chemicalmatt
Forum Replies Created
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@Abdullah you want to use (b) as you don’t need the CETAC in a shampoo formulation, it may even be detrimental, plus more amodimethicone activity.
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@Graillotion Lecithin (phosphatidylcholine mainly) is doing the heavy lifting in that combo. Behenyls alcohol and ester are merely the LLC builders for it. The only diff in using the behenyls is the softer sensorial and firmer consistency than if one used C12, 14, 16, 18 homologs.
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@kawina Many organic esters are miscible with IPA. Isononyl isnonanoate, isopropyl myristate, pentaerythrityl tetraisostearate, C12-15 alkyl benzoate, I could go on and on and on. Try one, check its miscibility in IPA and feel the joy.
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@David using SPDMA (Stearamidopropyl Dimethylamine, a tertiary amine) as the primary emulsifier as @EarthE has done here you will see a HUGE difference in viscosity when neutralizing with different organic acids as I noted. For simply reducing the pH of a cationic system comprising a cationic alkly quat or cationic polymer, not a great difference but citric is most likely to disrupt as he/she observed and for the reasons stated. Also, regarding EDTA or any other chelant in cationic hair conditioners, bear in mind those act as anti-redeposition agents primarily, preservative enhancers secondarily. In the case of hair conditioning you want to encourage deposition not discourage it, right? Thus I never add chelants to hair conditioners of any formulation medium.
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@Rockstargirl I’d be wary on factoring post-marketing royalty income. That gets real sticky for the brand and the accountants. They determine when profitability is reached, not you, and are unlikely to yield when making recurring payments. Unless you really have a novel product there that cannot be duplicated by one of us jamokes here in this forum, I’d get money upfront, and, yes, you are under-valuing your work. US$15,000 - $25,000 will be a better price, and you can work it out to be paid incrementally in quarterly payments to keep things nice for everyone.
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@ngarayeva001 citric acid is tribasic with three different pKa. Malic is dibasic, while lactic, glycolic are monobasic. When making an amine salt, monobasic will work without difficulty later. I’ve heard folks in this forum complaining when things go meshuginah when they add citric acid. Learn to use lactic acid instead.
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“the AHAS won’t perform” at a higher pH is a misconception. Yes they will they simply take longer to work on desquamation at pH 5.0 - 6.0. Safer and less irritating too. Also, that sodium stearate will not gel polyols & ethanol at a lower pH should have been obvious to the formulator, jus’ sayin’.
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Sometimes imitation is not a sincere form of flattery is the lesson here. Always question authority is the other. I have no answers but questions: Why the citric acid? Why so much PVP & PVP/VA? Why the concentrations calculated into second decimal place? Why 15 parts emulsifier blend to 24 parts oil phase? Why so much fragrance? I’d start over with the idea “less is more”.
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@stefarama all oils are occlusive to some degree, so he/she spoke the truth. Wash the hair thoroughly before dying with either oxidative or semipermanent hair dyes. Now, after dying the client’s hair, an oil treatment would be a good idea.
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I would not add xanthan gum or any other gum or polymer to a water-in-oil (inverse) emulsion such as this one. Easier: reduce propanediol to half that amount and most importantly HOMOGENIZE the pants off this when complete. Bear in mind all inverse-phase emulsions are intrinsically unstable , so don’t freak out if you see a little syneresis under stability testing or after six months RT.
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SPDMA will only contribute emulsification when used with an acid, and that is best done in sequence and with a weaker acid as @Abdullah suggests. Lactic, malic work far better than citric acid; l-arginine works best if you can afford it. Figure out the stoichiometry then add the weak acid to your water phase - after dispersing Polyquat-10 at RT first! - then begin heating to 85C. At 85C add the behenyl quat then the SPDMA, cetearyl alcohol, dimethicone and cool down slowly. I’d add ceteareth-20 or beheneth-20 also, but…that’s just me.
You are good to go, if you need more viscosity add salt (yes, NaCl) in dilute solution to the batch while still warm and in small additions. Oh yeah, and get rid of the EDTA, you don’t need it. Another preservative, on the other hand, would help. -
What “use” do you have in mind? Cationic emulsifier? Primary hair conditioner? That would be the determinant for starting point.
