Virgin Hair Surfaces Hair that has not been chemically treated mix of hydrophobicity and hydrophilicity As a result of its protein structure the hair surface has an isoelectric point near 3.67 as a result of a layer which insures that the surface of fatty acids will contain negatively charged covalently bound to hydrophilic sites at the the outermost ordinary pH levels of hair caresurface of the cuticle products
cystine In the hair cystine S-sulfonate UV cysteic acidThe tip portions of the hair, beingolder than the root portions - - - -therefore be more hydrophilicaffecting the nature of species thatcan bind to these sites.
greater combing damagethe surface friction of hair tips is higher This eventually results indestruction of the covalently the tip ends of hair require bound lipid layer more and a feeling of dryness at conditioning than the rest of the tips the fiber Without sufficient conditioning, the cuticle layer is eventually lost, resulting in a split end
Chemically Treated Hair Surfacespermingbleachingpermanent dyeingsignificant damage to the hair fiber tensile damage modify the surface of the hair Introducing negative charges oxidation of cystine to cysteic acid transformation of the fiber surface from a hydrophobic to hydrophilic
treated hair generally requires more conditioning than virgin hair conditioner, can prolong the health of the hair fiber
regular rinse-off conditionersnormally applied after shampoofollowed by a rinsing stepThis is the most common form ofconditioner sold.
Intensive treatment conditionersNot for daily application. They are used for intensive treatmentcontain a higher level of active ingredients that are kept on the hair for a longer period of timesold as thicker creams to provide the perception of higher conditioning.
Leave-in productslighter and can potentially provide more significantbenefits than rinse-off products everything applied stays on the hair until the nextshampoo.come in various forms, such as detanglers, leave-inlotions, and sprays.They are marketed either for single application ormultiple applications during the day. What about me?? !!!
Cationic Surfactantsthe most widely used agents incommercial productsBenefits ExamplesEffectiveness stearalkonium chlorideVersatility Cetrimonium chlorideAvailability dicetyldimonium chloridelow cost
counter anions•chloride•bromide•MethosulfateBecause of the positive charge•they are substantive to hair and bind tonegative sites on the hair surface.
The Results•hydrophobic coating on the fiber thatrender the hair softer and easier to comb• Buildup of static charge (flyaway) is also greatlyreduced as a result of this surface modification• deposition increases withincreasing negative charge on thehair surface
deposition and degree of penetration into the hair fiber interaction between cationic conditioners andthe hair fiber mainly occurs at the surface low–molecular weight materials maypenetrate the interior via intercellular diffusion Cetrimonium bromide (CETAB)can penetrate the cuticular sheath as well as cortex
Conditioner Properties and Hydrophobicity•Binding of Stearalkonium Chloride to Human Hair Type of hair Quat deposition at Quat deposition at tips roots (mg/g hair) (mg/g hair) Virgin hair 0.649 0.789 Bleached 1.62 1.83 hair more hydrophobic leads to increased deposition on hair
tricetylmonium cetrimonium chlorides chloridedicetyldimonium provide Provides heavier light to conditioning medium conditioning
Detangling and wet combing, in particular,improve significantly from monocetyl todicetyl to tricetyl quatsNote that on some types of hair, the greatersubstantivity of higher conditioning quats canlead to buildup with repeated use and result inlimp, unmanageable hair.e.gA tricetyl quat might beused, in an intensiveconditioner meant only foroccasional use.
commercial conditioners and shampoos The quaternium compounds normally used incommercial conditioners are not generallyfound in shampoosbecause of its incompatibility withcommon anionic detergents & conditioner
Example “Ethoquats.”•polyethylene glycol (PEG)•cocomonium chlorideBoth of these quats are compatible withtypical anionic detergentsIntroducing hydrophilic groupsdecreases the conditioning efficacysuitable only in light conditioning Formulationsconditioning shampoos based on ethoquats wouldnot be expected to be very effective as a result of lowdeposition of the detergent-soluble ethoquat complex
Other detergent-soluble quats :alkylamidopropyldihydroxypropyl dimonium chlorides lauryl methyl gluceth hydroxypropyl dimonium chloridehydrolyzed ginseng-saponin quaternary derivedfrom Korean ginseng saponinlow irritationthe same conditioning limitationsas the ethoquats.
