomplished, however, at some sacrifice to the properties normally associated with silicones. In other words, as the organic portion of the molecule is increased the effect of the siloxane group is diluted so that the molecule approaches the characteristics of the organic substituent. The three types of organo-silicones which have been described in terms of their chemical reactivity and physical properties are: 1. Salicyloxymethyl dimethylsilyl end-blocked fluids 2. Fatty alcohol esters of dimethylpolysiloxane 3. Glycol esters of dimethylpolysiloxane