Recently in Published Literature Category

Here's a paper I helped author back in 1998 regarding recent advances in the treatment of excessively curly hair. While I know that 1998 was ten years ago, the paper contains good content regarding the history of relaxers as well as how modern-day relaxers work.

Recent Advances in Treating Excessively Curly Hair

Cationic polyamines and starch hydrolysates

Ali N. Syed, Hasan Ayoub and Anna Kuhajda

Avlon Industries Inc., Bedford Park, IL USA

In literature, innovation is defined as the initiation or adoption of new products, processes or ideas by organizations. Such innovations have taken place in the care of excessively curly hair. These developments did not catch the attention of the masses in the US because a relatively small segment of the population possesses curly hair. On a worldwide scale, however, the number becomes larger when we include individuals from Africa, the Caribbean, South America, the Middle East, Asia and North America, According to some estimates, this segment with excessively curly hair has grown to equal a $1.5 billion (US) industry.

A History

Before discussing the history of the curly hair-care industry, it is necessary to understand the nature of excessively curly hair. Compared to straight hair, excessively curly hair is like a twisted ribbon in terms of its physical configuration. It is difficult to comb both in its wet and dry states, is hard to style and is highly unmanageable. More fragile than straight hair, excessively curly hair breaks more readily upon stretching, excessive combing and brushing. Thus, excessively curly hair requires special handling and specially formulated products that are different from Caucasian hair-care formulas.

In 2000, I co-authored an article for C&T magazine regarding the scalp irritation potential of lye and no-lye relaxers. The article includes our findings from a study based on comfort/discomfort evaluations from salon patrons.

Compared to Caucasian hair, African-American hair is extremely curly and it's physical configuration resembles a twisted ribbon. It is highly unmanageable. very difficult to comb-both wet and dry-and hard to style. More fragile than Caucasian hair, this excessively curly hair breaks more easily when stretched or vigorously brushed and combed. Thus, African-American hair requires both special handling and hair-care products that are differently formulated than those for Caucasian hair.

Madam C. J. Walker: A Beauty Product Pioneer

Madam C. J. Walker was an early 20th century beauty product pioneer. She was born under the name Sarah Breedlove to ex-slaves in 1867. In her early life, she worked in both the cotton fields and the kitchen. In 1905, after marrying newspaper sales agent Charles Joseph Walker, she adopted his name and developed expertise in manufacturing hair goods and preparations.

Walker soon launched her own business, designing cosmetics and hair-care products for black women. From this business she became one of the nation's first female millionaires. Using her success for the good of others, she earned a reputation as a philanthropist to African-American institutions such as the NAACP, Tuskegee Institute and Bethune-Cookman College. She died in 1919.

In 1998, the US Postal Service issued a stamp commemorating her achievement as an African-American businesswoman and philanthropist. The image on the stamp is from a circa 1914 photo that was used extensively by Walker's company for publicity purposes, in advertising, and on its products.

The Development of Relaxers

In the early 1900s, an African-American domestic worker, later known as Madam C. J. Walker, invented pomade using a combination of oils (see sidebar). This pomade revolutionized the hairstyling practices of African-American women and made excessively curly hair softer, shinier and somewhat easier to comb. However, the pomade did not straighten the hair. African-American women still could not achieve styles like those worn by Caucasian women.

Here's a study that I helped author in 1995 regarding the physical properties of African American hair and how it differs from Caucasian hair. Enjoy.

Scientific innovations in chemical treatments that alter the texture of African-American hair, as well as a plethora of style trends, have spurred phenomenal growth in this
segment of the hair-care market throughout the past three decades. The level of research & development by manufacturers in the area of product formulation has steadily elevated; yet, a great deal remains to be learned about the unique physical properties of African American hair. Compared to the vast body of research regarding Caucasian hair, the study of African-American hair is at best limited.

A Review of Research

In published studies, J. Menkart et al, Epps et al and Kamath et al reveal that some important research has indeed been conducted on the physical properties of highly curly hair. The efforts of these researchers and the results of their studies serve as a starting point for the further study of African-American hair. Other general observations about hair, such as those pertaining to static charge (Jachowicz and C.R. Robbins) and theories about moisture content, serve as a springboard for advancing the study of African American hair.

Shape: Menkart and Wolfram report that African-American hair has a physical shape resembling a twisted oval rod, whereas Caucasian hair is more cylindrical. They found evidence of this when they made elliptic comparisons or hair cross-sections. Using a formula in which the minor axis is divided by the major axis, Menkart and Wolfram
determined that African-American hair has a ellipticity index of 0.56 and Caucasian hair has an index or 0.7.1. The tensile-strength data gathered during this research shows that the breaking stress of African·American hair (1.24 g/denier, a unit of fineness equal to the fineness of a yarn weighing 0.05g for each 450m of length or 19 for each 9000m.) is less than that of Caucasian hair (1.41 g/denier). The yield stress for African-American hair, however, is slightly higher (0.46 g/denier VS 0.42 g/denier).

Kamath and Hornby studied the fractographic behavior of African-American hair to view both major and minor rods at low levels of extension. They examined the ellipticity of
hair fibers and reported ellipticity indices of 1.89±0.083 and 1.0 to 1.4 for African-American and Caucasian hair, respectively. In this study, the ellipticity index was calculated by dividing the major axis by the minor axis, which is the reverse of the formula used by Menkart and Wolfram.

Combability: Epps and Wolfram conducted combing comparisons between African-American and Caucasian hair using combability techniques used by Garcia and Diaz. Garcia and Diaz report that African-American hair, due to its curliness, is much more difficult to comb than Caucasian hair. It was also determined that African-American hair is easier to comb wet than dry.

Using a scanning electron microscope at a magnification of about 300X, Kamath and Hornby also observed that African American hair display frequent twists with random reversals in direction and pronounced flattening. During fractographic study, the break stress of African-American hair was reported to be (0.123 ± 0.016) 10^9 N/m^2 when dry (65% relative humidity [RH]) and (0.119 ± 0.010) 10^9 N/m^2 when wet. The breaking elongation for wet and dry (65% RH) fibers was found to be 44% ±3% and 27% ± 5%, respectively.

Here's a study me and my colleague authored in November 2002 exploring the relationship between porosity and tensile strength of hair fibers.

Over the years, many individual studies have been conducted regarding the extent of damage imparted to hair. These studies deal with the damaging effects of various chemical processes such as permanent waves, permanent colors and hair bleaches.

The most commonly employed method to quantify this damage is the measurement of change in tensile properties of the hair. This method takes two to three days in the preparation of samples of hair fibers. It also requires a minimum of 30 to 40 fibers for statistical analysis. Therefore, there is a need for other simpler methods that are equally valid and less time-consuming.

One such method could be the determination of hair porosity or water uptake of hair fibers as described by Valko et al and by Menkart et al. However, to the best of our knowledge, no study so far has correlated the tensile strength method with the water uptake (swelling/porosity) method following chemical treatments such as permanent
waves, permanent colors, hair bleach, and permanent hair relaxers.

Therefore, we have conducted a study whose purpose was to validate the porosity method against the tensile strength method. Another purpose of this study was to use these two methods to compare the magnitude of hair damage between permanent waving, permanent coloring, hair bleaching, and permanent straightening processes. Finally, this study ranked the various chemical processes in terms of their hair damage potential. We believe this is the first comparative damage ranking for various chemical processes in the hair care field.

Swelling or Porosity of Hair

Professionals who are involved in the art of styling hair define the porosity of hair as the capacity of hair%2