Other Cationic Surfactants Behentrimonium(C22) (longer fatty chain) reduced eye and skin irritationsuperior conditioning and thickeningproperties Tallow octyl dimonium chloride provides high conditioning as a result of its twohydrophobic chains.soluble in water as a result of branchingeasier to formulate into a commercial product.
immidazoline-based quatsclaimed a softening effect on fabrics or hair. have also been disclosed led to the synthesis of ester quats that exhibitbiodegradability affect environmental safety Dipalmitoylethyl hydroxyethylmonium methosulfateGuerbet alcoholshydrolyzed keratinDistearyldimonium chloridesoy and wheat protein milk protein
Amines (with fatty chains) low pH protonation cationiccationicEmulsifiers and conditioning agentssuch as stearamidopropyl dimethylamine Different acids may have different effects on the viscosity of the final product.
Lipophilic Conditioners •long-chain fatty conditioners cetyl alcohols stearyl alcohols FunctionBoost the conditioning effects ofthe quaternary compoundsReduced in wet combing forces on hairReduced surface friction.
cationic surfactants and fatty alcohols mixturesform lamellar liquid crystal mesophases and gel networksincrease viscosityconfer stability upon emulsionsmanufacturing solids at room temperature requiring heating to incorporate into a product the cooling rate is not so rapid
Other lipidsglycol distearatetriglyceridesfatty esterswaxes of triglyceridesliquid paraffin
cationic charge densitythe higher the charge density, the lower the weightof polymer needed to neutralize all of the negativechargeon the hair. multiple points of electrostatic attachment harder to removeCare must be taken, to avoid over-conditioning as aresult of buildup with continued usedeposition of polyquaterniums increases ontreated or damaged hair.
commercial conditioners and shampooscompatible to varying degrees with anionicsurfactantsused more in shampoos than in stand-aloneconditionersthey find some use in leave-in conditioners.
Polyquaternium-10 (PQ-10)polyquaternium-7 (PQ-7)•The most frequently used polymers in commercialshampoos.•Conditioning from shampoos is significantly less thanfrom stand-alone conditioners.polyquaternium association complexesformed with sodium lauryl sulfate resistremoval from hair•Buildup•heavy coated feel on the hair•they are should carefully formulated.
some polyquaternium materials improve adhesion of the cuticle scales thereby increasing resistance to scale uplift when the hair is stressed because of Other Polymers cost, they are rare. amphiphilc polymers amphoteric polymers block copolymers graft polymers dendrimers use as conditioning agents stabilizers, deposition agents
Silicones Conditioning effectsilicone quats,Amodimethiconedimethicone,Dimethicone copolyoldimethiconol, soluble insoluble may not be as must therefore be effective in rinse-off emulsified products
Silicone emulsions can vary in:1) charge (anionic, cationic, or nonionic),2) size (microemulsion or macroemulsion),3) how they are made (mechanical or emulsion polymerization)the smaller the size of the silicone particles, the morestable the product emulsionreducing the particle size improves conditioningperformance If a preformed heat to control silicone emulsion is not used???? particle size of shear the silicone droplets
Conditioning Properties of Silicones Lubricity Spread easily on the hair surface Ease of combing and imparts a smooth, soft feel to the hair without greasiness. Dimethicone lowered frictional coefficients and surface energy of virgin hair to a greater extent than a series of cationic surfactants, including distearydimonium chloride, a very effective conditioning agent.
