Introduction of Cationic Conditioner Polyquaternium-7， Polyquaternium 22 and Polyquaternium 39

Polyquaternium is widely used in shampoo, typical type is polyquaternium-7 which is a good balance of price and quality. Hereby we’d like to introduce the family of this series to you as a reference.

Mechanism of Action of Polyquaternium in Hair Care

1. Charge Interaction

Charge interaction refers to the attraction of positively charged cationic conditioning agents to the negatively charged hair surface. Most water-soluble cationic polymer conditioners adhere to hair in this manner, providing excellent conditioning effects on wet hair.

2. Flocculation Effect

The flocculation effect occurs during the dilution process of shampoo. Washing and bathing generally take place above the critical micelle concentration (CMC) of the system's surfactants. During this process, polyquaternium remains soluble. However, during rinsing, the surfactant is diluted to near its CMC, causing polyquaternium to form coacervate complexes with anionic and amphoteric surfactants in the system. This phase separation or coacervation is known as the "lockhead effect." The coacervate, a gel-like phase containing a high amount of cationic charge, attaches the polymer to the negatively charged hair surface, forming a transparent film while the surfactant is washed away. The coacervate contains water and small particles of hair care ingredients such as silicones or anti-dandruff agents like zinc pyrithione (ZPT). The coacervate acts like a cage, protecting the hair care ingredients. When rinsed to a certain extent, the coacervate dissolves, releasing the hair care ingredients onto the scalp or hair. Factors affecting flocculation include the chemical structure, molecular weight, and charge density of the cationic polymer. Generally, cationic polymers with high charge density form more coacervate; higher molecular weight cationic polymers generate more coacervate. More coacervate improves the dry and wet combing properties (slipperiness) of the shampoo. However, excessive coacervate can lead to localized deposition, making hair less light and voluminous.

Examples of Polyquaternium in Hair Care

Based on raw material sources and polymer structure, polyquaternium can be divided into two categories:

1. Semi-synthetic polyquaternium: Natural polymers modified by quaternization.

2. Synthetic polyquaternium: Polymers formed by homopolymerization of cationic monomers or copolymerization with other monomers.

Different models or brands of cationic conditioners with the same INCI name may vary in molecular weight or charge density, leading to significant differences in performance. Combining different conditioners can have synergistic effects, complementing each other's advantages.

1. Semi-Synthetic Polyquaternium

PQ-10 (Polyquaternium-10)

Polyquaternium-10 is an important semi-synthetic polyquaternium and was the first cationic polymer used in conditioning shampoos. Its typical structure is shown that Hydroxyethyl groups are added to the hydroxyethyl cellulose (HEC) backbone to alter its crystalline structure, giving it a hydrophilic polysaccharide structure that disperses easily in water. Quaternization of HEC introduces multiple cationic sites, attracting anionic ends of surfactants and promoting adsorption on the negatively charged hair surface. Polyquaternium-10 forms a uniform, transparent, and glossy film, improving hair appearance. However, prolonged exposure to air can make hair sticky or flat due to moisture absorption. Different grades of Polyquaternium-10 vary in molecular weight and charge density.

Cationic Guar Gum

Cationic guar gum is produced by reacting guar gum with a cationic etherifying agent. It has excellent safety and a long history of use. It softens and smooths hair, increases skin softness, and reduces skin irritation. Its unique branched structure and low cationic charge density prevent excessive buildup on hair. It has excellent biodegradability and strong electrolyte resistance, making it suitable for "salt-type" conditioning shampoos.

Modified Chitosan

Chitosan is derived from chitin, a nitrogen-containing natural polysaccharide widely found in nature, by alkaline hydrolysis removing more than 55% of acetyl groups. The basic unit of chitosan is glucose with amino and hydroxyl groups, making it highly reactive. Quaternization of the amino groups increases water solubility and water retention, making it suitable as a moisturizer in cosmetics. Quaternized chitosan also has emulsifying and thickening properties. It forms a protective film on hair, reducing friction and protecting hair. This polysaccharide is hydrophilic, non-toxic, and non-irritating, making it safe for use.

