chemicalmatt
Forum Replies Created
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You are not being ridiculous, you are the voice of reason! You should draw them that famous graph that exhibits the SPF value as asymptotic from number 45 onwards! A picture might be worth a thousand words here. Also, regardless of chemical sensititvity issues, do you think it is possible for a human test panel to validate that SPF value? Might be nigh impossible, and certainly VERY expensive. Good luck.
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vjay, if you can cite the source of the article you mention, that would be helpful. I have never heard or read of any mineral interactions with avobenzone; especially with a relatively inert one like TiO2. In any event, you may want to avail one of those singlet-state quenchers (esters) supplied by HallStar since sunlight itself degrades avobenzone somewhat rapidly - that much is definitely known!
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dmh0023, GMS will not form any pearlescence without emulsifying in water, so an anhydrous pearl isn’t going to happen that way. If you’ve got to have that pearly appearance, and your formula has no water, just add one of the many pretty mica blends (aka “glitter”) and be sure to suspend it well.
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Gustavo, my only experience with anionic styling resins is with the terpolymer Amphomer series from National Starch (now Akzo-Nobel?) and the ISP Gantrez series.of PMMA/VA copolymers (now Ashland?) These folks give you the equivalent weight and you plug in the correct MW for your alkaline agent, which I recommend be AMP or AMPD, also the degree of neutralization, and this gives you the various properties of film pliability - which you are obviously schooled in already. A helpful hint: use an alkyl amine (e.g. cocamidopropyl dimethylamine) to neutralize and you’ll get a nice firm hold with added humidity resistance, yet a nicer feel. Brazil, eh? Wish I was there - it’s minus 10C here in Chicago. Best of luck to you.
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Rahma, not to state the obvious, but mineral oil would be best. If you just have to go natural, however, coconut oil (92 mp), meadowfoamseed oil, jojoba oil, and olive oil have been shown to best penetrate the cuticle into the cortex, in decsending order of efficacy. The cortex is where you want to be. Look back into the SCC Journals (since 2004, if I remember) and you’ll find the TRI Princeton study article.