Conditioning polymers in today's shampoo formulations - efficacy, mechanism and test methods

Area of Science:

• Cosmetic Science
• Polymer Chemistry
• Surface Science

Background:

• Modern shampoos offer more than cleansing, with consumers seeking conditioning, smoothing, and improved lather.
• Cationic polymers are key ingredients for achieving these multifunctional benefits in hair care formulations.
• The demand for effective conditioning polymers in shampoos continues to grow, driving research into novel materials.

Purpose of the Study:

• To evaluate the conditioning efficacy of various cationic polymers in shampoo systems.
• To investigate the underlying mechanisms responsible for the conditioning effects of these polymers.
• To compare the performance of Polyquaternium 44 against other common conditioning agents.

Main Methods:

• Formulation of shampoos containing sodium lauryl ether sulphate and different cationic polymers (Polyquaternium 7, 10, 11, cationic guar gum, Polyquaternium 44).
• Assessment of shampoo performance using combing force measurements, sensorial analysis (hair feel, lather creaminess).
• Analysis of polymer deposition on hair using atomic force microscopy and electrokinetic measurements (streaming potential).

Main Results:

• All tested cationic polymers improved shampoo formulation performance.
• Polyquaternium 44 demonstrated the best conditioning properties on wet hair, with good removability and no build-up.
• High molecular weight cationic polymers, like Polyquaternium 44, are effective conditioners, with their branched structure potentially enhancing performance.

Conclusions:

• Cationic polymers significantly enhance shampoo conditioning properties.
• Polyquaternium 44 offers superior wet hair conditioning without compromising removability or causing build-up.
• The conditioning mechanism involves polymer loops extending from the hair surface, reducing inter-fiber friction.