Go beyond conditioning: COSSMA

Photo: Dmytro Zinkevych/Shutterstock.com

Natural ingredients – this is one very important demand of more and more customers. An alternative in hair care could be a biodegradable polymer based on cellulose technology.

Within the past few years, a trend towards natural, organic, or sustainable products has increased significantly in the hair care markets. According to a report by Grand View Research in 20201, the natural hair care product market size is expected to increase at a compound annual growth rate of 4.7% from 2020-2027. Consumers are willing to spend more for products with “natural” or “organic” claims, but they will not sacrifice product performance and efficacy. This has become a challenge for the beauty industry to identify new natural ingredients that address the consumers’ needs while still maintaining high performance levels.

A new cationic cellulosic polymer2, was recently developed as a natural alternative for hair care applications. This is a versatile, bio-derived and inherent primary biodegradable (according to OECD test(s) guidelines) technology. It has a cellulosic backbone, with 48% bio-derived content derived from non-GMO and PEFC certified wood pulp. It contains a cationic functionality, which increases the polymer deposition onto the surface of the hair fibres. This polymer is dispersible in water and can be incorporated into the formulation directly, without emulsification.

While the polymer is versatile enough to be used in various hair formulation formats, including rinse-off and leave on products, the most pronounced benefits have been identified in rinse-off conditioner. This article describes the new cationic cellulosic polymer as a stand-alone conditioning agent in rinse-off conditioner. The results were compared against traditional amino silicone and cationic cellulose polymers. A summary of each polymer is shown in table 1.

The polymer was first formulated in the below rinse-off conditioner chassis (table 2) at 0.3% and compared to a control rinse-off conditioner without silicone or “traditional” cationic polymer. Other cationic cellulosic polymers3 and silicones were formulated in the same chassis at respectively 0.3% and 1% active.

Then, slightly bleached Caucasian hair was used for testing the rinse-off conditioners. Three tresses were used for each treatment. Each tress was washed with 9% SLS solution prior to each experiment, treated with 0.4 g/g of hair with rinse-off conditioner and air dried at room temperature prior to the analyses.

Dry and wet combing performances were evaluated using Diastron MTT175 equipment (figure 1) and Instron tensile tester (figure 2). Combing performances of the polymer on dry and wet hair were compared to silicones (figure 1) and other cationic polymers (figure 2).

The new cationic cellulosic polymer shows low average combing load on both dry and wet hair translating into good conditioning performances on damaged hair, achieving close performances to aminosilicones4 with three times less active level of product. When compared to commercial cationic cellulose polymers5, it performs significantly better in both dry and wet combing.

figure 1: Comparison of dry/wet combing performances with silicones

figure 2: Comparison of dry/wet combing performances with cationic polymers

Sensory evaluation

Performed on 20 panellists, it showed that hair treated with the new cationic cellulosic polymer is smoother, more slippery, more aligned, less tangled, and easier to comb than tresses treated with amodimethicone and cationic polymer benchmark (figure 3).

Everyday brushing and combing can contribute to significant hair breakage. During brushing and combing, a combination of bending, torsion, and interfiber friction can result in localised stresses, which lead to physical damage, wear by abrasion, and eventually hair breakage. To simulate how consumers assess the strength of their hair, hair tresses were repeatedly combed 10,000 times at a speed of 20 cycles/minute (80 comb stokes/tress/minute), followed by a measurement of hair loss.

As anticipated, an increased number of broken hair fibres were generated with repeated combing. The most damaged part was found in the tip area where the hair is the oldest, most tangled, and has the highest density of catastrophic flaws. The breakage was drastically reduced when the hair was treated with a modified amodimethicone6 with greater than 90% breakage reduction compared to the control, 66% compared to a conditioning agent7 and 30% compared to traditional polyquaternium-108. These results show that the new cationic cellulosic polymer provides considerable protection against breakage caused by repeated grooming. This is likely due to its ability to provide a higher surface lubrication, which sub-sequently reduces grooming forces and prevents damage caused by mechanical stress.

