chemicalmatt
Forum Replies Created
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@Stivtoo Inconsistent results: it would appear this is not a mixing/processing issue but a chemistry problem. Without knowing exact concentrations, I’ll posit that you are relying solely on the BTMS as emulsifier, the sorbitan stearate is only a builder, so you’ve reached the limit of oil load capacity. I’ll bet if you added 1.0% ceteareth-20 or ceteareth-25 to your oil phase this will come together, but that is only a guess. BTW, if you add BTMS directly into water phase at 80 - 85C, melt & mix, then the ceteareth-20, then the oil constituents in order you can have a one-pot mix.
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Silica! Works like a charm.
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MAtching that silicone elastomer’s sensorial property is a tough task. Other than the perflourethers that one is the best for “velvet”. If you can get hold of esters readily, try making an ester cascade effect with two or more. Cetyl palmitate/trimethylolpropane triisostearate/isononyl isononanoate for a start will provide a satiny cushion.
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Good for you @Mondonna, been there and done that myself many years back in the lean days. Without Amazon or Ebay I took a trip to the aquarium supply shop to get the lamp. Anyway, you want to test at 285 - 340nm for UV-B and far UV-A where most of the action is. Most blacklights emit nearer to 285nm if I remember.
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My choice would be cetyl alcohol alone in most formulations. Where you have GMS, stearic acid, sucrose stearate, etc. etc. mainly C18 moities, the cetearyl would behave better.
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I do not think CMIT/MIT will deposit, especially at 10ppm. Polyquats must form coacervates with the surfactants and those coacervates must bring with them only whatever they can associate with, dimethicone being the most dependable.
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@Abdullah That mass ratio is the ideal (“classic”) ratio for building cleansing products like shampoos and body washes. Floor cleaners, laundry detergents, hard surface cleaners are a different story. The “classic” viscosity builder is an alkanolamide (cocoamide DEA in the old days) at the “classic” ratio 4:2:1 anionic: amphoteric: alkanolamide. I’ve found substituting coacoamidopropylamine oxide or lauramidopropylamine oxide for the amide results in good viscosity & foam build but gains better deposition of the polyquaternium/dimethicone (or guar HPTC if you’re one of those people) upon rinsing.
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@ketchito is onto the solution here, in two parts, but let me add some clarification. Cationic emulsions such as yours @Stivtoo require low shear and a long cooling gradient to form lamellar liquid crystal matrices. If the only tool you have is a homogenizer, you will see inconsistent results like you have, and not much to do about it. I would apply the homogenizer for only 5 minutes (@Abdullah is right, 30 minutes unnecessary) at 75C, then begin cooling SLOWLY while mixing with a low shear Lightnin’ mixer at low-moderate speed. Once you get to 40 -45C and thickened you can zap it again with the homogenizer to smooth out even more. @Gordof is correct here: what you see is inversion, your emulsion doesn’t know what it wants to be. Slow cool at low shear and it will be consistent each time.
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There are different ratios of C16:C18 for these. The 30:70 is more generally used but I’ve always preferred the 50:50 material finding the extra cetyl provides easier lamellar liquid crystal formation. Proctor & Gamble figured all this out many years ago when they had the fatty alcohol market homogenized, and P&G still makes and uses a boatload of material every day.
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Agree with @Paprik here @GeorgeBenson : charge density, pKa and ratio is not the main consideration. The mass ratio is however, and the “classic” ratio of anionic: amphoteric is 2:1 based on solids. If you are formulating a conditioning shampoo with cationic polymers, then increase ampho slightly and never use a highly charged anionic (i.e. sulfates, phosphates). Another helpful hint from an Old School formulator (that would be moi): use an amine oxide as builder and your dilution-deposition is even better.
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50C is very high as @Microformulation (Mark) says, @MsCheddar. I’ve been told that 50C temp for accelerated stability arises from an ASTM method used in pharma and unfortunately adapted by personal care formulators. Mark is right, 40C is fine and I usually run at 43C / 65% RH, no higher.
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Upon rinsing the lather from hair, thus the term “dilution-deposition” from the coacervate system.
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@GeorgeBenson the viscosity will peak at pH 6.5 - 7.0, the yield value (suspension factor) will be at maximum in that range too. This is a 30% solution so depending on what surfactants or electrolytes you have in the formula, and final viscosity, start at 4.00% (1.20% solids) and see what happens. It works best to add to water first, then add your surfactants, any alkali you may be using, then adjust pH at end. If you have a high pH surfactant system (decyl glucoside comes to mind) you may drop in later, but that is not advised. Also, like all acrylic rheology modifiers, go easy on the amphoteric surfactants. These are Zwitterions. 10% CAPB (30% soln.) will be fine.
