1	Quaternary Compounds Hardness and Softness of Cationic Materials April, 2005
2	Hair The isoelectric point of untreated hair is 3.7. Using the Henderson Hasselbasch equation, it is clear that when the pH is below this 3.7 the hair is cationic, and when the pH is above 3.7, the hair is anionic
3	Conditioners Hair in its normal state has certain oils, sebum and other components present on it’s the surface. When a detergent is used on the hair, these materials can be removed, leaving the hair stripped of its natural conditioning oils. Stripped hair is generally dry, raspy, dull and has problems with static electricity which results in a condition called, “fly away”. The ability to treat the hair to remove these undesirable properties is the most basic aspect of conditioning. There are several others.
4	"Fatty and Silicone quats can..." Fatty and Silicone quats can be applied to overcome these undesirable attributes. However:
5	"The use of quats in..." The use of quats in hair care products can be problematic, since many of these materials are not compatible with anionic materials. This incompatibility can be manifested as a precipitate, or as cloudiness in formulation.
6	Anionic / Cationic Complex
7	Conditioners One aspect of conditioning is wet comb, which is the ability to effortlessly comb the hair in a wet state. Wet comb relates to wetting of the hair with a surfactant to make combing easier. Another aspect of conditioning relates to providing the hair with a treatment that the consumer perceives as soft and conditioned many hours after the hair has been treated.
8	Conditioners Materials which function in wet comb are not necessarily the same as those that function as dry comb agents. The agents that best alter the feel of hair after drying are polymers and most commonly high molecular weight insoluble silicones.
9	"The advent of two in..." The advent of two in one systems that provide this type of advanced conditioning as been made possible by inclusion of polymers, often silicone polymers into hair care products. In recent years this type of conditioning has been achieved by inclusion of silicone fluids, oil soluble esters and making complexes of anionic and cationic surfactants that contain silicone.
10	Observation Some quats are very insoluble when added to anionic surfactant, others have improved compatibility.
11	Goal The ability to select quats that have optimum compatibility with anionic systems and minimal effect upon other attributes like foam, offer the formulator flexibility in formulating heretofore unavailable.
12	"The nature of the anionic..." The nature of the anionic / cationic interaction is key to predicting functionality, or lack of functionality of conditioners
13	Quat Structure R² \| R¹-N⁺-R³ Cl^- \| R²
14	Compounds Studied
15	Groups Studied R¹ 1. Alkyl (C₁₂) Ricinoleylamidopropyl Dilinoleylamidopropyl Cocamidopropyl R² 1. Methyl -CH₃ 2. 2-hydroxy ethyl - CH₂CH₂OH R³ 1. Methyl -CH₃ 2. Benzyl -CH₂-C₆H₅ 3. Glyceryl -CH₂-CH(OH)-CH₂-OH
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17	Anionic Compatibility
18	Anionic Compatibility Procedure Prepare a 10% active solution of SLS and SLES-3 Prepare a 10% active solution of Quat to be tested.
19	Anionic Compatibility Procedure (cont’d) Titrate 10% solution of quat into 100 grams of 10% solution of anionic. End point is cloudiness or precipitate.
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26	Results All quat compounds reached a cloud point when titrated into anionic. However the amount necessary to reach the haze point was different and the nature of the end point was different. The so-called hard quats have very little tolerance for anionic, forming insoluble precipitates with very little addition. Quaternary compounds having intermediate hardness show compatibility with anionic surfactants at near stoichiometric amounts, but do eventually haze. Soft quats do not exhibit a haze, but rather show a clear gel.
27	Foam in Anionic Surfactants
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31	Rubine Dye Test
32	Rubine Dye Test TREATMENT SOLUTIONS 0.5% Active Quat.
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36	"All quat solutions" All quat solutions, with the exception of three, (AEG, AMG, CaMG) exhibited cationic sub stantivity when delivered to hair tresses in a 0.5% aqueous solution. It is likely that these quat solutions did not exhibit substantivity because of their increased water solubility. Quat DMG, containing a glyceryl group, did exhibit cationic substantivity.
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40	"No substantivity was observed when..." No substantivity was observed when quat solutions were delivered from a 10% active, anionic solution of surfactant. (SLS and SLES). The test measures cationic deposition as opposed to deposition of a compound of any nature. Since the quat and anionic form a complex, the deposited material is not cationic and consequently does not provide a color when tested with the dye test. More representative of the deposition is combing force.
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43	"Quaternium compounds can be classified..." Quaternium compounds can be classified as hard or soft by their ability to form gelled systems with anionic systems. Cationic systems that form a gel at near stoichiometric amounts are classified as “soft”, those that form precipitates of haze without appreciable viscosity build up are classified as “hard” quats.
44	"“Soft quats" “Soft quats” can produce foam in the systems they gel, albeit at levels below the volume of foam generated by the anionic, per se. This gellation is interesting since in some instances, it does not adversely affect foam. This means that the selection of the proper quat may allow for alkanolamid replacement.
45	"Quaternium compounds titrated with sodium..." Quaternium compounds titrated with sodium laureth-3-sulfate (SLES) produced greater viscosities with amido quats. The exception were amido quats containing a benzyl group, which exhibited a low viscosity in SLES.
46	"Compounds that contained a benzyl..." Compounds that contained a benzyl group, or were a alkyl rather than amido, (i.e. AMB, AME, AMG, AMM, AEB, AEG), precipitated at lower levels of titration and are consequently classified as “hard quats”.
47	"Overall" Overall, all quat/anionic solutions tested had less foam than when the anionic itself was tested. This was true for both SLS and SLES. With the exception of quats AEG, AMG, and CaMG, and the negative control, all 0.5% active, aqueous solutions of quaternium compounds produced positive results for cationic substantivity, when evaluated per se.
48	"In aqueous solutions of anionic..." In aqueous solutions of anionic surfactants, all quat solutions, including the positive control (polyquaternium 10), produced negative results. This is thought to be due to the fact that there is no net positive charge of the hair, due to the fact that the anionic and cationic in combination have a new zero charge. This is not to be confused with no deposition.
49	"Instrumental dry combing analysis of..." Instrumental dry combing analysis of human hair tresses treated with aqueous quat solutions confirmed conditioning, showing that quat MMM indeed performed the best, followed closely by MMG, polyquaternium 10, and the negative control.
50	"Quat MMM concluded to be..." Quat MMM concluded to be the best performer, yielding a thick, translucent gel with a viscosity well over 10,000 cps for both SLS and SLES titrations. MMM/Anionic Solutions produced an above average foam height without suppression and extended foam stability well over 24 hours or, ten times greater than SLS and SLES, controls, and positive controls (polyquaternium 10 and SLS/SLES). MMM performed equally as well in substantivity tests when delivered from an aqueous system.
51	* This study was sponsored by Phoenix Chemical (Somerville N.J.) and SurfaTech Corporation (Dacula, Ga). It was conducted by Thomas O’Lenick (synthesis) and Tim Brockman (evaluation). Thomas O’Lenick is a senior chemistry major at Georgia Southern University and Tim is a junior Chemistry major at Bloomsburg College. The applications portion of the study was directed by Steve Cochran of Phoenix Chemical.