Glycolic Acid No Longer Just for Skin—Changing the Internal Properties of Hair

Nov 1, 2013 | Contact Author | By: Trefor A. Evans, TA Evans LLC; and Jennifer M. Altland, Robert Burch and Jeff Horsager, E.I. duPont de Nemours and Company
Your message has been sent.
(click to close)
Contact the Author
Save
This item has been saved to your library.
View My Library
(click to close)
Save to My Library
Title: Glycolic Acid No Longer Just for Skin—Changing the Internal Properties of Hair
glycolic acidx hair fiberx penetrationx tensile propertiesx
  • Article
  • Media
  • Keywords/Abstract
  • Related Material

Keywords: glycolic acid | hair fiber | penetration | tensile properties

Abstract: As the smallest alpha hydroxy acid (AHA), glycolic acid is frequently found in anti-aging products due to its ability to penetrate skin and reduce wrinkles, acne scarring, hyperpigmentation and other conditions. This work describes how it is also able to penetrate into hair and, in doing so, bring about a number of changes to the internal fiber properties.

View citation for this article

TA Evans, JM Altland, R Burch and J Horsager, Glycolic Acid No Longer Just for Skin—Changing the Internal Properties of Hair, Cosm & Toil 128(11) 816 (2013)

Market Data

  • Consumers are looking toward hair for anti-aging benefits.
  • Anti-aging hair care products address concerns such as thinning, coloring, breakage and drying, with emphasis on particular ingredients that target specific hair issues.
  • Although trends in anti-aging hair care are currently focused primarily in North America and Europe, hair care brands are seeing opportunities globally, including emerging markets.
view full article

Excerpt Only This is a shortened version or summary of the article you requested. To view the complete article, please log in or create an account. Registration is Free!

Conventional daily use hair care products are predominantly based on relatively large molecules such as surfactants, polymers and oils. However, the size of these molecules suggests a limited ability for penetration, and their efficacy is therefore restricted solely to the hair surface. In short, conditioning and styling ingredients are deposited at the surface and subsequently removed by the surfactants in shampoos. However, there may be a next generation of products that can be developed and will manipulate the internal properties of hair—and presumably, these products must revolve around smaller molecules that are better able to penetrate.

This article describes results from three test methods that measure properties relating specifically to the internal structure of hair. In each case, the treatment of hair with glycolic acid brings about significant changes in the bulk properties of hair. Note that unless otherwise specified, the work described here was performed using 5% solutions of a commercially-available cosmetic grade glycolic acid.

Excerpt Only This is a shortened version or summary of the article you requested. To view the complete article, please log in or create an account. Registration is Free!

 

Close

Figure 1. Structure of glycolic acid

Figure 1. Structure of glycolic acid

In each case, the treatment of hair with glycolic acid (see Figure 1) brings about significant changes in the bulk properties of hair.

Figure 2. The decrease in dry state modulus for bleached hair upon treatment with 5% glycolic acid

Figure 2. The decrease in dry state modulus for bleached hair upon treatment with 5% glycolic acid

Figure 2 shows that treatment with glycolic acid significantly decreased the Young’s modulus of hair.

Figure 3. Adsorption and desorption isotherms for hair treated with glycolic acid versus untreated control

Figure 3. Adsorption and desorption isotherms for hair treated with glycolic acid versus untreated control

Figure 3 shows how treatment with glycolic acid produced a significant reduction in the water content of hair.

Figure 4. Results from a typical DSC experiment to evaluate the thermal denaturation temperature of wet hair

Figure 4. Results from a typical DSC experiment to evaluate the thermal denaturation temperature of wet hair

Under these conditions, healthy hair yields a denaturing temperature of around 155°C (see Figure 4), but this value will decrease as the hair becomes more damaged.

Figure 5. The penetration of glycolic acid inside of hair fibers (from L): bleached control, bleached treated at 1% (1 x 1 min) and bleached treated at 1% (5 x 1 min)

Figure 5. The penetration of glycolic acid inside of hair fibers (from L): bleached control, bleached treated at 1% (1 x 1 min) and bleached treated at 1% (5 x 1 min)

The resulting images demonstrate the penetration of glycolic acid inside the hair fibers (see Figure 5).

Footnotes (CT1311 Evans)

a DuPont GlyPure (INCI: Glycolic Acid) is a product of E.I. duPont de Nemours and Company.
b The tests described utilized a Dia-stron MTT 675, manufactured by Dia-stron Ltd.
c The DVS-Intrinsic system used for this study is manufactured by Surface Measurement Systems.
d [14C]-Glycolic Acid from American Radiolabeled Chemicals was used for this study.

Next image >