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Your confusion is warranted. If the x-axis values are %Transmission @ 600nm (yellow-red part of spectrum) how did the analyst gain a transmission HIGHER than 100% with their cationic polymer? Impossible. Other than that absurdity, it shows their Polyquat-74 flocced nearly out of solution at a 2:1 dilution-deposition ratio with water while at a 4:1 ratio Polyqaut-10 (my personal fave) deposited onto substrate better than theirs and guarHPTC deposited even better at a 6:1 dilution-deposition. My conclusion: try not to spend too much time under the shower head when rinsing that 2-in-1 conditioning shampoo off your hair.
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@Pharma :smiley: funny! I can read the advert now: ” from the ancient waters of Lake Michigan where Potawatomi natives swam and frolicked with pristine sturgeons..”.
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IF you are formulating with urea, DO NOT premix it, there is no need, it readily dissolves and is a weak electrolyte at best . Always add it directly to the batch during the cooling phase after heating/combining phases in an o/w emulsion for the same reason you state: it dissolves in water endothermically and will cool your batch as it dissolves. No ethanol is needed but a buffer is. Use lactic acid/sodium lactate at pH 5.5 - 6.0 or add rice starch, the more natural means of stabilizing urea.
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@Stanley Drafting SDS is as much an art as a science. As long as there are no ingredients listed as hazardous in TSCA you may not need to list them in that section - leave it blank. I generally list the chief components with their CAS# just as a courtesy to interested parties. I find that makes them feel better about the safety of the product. As for Section 1, you must name the product as stated on the label, the responsible party for commercial distribution (e.g. the customer-distributor on the label) and of course an address and phone# to contact. Inform your private label customer and ask them for the phone# to call - they might tell you to list yours. Describe the product as “non-hazardous mixture in an aqueous dispersion” or something generic as @CedarS
suggests. Someday I’ll have to lead a seminar on this topic. -
Brylcreme! “A little dab’ll do ya!” Thanks, Phil.
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@Abdullah you are right: a little GMS helps build lamellar liquid crystal network favorable to viscosity and stability build. @Graillotion you are also on the right path there, MM or CP (nearly same thing) will add a softer sensorial finish. More esters, less fatty alcohol is my advice. As for using behenyl OH as builder, you are just as well off with cetearyl alcohol, and the cetearyl costs less. Behenyl OH does contribute the softer sensorial though.
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I’m with @Mondonna on the mallow root extract in hair-care. I was skeptical when a client insisted on it, then tried it myself and said to self “why I’ll be, this is like a natural answer to behenyl quats, my hair is soft as silk.” Also algae does even better! After taking a late summer swim in Lake Michigan (algae is highest then) my hair is softer than it is all year. Now, how to extract that and sell it ???
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Bria Research Labs in Chicagoland performs claims testing par excellence at fair price. Mark Chandler’s ACTS Testing in Delaware does excellent sensorial testing at very fair prices also.
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Perry is on the mark - again - in his summation. Behenyl quat chloride (BTMC) is less expensive than the methosulfate by many $$$, and it is the alkyl quaternary that does the heavy lifting, not the anion. BTMC is the better, cheaper emulsifier too, especially when you use the 85% wax (dissolved into the water at 85 - 90C.) As for efficacy, the behenyl quats lend a softness to hair and skin substantially better than the lower homologs STEARAC, CETAC. Summing up: friends, don’t let friends use BTMS-25 or 50 when BTMC 85% can be had.
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Actually @GeorgeBenson & @AMS, Perry had it right the first time and…err..the third time(I dunno…I lost count here). ALWAYS add PQ-10 or cationic guar or any cellulosic to COLD (RT) water first, use high-speed mixing to hydrate, then proceed only when that is 100% accomplished. The article mentions “adding to surfactant systems” in the global sense, not the order of addition sense. It also fails to mention critical elements of dilution-deposition activity with these cationic polymers. Add an amphoteric surfactant to the batch immediately after the cationic gum hydrates, then a nonionic and the anionic last. This hydrotrope/cationic matrix complexes with the anionic vesicle aiding polymer deposition. MINIMIZE or AVOID salt addition, why we use low-salt amhoterics instead of CAPB or a sultaine. Salt intereferes with deposition. If using a low MW PQ-10 like the 400 series, pair with a high MW dimethicone (350 cst minimum). Counter-intuitive but that’s what works.
As for the alkali-gel trick (hack?) with guar HPTC mentioned by @ketchito
allow a good 30 minutes high-speed mixing to pass before adding and don’t add much. This hack also works for pure guar and HP guars too. Just make sure not to use sodium borate or…well…you’ll find out why. Think rubber ball. -
Depending on your gauge for “effectiveness”, triethyl citrate does reduce body odor to the extent it fixates, preventing it from exuding as a volatile (what we call “stank”). Compared to AL-Zr salts: weaker for sure but then these are drug actives here in the USA. As for your wax issue: sounds like it is creaming with the underarm sweat and its salts. Yikes! Better reach for the butylene glycol.
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That is really low Aw, so if you use any preservative at all it wouldn’t need much. Dr. Phil?