Core Chemistry AQA Section 5

Making Polymers from Alkenes -Plastics are made from large molecules called polymers, made from small molecules joined together. The small molecules used to make polymers are called monomers, polymerisation is the reaction to make a polymer.  -Ethene molecules can join to form poly(ethene) called polythene. In the polymerisationg reaction double bonds of ethene become single bonds and ethene molecules join together in long chains.  -Alkenes can polymerise in a similar way, e.g propene can form poly (propene). -Many plastic bags, bottles and containers and toys are made from alkenes.    New and Useful Polymers -Scientists can use materials to design new polymrs to make materials with special properties for particular uses. Many of these materials are used for packaging, clothing and medical applications.  -New polymer materials for dental fillings have been developed to replace filling that contain mercuy, light sensitive polymers are used in sticking plaster to cover wounds so plasters can be easily removed. Hydrogels are polymers that can trap water and have many uses that include dressing wounds.  -Shape memory polymers change back to their original shape when the temperature or other conditions are changed, for example smart polymer is a material used for stitching wounfs that changes shape when heated to body temperatures.  -The fibres used to make fabrics can be…