Restoration of hair hydrophobicity is key to make hair look healthy. Hydrophobicity of hair has been assessed by measuring the contact angle (initially and after around two minutes) of a 30µl water droplet deposited on top of hair treated with a rinse-off conditioner containing either the new cationic cellulosic polymer or silicone or other cationic cellulosic polymer or none of the latter (control). Figure 4 shows that hair treated with the new cationic cellulosic polymer retains a high degree of hydrophobicity translating into more hydrophobic and therefore healthier hair.

figure 3: Sensory evaluation on dry hair. Statistics: Significant difference at *** ≥99.9%; ** ≥99%; * ≥95%; Blue*: Statistical difference between Ucare Extreme Polymer and Dowsil 2-8566 Amino Fluid;Red*: Statistical difference between Ucare Extreme Polymer and Ucare JR-30M Polymer

Practical test

The ultimate test of performance is consumer acceptance. To assess the product under real use by consumers, a salon test was run by laboratory Kosmoscience. The study compared the performances of a rinse-off conditioner containing the new cationic cellulosic polymer at 0.3% to the same formula with an amodimethicone9 at 1% active.

Thirty research subjects (mean age: 33 ± 7 years) were part of this study and were divided into two groups according to the hair characteristics: Group A (straight hair) and Group B (wavy and curly hair).

A standard shampoo was first applied to standardise the hair washing and then the investigational products were applied in a standardised way on a half head. The subjective analysis for perceived efficacy was performed by the hairdresser after the application of the rinse-off conditioners on wet hair and dry hair and by the research subjects after application on wet hair and dry hair immediately after the application and after eight hours of application of the investigational products.

The subjective analysis for perceived efficacy was performed through the application of a step-specific questionnaire answered by the hairdresser and by the research participants, considering a hedonic scale of five points (1 – strongly disagree to 5 – totally agree).

Hairdresser did not find any statistically significant difference on dry hair between the two tested rinse-off conditioners regardless of the hair type (straight or curly/wavy). For straight wet hair, hairdresser found that rinse-off conditioner with the new cationic cellulosic polymer has the same performance as silicone conditioner except for smoothness, conditioning, and natural appearance where it is less performing. For wavy/curly wet hair, it showed same performance as silicone conditioner but with less natural appearance.

From the consumer perspective, research subjects of group B (wavy/curly hair) did not find any statistically significant difference between the products whatever the hair stage (dry or wet). For research subjects with straight hair (group A), rinse-off conditioner with the new cationic cellulosic polymer showed the same efficacy as silicone conditioner with smoother feel on wet hair and better conditioning and film forming effect on dry hair. After eight hours from application, there was no statistically significant difference between the products regardless of the hair type.

Conclusion

The most significant impact of the new cationic cellulosic polymer is the ability to provide the formulators and consumers options for silicone alternatives in hair care products. The results from the above studies have clearly shown that it is as effective as the traditional amodimethicone polymers in many aspects. In addition to the before mentioned benefits, the new cationic cellulosic polymer provide additional benefits, including:

increase in biocarbon and natural content in formula
high weight efficiency – low use level
water dispersibility
viscosity enhancer
good compatibility with a broad range of variuos surfactants and thickeners
versatility in various formulation formats
China compliance: listed in the Catalogue of Cosmetics Ingredients in China
no compromise on performance: it can feel like a silicone on wet/dry hair (reduction in combing force especially for damaged hair)

Due to its unique properties, this polymer can expand further into other industries, such as skin cleansing, with the same consideration of the consumer’s needs.

References

1 Report ID: GVR-4-68038-955-5
2 Ucare Extreme Polymer
3 Ucare JR-30 M Polymer or Softcat SX1300X Polymer
4 Dowsil 8500 Conditioning Agent
5 Ucare JR-30M Polymer or Softcat SX-1300X Polymer
6 Hydroxyshield Polymer or Ucare Extreme Polymer
7 Dowsil 8500
8 Ucare JR-30M Polymer
9 Dowsil 8566 Amino Fluid

Cindy Delvallé,

Application Engineer,
Dow,
Brussels, Belgium,

www.dow.com

Eve N. Suthiwangcharoen, Ph.D.,
Research Scientist,
Midland, USA,
Dow,
www.dow.com

Co-authors:

Nisaraporn Suthiwangcharoen, Dow Midland USA
Cindy Delvalle, Dow Silicones, Seneffe, Belgium
Lyndsay Leal, Dow, Collegeville, USA
Michaleen L. Pacholski, Dow, Collegville, USA
Shannon Golden, Dow Midland, USA
Jennifer Koenig, Dow Collegeville, USA
Giuseppina Lavinaro, Dow Silicones, Seneffe, Belgium