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Siloxane
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<p>In <a href="/facts/Organosilicon_chemistry/JvUwzDQ4">organosilicon chemistry</a>, a siloxane is an <a href="/facts/Organic_compound/gqCNaN45">organic compound</a> containing a <a href="/facts/Functional_group/GXkSPsjM">functional group</a> of two <a href="/facts/Silicon/cgWx0hdr">silicon</a> atoms bound to an <a href="/facts/Oxygen/acyn6o8r">oxygen</a> atom: Si−O−Si. The <a href="/facts/Parent_structure/32I6krIn">parent</a> siloxanes include the <a href="/facts/Oligomer/v7oDY8zu">oligomeric</a> and <a href="/facts/Polymer/eF32E50K">polymeric</a> <a href="/facts/Hydride/v2rlBGMg">hydrides</a> with the formulae H[OSiH2]<i>n</i>OH and [OSiH2]<i>n</i>. Siloxanes also include <a href="/facts/Branching_(polymer_chemistry)/KYF9YA1j">branched compounds</a>, the defining feature of which is that each pair of silicon centres is separated by one oxygen atom. The siloxane functional group forms the <a href="/facts/Polymer_backbone/9Q3so597">backbone</a> of <a href="/facts/Silicone/4AX8YA5m">silicones</a> [−R2Si−O−SiR2−]<i>n</i>, the premier example of which is <a href="/facts/Polydimethylsiloxane/2lPYh00F">polydimethylsiloxane</a> (PDMS). The functional group R3SiO− (where the three Rs may be different) is called siloxy. Siloxanes are manmade and have many commercial and industrial applications because of the compounds’ <a href="/facts/Hydrophobe/Ifya0CXQ">hydrophobicity</a>, low <a href="/facts/Thermal_conductivity/qWnSG3nQ">thermal conductivity</a>, and high flexibility. </p>