Hydroxypropyl guar hydroxypropyltrimonium chloride is an organic, cationic polymer, water-soluble quaternary ammonium derivative of guar gum.

The name defines the structure of the molecule:

• Hydroxypropyl Guar indicates that the base molecule is modified guar gum by adding hydroxypropyl (-CH₂CH (OH)CH₃) groups. Guar gum is a polysaccharide, a large molecule composed of many sugar units.
• Hydroxypropyltrimonium Chloride indicates that the modified guar gum molecule has been further modified by adding a hydroxypropyltrimonium chloride group. The "trimonium" part means that there are three methyl groups (-CH3) attached to a nitrogen atom, and the "chloride" part indicates that there is a chloride ion associated with the molecule, giving it a positive charge. This makes the molecule a type of quaternary ammonium compound often used for their antimicrobial properties.

The synthesis process takes place in several stages:

• Extraction. Guar gum is extracted from the seeds of the guar plant.
• Hydroxypropylation. Guar gum is treated with propylene oxide, a process known as hydroxypropylation. This introduces hydroxypropyl groups to guar gum.
• Quaternization. Hydroxypropyl guar is treated with trimethylammonium chloride, a process known as quaternization. This introduces the trimethylammonium chloride groups to the hydroxypropyl guar, forming Hydroxypropyl Guar Hydroxypropyltrimonium Chloride.

It occurs as a yellowish, fine powder, easily dispersible in water. Compatible with anionic, cationic, non-ionic and amphoteric surfactants.

What it is used for and where

Medical

Vaginal mucoadhesive formulations used for the preparation of vaginal gels (leave-on formulations) and vaginal douches (rinse-off formulations) determined by means of traction, rheological synergy and washout tests (1).

Cosmetics

• Antistatic agent. Static electricity build-up has a direct influence on products and causes electrostatic adsorption. The antistatic ingredient reduces static build-up and surface resistivity on the surface of the skin and hair.
• Hair conditioning agent. A large number of ingredients with specific purposes can co-exist in a hair shampoo: cleansers, conditioners, thickeners, mattifying agents, sequestering agents, fragrances, preservatives, special additives. However, the indispensable ingredients are the cleansers and conditioners as they are necessary and sufficient for hair cleansing and manageability. The others act as commercial and non-essential auxiliaries such as: appearance, fragrance, colouring, etc. Hair conditioning agents have the task of increasing shine, manageability and volume, and reducing static electricity, especially after treatments such as colouring, ironing, waving, drying and brushing. They are, in practice, dispersing agents that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioners includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners.

Guar Hydroxypropyl Trimonium Chloride imparts less friction than polyquaternium-10 but dulls the substrate used in this study (2).

Other uses

Development of a high-performance alkaline anion exchange membrane for solid-state supercapacitors and flexible rechargeable zinc-air batteries (3).

The most relevant studies on this chemical compound have been selected with a summary of their contents:

Guar Hydroxypropyl Trimonium Chloride studies

Typical commercial product characteristicsGuar hydroxypropyltrimonium chloride

• Molecular Formula  C₆H₁₆NO₂.xCl.    
• CAS  71329-50-5 

Synonyms

• Guar gum, 2-hydroxy-3-(trimethylammonio)propyl ether,
• Guar gum, ether with 3-chloro-2-hydroxypropyltrimethylammonium chloride
• Guar hydroxypropyltrimonium chloride
• Guar cationic gum

References________________________________________________________________________

(1) Rossi, S., Bonferoni, M. C., D’Autilia, F., Sandri, G., Ferrari, F., Caramella, C., ... & Gasparri, F. (2014). Associations of natural polymers to modulate mucoadhesion of vaginal rinse-off and leave-on formulations. J. Drug Deliv. Sci. Technol, 24, 496-502.

