: an isomer that is a stereoisomer of a compound having two or more chiral centers and that is not a mirror image of another stereoisomer of the same compound â
A compact disc is a deceptively simple looking device considering the technology required to make it. 1  CDs consist of three layers of materials: 2  A base layer made of a polycarbonate plastic. 3  A thin layer of aluminum coating over the polycarbonate plastic. 4  A clear protective acrylic coating over the aluminum layer.
Most plastic glasses are made of zyl (also called zylonite, acetate and cellulose acetate) or propionate. Other materials used in plastic frames include polyamide, nylon, polycarbonate, carbon and Optyl (a brand of epoxy resin). Propionate, polyamide, nylon and Optyl frames are all considered hypoallergenic. â G.W.