Measure conditioning effect on Experiment slightly bleached European hair 1Dimethiconol gums more effective in reducing dry combing forces.Dimethicone fluids wet combing was roughly the same
Exposure to Experiment silicone solutions 2 for 30 seconds followed by drying without rinsing presence of tricetylmonium chloride (quat) double deposition of all siliconesReduction in combing forces was also roughlydoubled Synergistic Effect
Effects of a series of silicone Experiment emulsions on bleached and 3 virgin hairSilicones dimethicones or amodimethiconesEmulsions anionic neutral cationicEmulsions were applied directly to thehair and combing forces measured bothbefore and after rinsing
Before rinsingreduction of combing forces by most emulsions wasgreater than 80%.After rinsingthe least change in ease of combing was found for cationicemulsions,especially those containing amodimethiconeCombing forces on virgin hair increased less than onbleached hair after rinsing The silicones were more substantive to virgin hair
Effects of Amodimethicones Experiment 3 Deposition on hair was found to increase with increasing amine content in the silicone Microemulsion in the test series that provided high conditioning was also shown to significantly reduce the color fading caused by shampoo of temporarily dyed hair
Other SiliconesCyclomethiconevolatile and will not remain on dry hair, especially after blow-dryingIt helps other conditioning agents to disperse helps improve wet combing and provides transient shine widely used as a solvent to reduce the viscosity of silicone gums with much higher molecular weights.
phenyl trimethiconehigh refractive index, close to thatof hair,commonly used in leave-inconditioners to enhance the shine ofhair fibersdimethicone copolyol phosphatesanionic functional siliconesable to complex with tertiary amines of cationichair conditioners and form effective emulsifiersand conditioners
fluorocarbon-modified organosiliconesvery hydrophobic like dimethicone; however, they areclaimed to have a lighter and more lubricious feel silicone blendsblends of these materialshaving different molecular weightsdifferent functional groups silicones with other hydrophobic oilsimprove overall conditioning benefits
2-in-1 Shampoos Silicones find important application as the primaryconditioning agents in 2-in-1 conditioningshampoos the shampoo emulsion breaks, releasing the siliconefor deposition on hair.Dimethicone The conditioning agent used mostfrequently in 2-in-1 shampoos provide good performance in shampooformulations without excessive buildup on &the hair conditioner
Newer formulationsDimethicone emulsionsAmodimethiconesDimethiconols,CopolyolsCombinations of these different typesThe level of conditioning from 2-in-1 shampoosis lower than that from stand-alone conditionersMany 2-in-1 products contain polyquats, whichmight be expected to increase conditioning ondamaged hair
Polyquat performance on treated hair may be nobetter than Dimethicone as a result of formation ofthe negatively charged polymer complexesin 2-in-1 shampoos Dimethicone Amodimethi Dimethicone cone copolyolscombing Similar Similar Lawconditioning Similar Similar Lawfoam volume reduced minimal effect minimal effect soluble dimethicone copolyols did not perform well
Preservativesinsure the microbiological integrityIf the product contains high concentrations of ethylalcohol (generally 20% or above), additionalpreservatives are not needed and the product isdescribed as self-preserving.Most of the preservatives used inpersonal care products are described inthe Cosmetic PreservativesEncyclopedia
Thickeners Cationic conditioning polymers can also act as thickeners Hydroxyethylcellulosea nonionic cellulose ether compatible with cationicsurfactants and stable over a wide pH rangethe most common thickening agent added toconditioning productsincreased viscosity, this material stabilizes viscosityover time
Polyamidescan be used to emulsify and thicken lotion orcream conditionersPolyacrylate-based thickeners such as carbopol in the past these thickeners have not alwaysbeen compatible with cationic surfactantsRecently, new thickeners based on polyacrylatechemistry have been commercialized to address thisissue.
Humectantspurpose is to attract moistureExamplespropylene glycolGlycerinHoneyChitosanhyaluronic acidNot expected to be very effective in rinse-off products.
EmulsifiersMost emulsifiers used in conditioners arenonionic including:Ethoxylated fatty alcoholsEthoxylated fatty estersEthoxylated sorbitan fatty esters.