Polyquaternium-44

Shokri, Javad, Maryam Shamseddini Lori, and Farnaz Monajjemzadeh. Journal of cosmetic dermatology 17.6 (2018): 1225-1232.

Polyquaternium-44 (PQ-44) is a cationic polymer widely applied in commercial hair care products as a conditioning agent and film former. Its functional performance is largely influenced by molecular weight, polymer type, and solution pH, which govern deposition efficacy and durability on hair fibers. In a comparative study of PQ-44, PQ-68, and PQ-87, the polymers were applied to hair at varying pH values, and deposition was assessed through hair diameter measurements using digital micrometry, complemented by optical and polarized light microscopy.

PQ-44 demonstrated superior resistance to washing at pH 6, maintaining a stable polymer layer on hair fibers. ATR spectroscopy confirmed the presence of PQ-44 and identified characteristic wave numbers associated with its cationic functional groups, indicating successful adsorption and potential electrostatic interactions with the negatively charged hair surface. The study revealed that polymer deposition increases with higher pH, with optimal performance observed near pH 9; however, PQ-44's washing durability was most pronounced at slightly acidic conditions, highlighting the balance between deposition and retention under realistic usage scenarios.

Overall, PQ-44 exhibits excellent deposition stability and strong interaction with hair fibers, making it an effective ingredient in rinse-off and leave-on conditioning formulations. Its ability to form a durable cationic film ensures enhanced manageability, improved hair texture, and long-lasting conditioning effects. This performance underscores PQ-44's suitability for high-performance hair care applications, particularly where product longevity and resilience against washing cycles are critical.

Hössel, et al. International journal of cosmetic science 22.1 (2000): 1-10.

Polyquaternium-44 (PQ-44) is a high-molecular-weight branched cationic polymer extensively applied in modern multifunctional shampoos as a conditioning agent, film former, and hair detangler. In recent studies, PQ-44 was evaluated alongside other cationic polymers, including Polyquaternium-7, 10, 11, and cationic guar gum, in sodium lauryl ether sulfate-based shampoo systems to assess wet combability, sensorial properties, and polymer deposition on hair fibers.

Hair treated with PQ-44 exhibited superior conditioning performance, demonstrated by reduced combing forces, enhanced lather creaminess, and improved tactile feel without compromising rinsability or causing build-up—a common limitation of cationic guar-based polymers. Atomic force microscopy and zeta potential measurements confirmed effective adsorption of PQ-44 on hair surfaces. The polymer's branched structure allows the cationic moieties to anchor to hair fibers, while the uncharged segments form loops projecting outward, reducing inter-hair friction and improving manageability.

Performance tests highlighted that high molecular weight is critical for efficacy, whereas an excessively high cationic charge is unnecessary. PQ-44's unique branched architecture ensures both persistent polymer deposition and ease of removal upon rinsing, delivering long-lasting conditioning effects compatible with frequent shampoo use. These properties make PQ-44 an ideal component for advanced hair care formulations, particularly in products demanding a balance of conditioning efficiency, sensory appeal, and low build-up.

This case underscores PQ-44's role as a tailor-made cationic polymer, enabling high-performance hair conditioning in modern shampoo systems.