reply to post by crisko
Im gonna say wrong on a number of accounts actually, but it isnt bees wax...and it is silica based which even organic sources ...creat kidney and gall
bladder ailments the least of which is stones!
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CAS number 63148-62-9 Y
Molecular formula (C2H6OSi)n
Density 965 kg m−3
Melting point N/A (vitrifies)
Boiling point N/A (vitrifies)
Y (what is this?) (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Polydimethylsiloxane (PDMS) belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones. PDMS is the most
widely used silicon-based organic polymer, and is particularly known for its unusual rheological (or flow) properties. Its applications range from
contact lenses and medical devices to elastomers; it is present, also, in shampoos (as dimethicone makes hair shiny and slippery), caulking,
lubricating oils, and heat-resistant tiles.
PDMS is optically clear, and, in general, is considered to be inert, non-toxic and non-flammable. It is occasionally called dimethicone and is one of
several types of silicone oil (polymerized siloxane).
2 Mechanical properties
3 Chemical compatibility
5 See also
The chemical formula for PDMS is CH3[Si(CH3)2O]nSi(CH3)3, where n is the number of repeating monomer [SiO(CH3)2] units. Industrial synthesis can begin
from dimethylchlorosilane and water by the following net reaction:
n Si(CH3)2Cl2 + n H2O → [Si(CH3)2O]n + 2n HCl
During polymerization, this reaction evolves potentially hazardous hydrogen chloride gas. For medical uses, a process was developed in which the
chlorine atoms in the silane precursor were replaced with acetate groups, so that the reaction product of the final curing process is nontoxic acetic
acid (vinegar). As a side-effect, the curing process is also much slower in this case. This is the chemistry used in consumer applications, such as
silicone caulk and adhesives.
Silane precursors with more acid-forming groups and fewer methyl groups, such as methyltrichlorosilane, can be used to introduce branches or
cross-links in the polymer chain. Under ideal conditions, each molecule of such a compound becomes a branch point. This can be used to produce hard
silicone resins. In a similar manner, precursors with three methyl groups can be used to limit molecular weight, since each such molecule has only one
reactive site and so forms the end of a siloxane chain.
The polymer is manufactured in multiple viscosities, ranging from a thin pourable liquid (when n is very low), to a thick rubbery semi-solid (when n
is very high). PDMS molecules have quite flexible polymer backbones (or chains) due to their siloxane linkages, which are analogous to the ether
linkages used to impart rubberiness to polyurethanes. Such flexible chains become loosely entangled when molecular weight is high, which results in
PDMS' unusually high level of viscoelasticity.