Hydrolyzed Corn Starch: Sustainable Alternative to Synthetic Styling Polymers for Clear Hair Gels
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Presented by: Cindy Delvalle
Introduction: The primary ingredient in a styling gel is a styling polymer, which maintains the shape and hold of the hair. Synthetic vinyl polymers such as polyvinylpyrrolidone (PVP) are widely used styling agents. These polymers provide good hold, are water soluble so they can be easily washed out of hair, and they are compatible with many rheology modifiers (carbomer) and hydroalcoholic solutions. However, synthetic materials are unfavorable due to their sustainability profile. Clear and sustainable hair fixatives have long been desired, as consumers associate clarity with superior quality and purity. Hydrolyzed corn starch (HCS) is a bio-based, cold water dispersible, film forming polymer which allows formulators to create clear compositions with superior hold and humidity resistance compared to synthetic fixatives such as PVP.
Methods: Hair gel compositions with HCS up to 5% and carbomer up to 1% have been formulated. The turbidity in NTU (nephelometric turbidity units) was measured. Curl compression was measured by applying 0.3g of hair gel to 8-inch, 3g virgin medium brown hair tresses. The force required to compress the curl to 25% of its original diameter was measured in triplicate. Curl retention was measured at 25°C and 80% relative humidity over a period of 24 hours and at 25°C and 90% relative humidity over a period of 8 hours. A vapor absorption study was conducted to compare HCS and PVP. Each fixative polymer was exposed to humidity levels of 10%, 30%, 50%, and 70% at room temperature (25°C). The stability of HCS in hydroalcoholic solutions was also studied.
Results: The hair gel composition of HCS up to 5% and carbomer up to 1% provides turbidity of less than 20 NTU and appears clear to the human eye. The turbidity of the gel with HCS remains below 20 NTU after 30 days at low temperature (4°C), room temperature (20°C) and high temperature (40°C). Hair gel with 5% HCS had comparable stiffness performance versus a comparative formula with PVP. Data indicated HCS containing hair gel can achieve greater than 95% curl retention performance at 80% relative humidity over 24 hours and 90% relative humidity over 8 hours. However, a comparative formula where the HCS was replaced with PVP had less than 30% curl retention under the same test conditions. Curl retention performance for PVP is dose dependent; it declines quickly as a function of PVP concentration. On the other hand, HCS containing gel formula maintained its curl retention performance at levels ranging from 1-5%. The superior high humidity curl retention of HCS is attributed to lower water sorption. At 70% relative humidity PVP had higher water sorption compared to HCS. HCS is stable in aqueous solutions containing up to 10% ethanol.
Conclusion: The HCS in this study is a non-GMO, biodegradable, 100% natural origin (ISO 16128) hair styling polymer with excellent gel clarity in water-based formulas. Application test results demonstrate optical clarity, hair stiffness, and high humidity curl retention comparable to or better than PVP and other natural hair fixatives. It is compatible with rheology modifiers commonly used in hair gels such as carbomer. It is an excellent choice for high performing, clear and naturally derived products aligned with consumer needs.
Methods: Hair gel compositions with HCS up to 5% and carbomer up to 1% have been formulated. The turbidity in NTU (nephelometric turbidity units) was measured. Curl compression was measured by applying 0.3g of hair gel to 8-inch, 3g virgin medium brown hair tresses. The force required to compress the curl to 25% of its original diameter was measured in triplicate. Curl retention was measured at 25°C and 80% relative humidity over a period of 24 hours and at 25°C and 90% relative humidity over a period of 8 hours. A vapor absorption study was conducted to compare HCS and PVP. Each fixative polymer was exposed to humidity levels of 10%, 30%, 50%, and 70% at room temperature (25°C). The stability of HCS in hydroalcoholic solutions was also studied.
Results: The hair gel composition of HCS up to 5% and carbomer up to 1% provides turbidity of less than 20 NTU and appears clear to the human eye. The turbidity of the gel with HCS remains below 20 NTU after 30 days at low temperature (4°C), room temperature (20°C) and high temperature (40°C). Hair gel with 5% HCS had comparable stiffness performance versus a comparative formula with PVP. Data indicated HCS containing hair gel can achieve greater than 95% curl retention performance at 80% relative humidity over 24 hours and 90% relative humidity over 8 hours. However, a comparative formula where the HCS was replaced with PVP had less than 30% curl retention under the same test conditions. Curl retention performance for PVP is dose dependent; it declines quickly as a function of PVP concentration. On the other hand, HCS containing gel formula maintained its curl retention performance at levels ranging from 1-5%. The superior high humidity curl retention of HCS is attributed to lower water sorption. At 70% relative humidity PVP had higher water sorption compared to HCS. HCS is stable in aqueous solutions containing up to 10% ethanol.
Conclusion: The HCS in this study is a non-GMO, biodegradable, 100% natural origin (ISO 16128) hair styling polymer with excellent gel clarity in water-based formulas. Application test results demonstrate optical clarity, hair stiffness, and high humidity curl retention comparable to or better than PVP and other natural hair fixatives. It is compatible with rheology modifiers commonly used in hair gels such as carbomer. It is an excellent choice for high performing, clear and naturally derived products aligned with consumer needs.