Quaternized Hydrolyzed Protein

Hair is mainly composed of keratin, so hydrolyzed protein has high affinity for hair, is easily absorbed, and provides nutritional benefits and film-forming properties, making it suitable as a conditioner in hair care products. Damaged hair, with exposed protein, increases hydrophilicity, allowing water-soluble proteins to bind more easily. Quaternized hydrolyzed protein combines the water solubility and nutritional benefits of hydrolyzed protein with the adsorption properties of quaternization, forming a protective film on hair, enhancing shine, and improving manageability.

Polyquaternium-67

Polyquaternium-67, a quaternized hydroxyethyl cellulose with trimethylamine and lauryldimonium substitutions, retains the excellent properties of Polyquaternium-10 and has moderate lipophilic modification, providing excellent wet and dry combing properties.

2. Synthetic Polyquaternium

Synthetic polyquaternium includes a wide range of products, mostly homopolymers of cationic monomers or copolymers with other polymerizable monomers. Common cationic monomers include diallyldimethylammonium chloride, methacrylamidopropyltrimethylammonium chloride, and methacrylamidopropyldodecyldimethylammonium chloride. Common comonomers include acrylamide, acrylic acid, acrylates, and vinylpyrrolidone.

Polyquaternium-6

A homopolymer of diallyldimethylammonium chloride with a molecular weight of 80,000-120,000. It has high charge density, excellent wet and dry combing properties, and leaves hair soft and voluminous when dry.

Polyquaternium-47

A terpolymer of acrylic acid, methyl acrylate, and methacrylamidopropyltrimethylammonium chloride. Known for its strong detangling ability, it provides excellent wet combing and anti-tangling properties, typically used at 1.5% in shampoos.

Polyquaternium-28

GAFQUAT®HS-100 by International Specialty Products is a copolymer of vinylpyrrolidone and methacrylamidopropyltrimethylammonium chloride, offering good conditioning effects.

Polyquaternium-22

A copolymer of acrylic acid and diallyldimethylammonium chloride with a molecular weight of 100,000-500,000. It is a viscous, transparent to slightly cloudy liquid used in rinse-off products, compatible with most amphoteric and anionic surfactants. It sets hair, improves dry and wet combing, and is used in clear shampoos.

Polyquaternium-7

Introduced in the 1990s, it is a copolymer of dimethyldiallylammonium chloride and acrylamide with an average molecular weight of about 500,000. It has low charge density, excellent wetting and softening properties, good foam stabilization and thickening effects without cumulative deposition, and is widely used in 2-in-1 shampoos. It is compatible with anionic surfactants and suitable for clear formulations. Shengqing Materials have two types of polyquaternium-7, one is 10% solid content which is regular type, the other is 40% solid content which could save the freight charge.

Polyquaternium-11

A copolymer of vinylpyrrolidone and quaternized dimethylaminoethyl methacrylate with an average molecular weight of about 1,000,000. It forms a transparent, non-tacky continuous film. Compared to Polyquaternium-10, it lacks a polysaccharide hydrophilic structure, maintaining better volume on hair.

Polyquaternium-44

Introduced by BASF, it is a copolymer of N-vinylpyrrolidone and quaternized vinylimidazole. It provides excellent conditioning without excessive deposition, has good affinity for hair and scalp, and effectively reduces irritation. It helps maintain hairstyle in windy conditions.

Polyquaternium-55

Styleze W-10/W-20 by International Specialty Products is a terpolymer of vinylpyrrolidone, dimethylaminopropylacrylamide, and dodecyldimethylammonium chloride.

Polyquaternium-39

A terpolymer of acrylic acid, acrylamide, and diallyldimethylammonium chloride with excellent conditioning and setting properties, used to maintain curls.

Polyquaternium-74

A copolymer of anionic acrylate monomers and a patented cationic monomer (Rhodia). When used in shampoo, it coacervates and deposits on hair surfaces, providing conditioning. Coacervation depends on the surfactant base, pH, and ionic strength of the formulation. Commercial Polyquaternium-74 is a blend of water, dimethicone, Polyquaternium-74, and laureth-7 (Polycare Boost, PQ-74 DIM, Rhodia). It is mainly used in 2-in-1 shampoos and conditioners at 2.5% PQ-74 DIM (equivalent to 0.2% PQ-74 and 2.5% dimethicone). It provides excellent conditioning, imparts shine, and neither PQ-74 nor dimethicone accumulates on hair.