Speciality Chemicals Magazine NOV / DEC 2024 | Page 48

A polymeric co-surfactant for mildness

Nouryon has launched Structure M3 . We report from a recent company webinar

Nouryon ’ s Structure M3 * starch ( INCI : Sodium Hydrolyzed Corn Starch Dodecenylsuccinate ) is a new polymeric co-surfactant that can be used to improve the mildness of new and existing surfactant systems , according to Maryalice Belluscio , technical service manager for personal care at Nouryon . She was speaking at a webinar to introduce it to the market .

Structure M3 takes its name from three words integral to it . It derives its functionality from maltodextrin , enabling it to manipulate the micelles in surfactant systems like sodium lauryl ethyl sulfate ( SLES ), sodium lauryl sulfate ( SLS ) and taurates to make them larger ( as measured by dynamic light scattering ) and unable to penetrate the skin layer . The result is improved mildness and lower irritation .
“ This ingredient is designed to be blended into surfactant systems that already contain a primary and a secondary surfactant ,” Belluscio said .
It uses a hydrophilic polysaccharide derived from non-GMO corn that is further modified with a hydrophobe to create both a hydrophilic and hydrophobic block to the polymer . These block mimic and interact with more traditional surfactant systems , thus enabling Structure M3 to be incorporated into the micelle easily and increasing its size .
Structure M3 is compatible with multiple additive and preservative systems commonly used in cleansing formulations . This ingredient is currently available globally , except in China , where the registration process is ongoing . Nouryon states that its product offers the following green benefits , notably by being :
11.25 % SMCT / 3.75 % CAPB 9.375 % SMCT / 3.125 % CAPB / 2.5 % M3
6 % SMCT / 2 % CAPB 2.25 % SMCT / 0.75 % CAPB / 5 % M3
11.25 % AOS / 3.75 % CAPB / 0 % M3 7.5 % AOS / 2.5 % CAPB / 5 % M3
6 % SLES / 2 % CAPB / 0 % M3 5.625 % SLES / 1.875 % CAPB / 0.5 % M3
11.25 % SLES / 3.75 % CAPB / 0 % M3 7.5 % SLES / 2.5 % CAPB / 5 % M3
17 % lower irritation potential
59 % lower
19 % lower
10 % lower
23 % lower
• Naturally-derived , with an RCI 77 % and a NOI of 0.85
• Readily biodegradable ( OECD 301B )
• Non-GMO
• Cold-water processable at 0.5-5.0 % active
• Ethylene oxide- , 1,4-dioxane- , palm- & preservative-free
Irritation potential
Although there is also data on its use with ALS and taurate systems , Belluscio focused on the use of Structure M3 with SLES / cocamidopropyl betaine ( CAPB ) systems . This system is widely used in personal care applications .
When Nouryon incorporates Structure M3 into a surfactant system , it keeps the overall surfactant system consistent while maintaining the ratio of the two primary and secondary surfactants . As the level of Structure M3 increases , so does the average size and consistency of the micelles .
The company used a zein solubilisation assay to confirm the mildness of systems with and without M3 because this is “ an in vitro method that allows us to predict the irritation
0 % 20 % 40 % 60 % 80 % 100 %
Figure 1 – Zein solubilisation assay for formulations with & without Structure M3
potential of a formulation without having to perform animal testing ,” said Belluscio .
Zein protein is similar to keratin in skin and its solubilisation is widely considered to be an indicator of the mildness of a surfactant formulation . The more that is solubilised , the harsher the system . Nouryon tested three systems with and without the addition of M3 and at 8 % and 15 % total surfactant to be representative of face wash and shampoo formulations respectively :
• SLES / CAPB , which are representative of sulfate systems
• Alpha olefin sulfonate ( AOS )/ CAPB systems , representative of sulfate-free systems
• Sodium methyl cocoyl taurate ( SMCT )/ CAPB , representative of mild , amino acid-based , sulfate-free systems The results ( Figure 1 ) showed significant reductions in irritation potential for all of the formulations containing Structure M3 . “ Based on this test , we can recommend a use level of 0.5-5 % Structure M3 in specific surfactant systems ,” Belluscio said .
48 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981