Abstract. The aim of the present work was the development of vaginal mucoadhesive formulations. A irst phase of the work was devoted to the investigation of mucoadhesive properties of a series of polymers and of their associations by means of rheological synergism approach. The associations of xanthan gum with guar hydroxypropyl trimonium chloride and lambda carrageenan were characterized by the highest mucoadhesive potential. Such associations were subsequently employed for the preparation of vaginal gels (leave-on formulations) and vaginal douches (rinse-off formulations). The mucoadhesive potential of the formulations was determined by means of different approaches: rheological synergism, tensile and wash away tests. Depending on the polymer associated to xanthan gum (guar hydroxypropyl trimonium chloride or lambda carrageenan) it was possible to modulate the mucoadhesive properties of complex systems such as leave-on and rinse-off formulations. The results obtained conirm that xanthan gum in association with natural polymers is suitable to confer mucoadhesive properties on vaginal formulations.

(2) Wu W, Alkema J, Shay GD, Basset DR. Quantitative methods for evaluating optical and frictional properties of cationic polymers. J Cosmet Sci. 2001 Jan-Feb;52(1):51-65.

Abstract. This paper presents three quantitative methods to examine gloss, opacity, and friction of cationic polymers. The adsorption of cationic polymers onto hair and skin can be regarded as a thin film coating. Therefore, optical and frictional properties of polymer films are of significant relevance to the applications of cationic polymers in hair care products. Such properties reflect the desirable hair condition attributes consumers seek in shampoo and conditioner products. Using these test methods, polyquaternium-10 and cationic guar samples of varying molecular weight and cationic substitution were compared. The effect of an anionic surfactant, sodium dodecyl sulfate (SDS), on polymer film properties was also investigated. Neat guar hydroxypropyl trimonium chloride imparts less friction than polyquaternium-10 but dulls the substrate employed in this study. The optical data show that polyquaternium-10 provides greater film clarity and gloss than cationic guars. In the presence of SDS, polyquaternium-10 also displays similar or lower friction than cationic guar. The comparative optical and frictional results are in good agreement with the visual assessment of the cationic polymer films. These results clearly demonstrate that polyquaternium-10 exhibits superior film properties in the forms of both neat polymer and polymer/surfactant complex. In addition, microscopic techniques such as scanning electron microscopy (SEM) and atomic force microscopy (AFM) provide powerful explanations for the differences noted between the two popular classes of cationic polymers. The test methods described in this paper can be utilized to differentiate the upper performance potential of cationic polymers. These objective and standardized test methods derived from the coatings industry are not affected by the variability of hair or the formulation complexity of end products. They can be useful tools in the product development process in quickly screening the relative performance of different polymers.

(3) Wang, M., Xu, N., Fu, J., Liu, Y., & Qiao, J. (2019). High-performance binary cross-linked alkaline anion polymer electrolyte membranes for all-solid-state supercapacitors and flexible rechargeable zinc–air batteries. Journal of Materials Chemistry A, 7(18), 11257-11264.

Abstract. Development of a high-performance alkaline anion-exchange membrane (AAEM) is a subject of intense research owing to its potential applications in polymer electrolyte membrane fuel cells, supercapacitors and zinc–air batteries. However, high ionic conductivity is still a major challenge for AAEM. Herein, we developed a novel binary cross-linking strategy by employing glutaraldehyde (GA) and pyrrole-2-carboxaldehyde (PCL) as binary cross-linkers for fabricating a highly conductive, flexible and thin AAEM composed of poly(vinyl alcohol)/guar hydroxypropyltrimonium chloride (PGG-GP). The resultant PGG-GP membrane delivered an exceptional hydroxide conductivity of 0.123 S cm−1 at room temperature, while retaining high swelling resistance, outstanding mechanical strength and excellent thermal stability. An activated carbon-based all-solid-state supercapacitor exploiting the PGG-GP membrane as an electrolyte demonstrated a long cycling life of 8000 charge/discharge cycles with 87.5% capacitance retention. Moreover, the flexible all-solid-state zinc–air batteries comprising the PGG-GP polymer electrolyte displayed a peak power density of 50.2 mW cm−2 and a superior cycling stability (9 h @ 2 mA cm−2). These merits make the PGG-GP membrane very promising for application in both all-solid-state supercapacitors and flexible, rechargeable zinc–air batteries, providing new opportunities for improving the ionic conductivity in all-solid-state devices.