In recent years, quaternized guar has become the polymer of choice for both hair and skin cleansers. It is often used as the conditioner and moisturizer in two-and-one shampoos and body washes. The polymer is unique in that it is derived from natural source (guar), and does not build up on hair after repeated usage. This article demonstrates comparative differences of the guar polymer to other similar polymers. In addition, several model formulas with procedures, for a variety of applications (skin care, hair care etc.) are provided for the formulating chemist.

Here are some guar facts:

• The word “guar,” derived from Sanskrit, means “food for cows.”
• It belongs to the legume family.
• It is derived from the guar bean that is 15% hull, 45% germ and 40% endosperm.
• 90% is grown in northwest India. Five to 10% is grown in Pakistan.

Guar powder has many applications. In textiles, it strengthens yarn and keeps it smooth during printing and production. The powder is also used to increase the wet end strength of paper. A major application is to thicken water for use in oil exploration. In addition, guar has applications in explosives, firefighting and mining.

Personal Care Use
For personal care, the quaternized form (guar hydroxypropyltrimonium chloride), is widely used in hair care, liquid hand soaps and moisturizing body washes.
It has several advantages over other cosmetic polymers:

• It is a natural renewable resource;
• It conditions without polymer buildup;
• It is biodegradable and
• It is economical compared to other cellulosic polymers.

A valuable property of guar is its ability to hydrate in cold water and build viscosity. It forms a colloidal thixotropic dispersion in cold water. The rate of hydration is dependent on processing techniques. Typically, complete hydration occurs within 30 minutes. Recent improvements have produced guar that will hydrate within five minutes. A faster rate of hydration reduces manufacturing time.

Polymer Buildup (a comparative study):
The quaternized form is used in shampoos and conditioners to facilitate combing properties and provide a moisturizing effect. The positively-charged nitrogen bonds with the negatively-charged hair follicle forming a polymeric film. This bond provides a smooth and soft feel to the hair. With repeated use it is important that the polymer does not build up on the cuticle surface. Buildup results in a dull, lifeless appearance to the hair.

In order to compare polymer buildup, solutions of Polyquaternium 10 and guarhydroxypropyltrimonium chloride were prepared at 0.5%. Here is the procedure:

1. Damaged hair fibers (twice bleached and permed) are soaked in ethanol followed by rinsing three times with a 12.0% active TEA lauryl sulfate solution.
2. Each tress is soaked for 30 seconds in the 0.5% test solutions.
3. Each tress is washed with a 1.0% active sodium lauryl sulfate solution.
4. The soaking and washing is repeated five times.
5. After drying, the hair fibers are observed with a 200X microscope.

The study indicates that the hair fiber treated with polyquaternium 10 showed irregular polymer buildup. The guar hyroxypropyltrimonium chloride showed no evidence of buildup.

Quaternized Guar
The quaternized derivative is available as a fine powder in two forms: self-hydrating and non-self-hydrating. The formulator can choose depending on the application. The self-hydrating is by far the most widely used for personal care cleansing products. It is much easier to formulate and readily hydrates in water. The powder is slowly dispersed into the vortex of water, which is blended at room temperature. After complete dispersion, the water temperature is increased to 40°C and blended for 30 minutes. The quaternized quar will be completely hydrated. Add other components, (surfactants, pearling agents, etc.). Heat to 65°C until the product is homogeneous.

Non-self-hydrating guar does not hydrate until the pH is neutral. The viscosity is easier to handle at this stage. This type is used more for products that have low available water. The powdered quaternized guar is dispersed at room temperature and blended for 30 minutes. The pH will be 9.0-10.0. Very little buildup will occur. The other components are then added and the pH is adjusted to 6.0-7.0. The guar will then hydrate and the viscosity will be more manageable.
The function of both types of guar is identical.

Other Derivatives
Besides cationic guar, there are other derivatives to choose from including carboxymethylhydroxypropyl guar, hydroxypropyl guar and hydrophobically modified guar. The quaternized and propoxylated derivative are the two most widely used for personal care products.

Quaternized guar is also known to enhance the substantivity oil on to hair fibers. This combination is commonly used in 2-in-1 shampoos. When properly balanced, the two components provide excellent wet combing without buildup.  

Formulations
The following cleansing formulas were developed to provide maximum performance and meet the consumer’s criteria for natural (renewable resources), and diethanolamine free. Also, many are ethoxylate free.

