有机硅是一种合成聚合物，一种由较小的重复化学单元制成的材料，称为单体，以长链结合在一起。有机硅由硅 – 氧主链组成，“侧链”由与硅原子连接的氢和/或烃基组成。由于其主链不含碳，因此有机硅被认为是无机聚合物，其不同于许多有机聚合物，其主链由碳制成。硅氧烷主链中的硅 – 氧键是高度稳定的，比许多其他聚合物中存在的碳 – 碳键更强地结合在一起。因此，与常规的有机聚合物相比，硅氧烷更耐热。有机硅的侧链使聚合物具有疏水性，使其可用于可能需要排斥水的应用。侧链（通常由甲基组成）也使硅氧烷难以与其他化学物质反应并防止其粘附到许多表面上。可以通过改变附着在硅氧主链上的化学基团来调节这些性质。
Silicones are a type of synthetic polymer, a material made of smaller, repeating chemical units called monomers that are bonded together in long chains. Silicone consists of a silicon-oxygen backbone, with “sidechains” consisting of hydrogen and/or hydrocarbon groups attached to the silicon atoms. Because its backbone does not contain carbon, silicone is considered an inorganic polymer, which differs from the many organic polymers whose backbones are made of carbon. The silicon-oxygen bonds in the silicone backbone are highly stable, binding together more strongly than the carbon-carbon bonds present in many other polymers. Thus, silicone tends to be more resistant to heat than conventional, organic polymers. Silicone’s sidechains render the polymer hydrophobic, making it useful for applications that may require repelling water. The sidechains, which most commonly consist of methyl groups, also make it difficult for silicone to react with other chemicals and prevents it from sticking to many surfaces. These properties can be tuned by changing the chemical groups attached to the silicon-oxygen backbone.