J. Cosmet. Sci., 62, 149–160 (March/April 2011) 149 Characterization of hair styling formulations targeted to specifi c multicultural needs ANDREA C. KEENAN, ROBERT F. ANTRIM, and TERRI POWELL, The Dow Chemical Company, 727 Norristown Rd, Spring House PA 19477. Synopsis The ethnic hair care market is large and diverse, with many unmet needs, especially when the defi nition of ethnic varies as much as the hair does. By examining the variety of hair care raw materials now available, we designed hair styling formulations for targeted benefi ts such as anti-frizz, conditioning, style control, humid- ity resistance, UV protection and color loss protection. We have characterized three distinctive hair styling formulations targeted to specifi c multicultural needs. This has been completed by using standard personal care laboratory evaluations including the Diastron Limited TM Miniature Tensile Tester for stiffness, the Bossa Nova Technologies TM Shine Instrument, high-humidity curl control, UV exposure, and expert panel evalua- tions the results were substantiated using current state-of-the-art analytical tools, including atomic force microscopy and scanning electron microscopy. Results demonstrate that a varied product portfolio is required for such a diverse market segment. Styling products ranging from alcoholic sprays, leave on styling creams or gels and styling curl activators offer performance attributes that can be utilized on a variety of hair types such as Asian, African, Caucasian and Brazilian. INTRODUCTION Film forming polymers and cationic conditioning agents offer improved luster, style/ humidity control, anti frizz and conditioned feel on many types of multicultural hair, including: African, Asian, Caucasian, and Brazilian hair. African hair is most diffi cult to control because the hair shaft is shaped like a fl attened oval and will self-curl or coil on itself. Brazilian hair is a mixture of hair types that is wavy in nature and refl ects the di- verse ethnicity of much of the population in the Americas. Asian hair is cylindrical and the most challenging to curl. See Figures 1a, b, c, and d. Not only are there variations of hair based on ethnicity, but other hair variations exist such as, along a single strand, from strand to strand ,and the hair experience: UV exposure, color dyeing, bleaching, perming, relaxing, heat tools, and mechanical damage. Formulating for a variety of enhanced attributes on a variety of ethnic hair types can be achieved by the use of acrylates/hydroxyesters acrylates copolymer for enhanced shine, fl aking resistance, humidity and style control zinc oxide and simmondsia chinensis (jojoba) seed oil and glyceryl stearate and polyhydroxystearic acid (to be referred to as zinc oxide and jojoba oil) for color protection, feel and anti-frizz control polyquaternium-10

JOURNAL OF COSMETIC SCIENCE 150 and polyquaternium-67 for ease of combing, feel, and manageability acrylates/steareth-20 methacrylate crosspolymer for rheological properties, enhanced style control and high hu- midity resistance. Treatment of African or Brazilian hair tresses as well as Caucasian or Asian hair types with styling treatments based on these products provide excellent anti- frizz control compared to silicones and maintain overall control under humid conditions. Intensive testing indicates, depending on the hair type, that changes in the styling ben- efi ts and attributes can be delivered for a natural, not coated feel with different formula- tions. Characterization of these prototype formulations was completed by using a variety of methods—from expert panelists, curl stiffness, UV damage, color loss protection, and humidity testing to highly sophisticated analytical tools including SEM morphology and elemental mapping and AFM. EXPERIMENTAL METHODS Our experiments involve the use of standard personal care methods as well as state of the art analytical tools. These are described in this section. DIASTRON CYCLIC COMPRESSION: STIFFNESS RETENTION Pretreatment: The hair tresses (European Brown Virgin Hair, obtained from • International Hair Importers, New York) prior to curling were on the average 8 inches long and weighed 3.5±0.1 grams. They were washed in mild shampoo before using and curled wet onto a 22 millimeter (mm) × 70 mm curler and held in place with a bobby pin. The curled tresses were allowed to dry on the lab bench overnight. The curled tresses were uniformly sprayed twice in the front and twice on the back from • a distance of 20.3 centimeters (cm) with the hair spray formulation. The spray device dispensed 190 μl (micro liters) of formulation with each compression. The spray device product was “Euromist ClassicTM” and was manufactured by SeaquistPerfect, Cary, IL. The curled, treated tresses were dried for 1 hour in a controlled environment at 22.5°C and 55% relative humidity. The curler was removed carefully without uncurling the tress. The curled tress was placed in the miniature tensile tester, model MTT160 instrument (Diastron Limited, Unit 9 Focus 303 Business Centre, Andover, Hampshire SP10 5NY UK, or 390 Reed Road, Broomall, PA 19008, USA) and the work to compress the curl to 50% of its initial diameter was measured. The compression was repeated fi ve Figure 1. (a) African oval-fl at shape moderate diameter. (b) Caucasian semi-oval elliptical fi ne/moderate diameter. (c) Latin semi-oval elliptical fi ne/moderate diameter. (d) Asian round to circular large diameter.