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@GabyD without concentrations - even rough ones - it will be impossible to assist here. You could begin with initial water content. My question: what is holding this together as a uniform, stable o/w emulsion? Something missing?
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Ethoxydiglycol: no problem. DMI is also stable at that pH but is best employed as a lipid carrier. Cost ratio of of DMI:ethoxydiglycol is ~ 15:1 so choose your penetrant.
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The ingredient you describe is better known here in the USA as CETAC, or cetrimonium chloride, and usually sold as a 30% solution. A useful alternative would be stearalkonium chloride (octadecyl trimethyl ammonium chloride) and sold as wither a 25% dispersion or 85% solid wax. Both are soluble in water at 75 - 80C. Few manufacturers exist for these “quats”, and I do not know the market you are in, but Stepan, Pilot-Mason, Lonza and Croda are distributed internationally.
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Fine the way it is, though a tad more of the PQ7 would not hurt and not add much cost either. Also @Abdullah is right about that NaCl. Should not take much.
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At only 5% in a waterborne emulsion product, petrolatum can only help not hurt. I like it a lot too.
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@ERP I cannot site any literature on hand, but I am pretty sure DHA lowers the extinction coefficient for organic sunscreens. If you are using TiO2 or ZnO it may not matter and you may be onto something there. I must say that the DHA is inducing melanin just as the sunscreen is inducing it at the same time. Is this redundant? Maybe that’s why nobody has done it?
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The reason you are seeing a higher viscosity with higher surfactant content is the amount of available water is decreasing. Keep going in this direction and you will soon have a jelly. However, should you change ratios of these three surfactants you would see higher or lower viscosities due to physical chemistry I am not going to spend time here explaining.
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Perry is correct in that BTMS renders CETAC redundant. The larger alkyl chain quat always displaces the lesser one, so delete. I know an ingredient you can obtain that will resolve the drying effect of post-chemical treated African hair: petrolatum. Cheap and totally effective. Also, @Mel55 you are wise to employ 350cst dimethicone. Good call there: that is the most versatile of all the dimethylpolysiloxane chain lengths for personal care.
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@MapX steers you well there @SlingerD in suggesting a rheology stabilizer, not only for stability but suspending that TiO2 otherwise it will eventually find its way to the bottom of your bottle. I’ll add though that what you observed is not so bad. The condensate was bound to happen inside a closed system heated by the sun and a little water exit post-freezing is not unusual. Add a little glycol either BG or PG and you may see that disappear.
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Man did this question go off the rails! To answer your original inquiry @ETcellphone: best use of either BG or PG is to “de-tack” stickier humectants and water-borne ingredients such as glycerin, sorbitol, xylitol, HYA and on and on… butylene glycol works best, but propylene glycol is less expensive. Both also decrease the freeze point which helps with freeze-thaw. As for these other uses, such as antimicrobial value: please ignore. As for renewable-grade propanediol: why waste money on that? Only 0.001% of the market cares where it came from.
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Better than either: acrylates copolymers, many of which are drop-ins already neutralized such as RapidGel EZ1 (3V Sigma). Also not all carbomers are same, you get varying properties and rheology outcomes and most formulators either don’t know this or forget. BTW, xanthan gum is anionic too, an aspect largely ignored. Make a xanthan gum dispersion then drop in CETAC or another cationic surfactant and see the mess you get. Xanthan is more electrolyte tolerant however. Can’t beat it there.
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I dunno’ ’bout all that, but @Zink should try it in skin-care. Lower your cost by using iQuat BTMC from Cosphatech (now Kimika LLC) or Maquat BTMC from Pilot-Mason, never from Croda (perhaps where @natzam44 went wrong?) Half the price for same material. Nice powdery after-feel - which admittedly can be achieved by other means - but as @Cafe33 mentions, emulsifies dimethicone like nothing else does.
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Comedogenicity is only a factor when the ingredient is used at high concentration, and isodecyl oleate is not a high comedogenic material, nor is cetyl alcohol. Go forth and formulate my friend.