Dimethicone    (aka Linear Polydimethylsiloxanes; Linear PDMS; Dimethyl silicone)
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This is the name for a group of silicones. The heaviest of all silicones used for hair care, they provide the most smoothing effect, but is hardest to wash out. Also might be considered too heavy for less curly hair [Beauty Brains pg 38 and provided link]. Conditions by preventing water loss. Also used to keep a product from foaming. Used in a huge amount of products, from hair conditioners to makeup [Gottschalck pg 562]. Gives a velvety feel. This does not evaporate [Schueller pgs 174-178]. Dimethicones are considered nonirritating to the skin and eyes. The different grades of Dimethicones come in different thicknesses, ranging from ones that will quickly evaporate (Hexamethyldisiloxane), to the consistency of honey, to those thicker than silly putty [Schueller pgs 174-178, Hunting (Conditioning) pgs181-182]. Though they are thick, they still allow the surface they are on to "breathe", meaning that water evaporation still occurs through it, so they aren't very moisturizing [Hunting (Conditioning) pg 181-182]. Makes product slippery so comb (or Denman) glides more easily through your curls. —T This is in one of my favorite, go to conditioners that I've been using for well over ten years. It has not caused any problems as far as conditioning and defining my hair. That's why I'm calling it a

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See also: Silicone
Source(s): Gottschalck Beauty Brains Schueller Hunting http://www.theBeautyBrains.com http://clicks.aweber.com/y/ct/?l=DULo7&m=IsGc6lRxjJPguz&b=WQE7LVCT7u7x1K1bpcFv9A