All-Natural Moisturizing Shampoo
(Prop. 65 Friendly)

Ingredients:	%Wt
Sodium cocosulfate	12.5
Cocamidopropyl betaine (30%)	5.0
Cocamide DIPA	3.5
Guar hydroxypropyltrimonium chloride       (Ecopol 261) (Economy Polymers, Houston, TX)	0.5
EGMS (vegetable-derived)	0.8
Preservative	q.s.
Citric acid	q.s. to pH   6.5-7.0
Fragrance	q.s.
Deionized water	q.s. to 100.0

Procedure: Slowly disperse 4 into 9 at room temperature. After completely dispersed, heat to 40°C and hold for 30 minutes. Add 2 and 3. Slowly add 1 and 5, and heat to 65°C. Blend until completely homogeneous. Cool to 45°C. Add 6 and 8. Adjust pH with 7. Cool to 30°C and fill.

All-Natural Sulfate-Free Moisturizing Shampoo

Ingredients:	%Wt
Disodium lauryl sulfosuccinate (40%)	30.0
Cocamidopropyl betaine	8.0
Cocamide DIPA	5.0
Ecopol 261S	0.6
EGMS (vegetable-derived)	0.8
Preservative	q.s.
Fragrance	q.s.
Deionized water	q.s. to 100.0

Procedure: Slowly disperse 4 into 8. When completely dispersed (30 minutes), heat to 40°C. Add 2 and 3 and blend until completely dispersed. Slowly add 1 and 5, and heat to 65°C. Blend until completely homogeneous. Cool to 50°C. Add 6 and 7, and cool to 30°C.

Comments: This formula contains all naturally-derived components. It is also sulfate-, DEA- and ethoxylate-free and conforms to Proposition 65 protocol. Ecopol 261S is a natural skin moisturizer.

Mild Two-in-One Shampoo

Ingredients:	%Wt
Disodium cocoamphodiacetate (50%)	35.0
POE-20 sorbitan monopalmitate	4.5
Ecopol 261S	0.4
Isostearamidopropylmorpholine lactate (25%)	2.5
Sodium laureth sulfate (70%)	15.0
EGDS (vegetable derived)	1.8
Citric acid	q.s. to pH 6.5-7.0
Fragrance	q.s.
Preservative	q.s
Deionized water	q.s. to 100.0

Procedure: Disperse No. 3 into No. 10 at room temperature. After 30 minutes, heat to 65°C. Add Nos. 1, 2, 4, 5 and 6. Heat to 70°C , and hold until No. 6 is completely melted. Cool to 45°C and add No. 8 and No. 9. Adjust pH with No. 7. Cool and fill.

Leave-On Hair Conditioner

Ingredients:	% Wt.
Isostearamidopropylmorpholine lactate (25%)	6.0
Ecopol 261S	0.2
Citric acid	q.s. to pH 5.0-5.5
Deionized water, fragrance, preservative	q.s. to 100.0

Procedure: Slowly disperse No. 2 into deionized water. When dispersed, heat to 50°C. Add No. 1 and adjust pH with No. 3. Add fragrance and preservative. Cool to 30°C and fill.

Emollient Liquid Hand Soap

Ingredients:	%Wt.
Ammonium lauryl sulfate	40.0
Isostearamidopropylmorpholene lactate (25%)	5.5
EGDS (vegetable derived)	1.0
Ecopol 261	0.5
Citric acid	q.s. to pH  6.0-6.5
Preservative	q.s.
Water, dye, fragrance	q.s. to 100.0

Procedure: Disperse Ecopol 261 in water. With continuous blending, heat to 50°C. Add Nos. 1, 2 and 3. Heat to 75°C and hold until the EGDS is completely dispersed. Cool to 50°C and add No. 6, dye and fragrance. Adjust pH if needed. Cool to 30°C and fill.

Conclusion
Natural, sustainable and Proposition 65-friendly are some of the key words used to characterize personal care products today. Quaternized guar meets all these criteria. The quaternized guar does not build up on the hair after multiple washings; it is easy to handle, relatively low cost and compatible with most other raw  materials.
As the next generation of products is developed, this natural conditioner should continue to be a special component that provides added value to skin cleansers, shampoos and hair conditioners.

References:

1. Whistler, R.L. and Hymowitz, T., Guar Agronomy, Production, Use, Industrial and Nutrition, Purdue University Press, 1979.
2. Lundmark, L., “Comparative Buildup Study Using a Lumicrese Dye Test Procedure,” Aug. 1999.
3. Schoenberg T. G. and Chowdhary Manny Ph.D., “Formulating with Quaternized Guar,” Happi, Sept. 2001.

---

About the Author
Tom Schoenberg is a consultant for the personal care industry and has been involved in  formulating new products for over 50 years. He is a graduate of Northwestern University with a bachelor’s degree in chemistry.  Most of Schoenberg’s career has been dedicated to product development of raw materials. He has authored many articles related to the application of specialty surfactants and hair conditioners. In addition, he holds several patents in this field. More info: Tom Schoenberg, tom@schoenbergconsulting.com; www.schoenbergconsulting.com