Leveraging nature

Consumers are more eco-conscious which require all the key ethical and sustainability elements, 
but product efficacy and convenience in hair 
care applications are also critical. They are looking for performance-focused products that are attainable while addressing clean beauty concerns. To answer consumer needs, Dow developed a series of new ingredients meeting both sustainability and performance aspects, allowing consumers to enjoy a complete sustainable routine.

Dow’s first cationic dextran technology is a deposition aid for shampoo for sustainable beauty care. Prepared from cane sugar via biofermentation, this bio-derived and biodegradable technology delivers benefit agents like silicones and natural oils onto the hair for lasting performance while allowing the competing cleaning action of the surfactants to remove dirt. This cationic dextran polymer has inherent, ultimate biodegradation as measured by OECD 302 and a high biocarbon content of 81% as calculated by a mass balance of its conversion from cane sugar. The polymer backbone is made from a renewable source of non-GMO sugar cane. Additionally, because of the flexible backbone, the product is readily water-soluble and cold-processable, without ethoxylation or aldehyde-based surface treatment, which makes it easier to handle than cationic cellulosic and guar derivatives which are delivered as powders.  

Unique benefits

The unique selling point of this new cationic dextran technology is that it is a very effective deposition aid for silicone. Therefore, similar benefits can be achieved using less silicone compared to cationic guar. To demonstrate the unique benefit of the cationic dextran polymer, shampoos were formulated using increasing amount of silicone emulsion from 0.5 to 1% silicone active using either the cationic dextran polymer or a cationic guar at 0.3% active. A control was formulated with 1% active silicone emulsion without any deposition aid. The silicone emulsion used is an anionic emulsion of polydimethylsiloxane hydroxyl-terminated with the INCI name: Dimethiconol (and) TEA-Dodecylbenzenesulfonate. Coefficient of friction (COF) and combing were measured on virgin brown hair and are presented in Figure 1 and 2, respectively. The cationic dextran polymer provides similar friction and enhanced wet and dry combing compared to cationic guar using half the amount of silicone emulsion, demonstrating the efficacy of the cationic dextran polymer as deposition aid.

The benefits were consumer perceivable as demonstrated by sensory panel studies (Figure 3). The shampoo containing the cationic dextran polymer provides better ease of combing and detangling on wet hair and better ease of combin on dry hair while needing less silicone. 

The cationic dextran deposition aid is highly effective but does not induce silicone build-up on the hair. As shown by five repeated shampoo treatments, the silicone deposition measured by FTIR after one and five washes are not statistically different (Figure 4, left). After five repeated treatments, the tresses treated with either the cationic dextran or cationic guar-containing shampoos are similar to the control tress without observable greasiness (Figure 4, right).

The new cationic dextran polymer technology is one-stop shop for sustainable conditioning shampoos with a natural origin content of 85% and REACH compliance.

Versatile technology

Beyond deposition aid in shampoo, Dow functionalised polysaccharide technologies can also be expanded to rinse-off conditioner applications thanks to another Dow innovation: cationic hydrophobically modified HydroxyEthylCelullose (cat-hmHEC). This versatile bio-derived and inherent primary biodegradable (according to OECD test(s) guidelines) technology has a cellulosic backbone, with 48% bio-derived content derived from non-GMO and PEFC certified wood pulp and contains a cationic functionality. This polymer is dispersible in water and can be incorporated into the formulation directly, without emulsification. While cationic charge enhances polymer deposition on hair, the hydrophobic moiety provides improved sensory benefits. Cat-hmHEC polymer provides several advantages including 1) an increase in biocarbon and natural origin; 2) inherent primary biodegradability; 3) tunable chemical structure by varying the length, level of alkyl chain substitution, and the overall charge; 4) ease of formulation due to its water-
soluble nature. Cat-hmHEC polymer was evaluated at 0.3% active level in a rinse-off formulation and compared to cationic HydroxyEthylCellulose (cat-HEC) or polyquaternium-67 (PQ-67) (0.3%) and a control conditioner without silicone or cationic polymer. For the conditioner containing silicone, aminosilicone emulsions (INCI: bis-diisopropanolamino-PG-propyl dimethicone/bis-isobutyl PEG-14 copolymer (and) polysorbate 20 (and) butyloctanol or amodimethicone) were used at a 1% silicone active level. The study was performed on bleached Caucasian hair. 

