4.1-4.5 Polymers: sources, origins, properties, selection, impact of forces GapFill

Polymers are long chains of molecules commonly made from  tincrude oilcarbon dioxidewood.   This is sourced from countries all around the world, including Russia, UAE and   Saudi ArabiaFranceChinaUganda.   Recent developments have seen new polymers manufactured from  plantspaperwateracid, which are biodegradable. Polymers have different working properties and are, therefore, suited to a range of applications.   Polymers are divided into two main categories: thermoforming and  biodegradablesmartmodernthermosetting plastics.   Fluoroelastomer is a  smartthermoformingthermosettingbiodegradable polymer, typically used for sealing applications.   Polyester resin is a  thermoformingthermosettingmodernsmart plastic used as a sheet moulding compound.   Polyethylene terephthalate (PET) is a  smartmodernthermoformingthermosetting plastic typically seen in water bottles.   A tough, durable and flexible polymer,  PMMAPVCHIPSER, is commonly used for rainwater pipes and guttering.   Polymers have excellent resistance to  waterelectricityhardnessheat, making them an ideal choice of material to help protect against electrocution.   Sheet material such as HIPS is pre-coloured for use when  extrudinginjection mouldingvacuum forming3D printing, whereas coloured granules are introduced into the hopper when injection moulding to create coloured polymers.   ABS and acrylic are both polymers that have a  high hardnesslow tensile strengthhigh ductilitylow hardness.  Styrofoam and polystyrene are  poor heat insulatorshardtoughgood heat insulators.     A polymer is referred to as a self-finishing material as it has high-quality physical characteristics. Plastics are gauged by their density and  weightdurabilityvolumearea.   Urea formaldehyde is an example of a polymer that has a high  tensile strengthdurabilityweightdensity, making it an ideal material selection for fusing together wood.