What materials are used to make airplane windows?

It depends on what airplane and which window to which you refer. Many general aviation airplanes use plexiglas or similar materials. Jet airliner cabin windows are usually acrylic, and consist of three layers of material for redundancy and safety. Cockpit windows (which run the risk of bird strikes, hail, etc.) are made of multiple layers of glass and plastic, bonded together and with a heating element inside them to prevent ice from obscuring the view. Usually they are also coated on the outside with a material to help shed rain in flight (as the substance that used to be sprayed on them was banned about 15 years ago as an ozone-depleting substance). For more information, please check out the following website: http://corporateportal.ppg.com/NA/Aerospace/Transparencies/CommercialAviation/Trans_CommAviation.htm and select the download for the 707/727/737 in .pdf format. Page 2 of the download shows a typical cross-section of a cockpit windshield