Cat-hmHEC polymer shows a significant improvement in both dry and wet combing when compared to the control (without silicone or cationic polymer) (Figure 5, up). Compared to aminosilicone polymer, a statistic difference was observed in dry, but not in wet, combing. At this level, consumers may not be able to distinguish between the treatments. When compared to cat-HEC and PQ-67, cat-hmHEC polymer performs significantly better in both dry and wet combing (Figure 5, down), suggesting that the hydrophobe plays a role in combing force reduction.

Excessive combing or brushing can contribute to significant hair breakage as a result of bending, torsion, and interfiber friction2, 3. To evaluate the effect of cat-hmHEC polymer on hair breakage reduction, 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 breakage. Figure 6 shows reduced breakage studies of cat-hmHEC polymers against a control (conditioner without polymer) and other conditioning polymers. Hair treated with cat-HEC shows a 60% reduction in breakage when compared to control. The appearance of tangling as a result of the breakage near the tips was evident. The breakage was reduced when the hair was treated with either Bis-diisopropanolamine-PG-propyldisiloxane/bis-vinyldimethicone copolymer or cat-hmHEC polymer with > 90% breakage reduction. These results show that higher hydrophobe content provides considerable protection against breakage caused by repeated grooming. This is due to a higher surface lubrication as a result of a higher hydrophobe content, which subsequently reduces grooming forces and prevents damage caused by mechanical stress. While the propensity for hair breakage increases with hair damage, the breakage can be reduced by depositing hydrophobic materials on the cuticle surface which resemble the lipid layer of methyl eicosanoic acid (18-MEA)4, 5.

The ultimate test of performance is consumer acceptance, which can be mimicked with a trained panel test. Consumers associate “smooth” with good feel and “rough” with poor feel of the hair. The hair treated with cat-hmHEC polymer is smoother, more slippery, more aligned, less tangled, and easier to comb than tresses treated with silicone or cat-HEC polymers.

The benefits of Corn Starch

After applying a rinse-off conditioner, consumers usually apply a hair styling product.

Dow has recently developed a corn-based product family which provides natural hair styling benefits while meeting consumers’ expectations in both performance and sustainability. The two newly launched hydrolysed corn starch materials are 100% bio-based, readily biodegradable, non-GMO and can provide superior stiffness to subtle styling. These polymers are 100% natural origin hydrolysed corn starch delivered in an easy-to-use powder format. They can be dispersed in an aqueous solution to form a transparent, natural film on the hair, with comparable performance to synthetic film-formers with the added benefit of being non-hygroscopic. Besides, they inhabit a lower CO2 footprint compared to the incumbent synthetic hair styling polymers (e.g. polyvinylpyrrolidone (PVP)) while exceeding its performance in high humidity environments.  Dow hydrolysed corn starch materials set a new standard in hair styling performance and benefits. 

Designed for use in both all-natural and high-performance traditional hair styling products, application testing indicates styling performance comparable to or better than polyvinylpyrrolidone (PVP) and other corn starch fixatives. In leave-on styling applications, this new polymer family delivers superior performance in humidity resistance, curl retention and frizz control compared to other ingredients, even at low concentrations. Compatible with a wide range of natural and synthetic hair styling ingredients, Dow hydrolysed corn starches can be formulated in a variety of formats from gels, to waxes, creams and sprays – which allows for creative textures and a customised consumer experience. One of these hydrolysed corn starch (hydrolysed corn starch 2) offers the additional benefit of creating crystal clear formulations. The test results that follow demonstrate the new bio-based ingredients offer formulators an exceptional alternative for both natural and traditional hair styling without compromising performance.

A styling gel prototype was created with hydrolysed corn starch 1 to compare performance to top synthetic and natural film-formers available in the market. 

To highlight the outstanding performances of hydrolysed corn starch 1, high humidity curl retention was performed comparing My Go To Green to competitive alternatives:

• A control gel: formula without a fixative polymer
• My Go To Green: gel formulation containing 1% hydrolysed corn starch 1
• A commercial benchmark containing dehydroxanthan gum (Benchmark 1)
• A commercial benchmark containing a competitive hydrolysed corn starch (Benchmark 2)
• Gel formulation containing 1% PVP 
• Gel formulation containing 1% hydrolysed corn starch

My Go To Green hair tresses had the highest average curl retention, after 8 hours at 90% relative humidity, compared to the competitive alternatives (Figure 7).