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Glycol distearete issue in surfactant system
Hi all,
Has anybody experienced ethylene glycol distearate actually settling down over time? I have seen this with TiO2 when there’s no suspending agent, but not with EGDS. My bubble bath has 1% of EGDS, which was added at 75°C. Viscosity of around 2,000 cps and over a couple of days, there’s a white waxy substance at the bottom of the beaker.Thanks in advance for your help. -
14 Replies
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Ho joseg, for what purpose hace you Used EGDS in bubble bath ? If it is for Giving it a pearling effect then You may use EGMS.. It does not Settle down.. I think ( i am a Novice
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Yes, it will settle out of solution if it’s not in the proper formulation or the particles are too large. And @Chirag is right typically EGMS is what you use for the pearling effect.
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I second @Perry and @Chirag, I am using EGMS and it gives a beautiful pearly effect sans sedimentation, though acumen for formulating is needed even for the simplest formulas. Have learnt here only the importance of knock out and substitution techniques, and voila it gives a whole new dimension to formulating. Experienced it recently during dishwash and liquid laundry detergent formulations’ optimization.
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my two pennorth: the only time I’ve ever seen EGMS/EGDS pearls separate is in glass containers (notwithstanding formulas that were generally unfit for use); the fact that it could reliably be reproduced in glass, and was not all reproducable in any type of plastic container, strongly suggests that the interfacial properties of glass play a part in destabilising it
also, if EGMS/EGDS does separate it’ll rise to the top of the container rather than fall to the bottom and appear as sediment, since they both have a lower density than water
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@Bill_Toge I’m actually seeing a lot of sedimentation- almost like 1/4 of the jar at the bottom is a waxy pearlized concentrate…based on your insights, I’m thinking it’s not EGDS that settled, but the other surfactants…can that be possible? and why would it look pearlized? is it just like when you use too much stearic acid in a shave cream up to a point that it looks pearlized?
@Perry What do you mean by proper formulation? -
@joseg could you give a bit more idea about your formulation because making assumptions about formula outline isn’t gonna help.
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Sure, here’s my bubble bath formula…
Water q.s.Disodium EDTA 0.05%Propylene Glycol 1%Sodium Laureth Sulfate (28% active) 23.2%Cocamidopropyl Betaine 1.5%Cocamide DEA 3%EGDS 1%Fragrance 0.25%D&C Red #33 (0.1% aq.sol.) 0.25%Citric acid 0.1%Sodium chloride 0.8% -
this sounds more like you’ve not enough viscosity to keep the pearls from falling out
what viscometer, spindle and speed are you using to measure it?
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That is a lot of cocamide DEA. What’s the final pH? Personally, I would reduce the CDEA to 1.5% and remove the salt, adjust with citric acid to pH = 4.5, then increase the CAPB (which contains salt) until the required viscosity is reached. I don’t think there’s enough surfactant in there, either.
Begin by completely dissolving the EGDS in the (hot) SLES. Then blend in the rest but keep the temperature >70C. -
@joseg guess I don’t need to chip in as already @Bill_Toge & @Belassi have solved the issue. The only thing I would like to add is that complete information ex
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My viscosity is 3,100 cps LV4@60rpm … so EGDS will settle if not enough viscosity ? … I’ll make a batch with no salt adjustment and see how fast it settles compared to the adjusted one.
My final pH is 5.5 -
The question you have to ask, is, whether it is settling out or separating. My bet is the latter.
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It is separating together with some other surfactants … Because the amount of waxes at the bottom look like it’s more than 1% of the formula
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IF your viscosity is 2,000cps that is not thick enough to hold a pearl in suspension. Try increasing your Betain to about 5% (no additional salt yet) and see what you get. Then increase viscosity to about 5,000 or more. You can also try working with a little carbopol to help suspend. Doesn’t take much. Which carbopol will depend on your final pH
Did you heat your whole batch to 75c when you adeed EGDS? OR did you heat a small portion and then add that heated portion to a cold batch?
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