Polymers

Question 1

Thermoforming polymers definition

Answer 1

flexible when heated as their physical structure is polymer chains loosely entangled with very few cross links, allowing them to slide past each other when heated

Question 2

Examples of thermoforming polymers

Answer 2

polypropylene (PP), acrylic, high density polyethylene (HDPE), high impact polystyrene (HIPS), polyethylene terephthalate (PET), polyvinyl chloride (PVC)

Question 3

Properties and uses of polypropylene (PP)

Answer 3

flexible, tough, lightweight, food safe, kitchen and medical products, rope

Question 4

Properties and uses of acrylic

Answer 4

tough but brittle when thin, easily scratched, formed and bonded

Question 5

Properties and uses of high density polyethylene (HDPE)

Answer 5

lightweight, rip and chemical resistant, milk bottles, pipes, crates, wheelie bins

Question 6

Properties and uses of high impact polystyrene (HIPS)

Answer 6

flexible, impact resistant, lightweight, can be food safe, used for vacuum forming, yogurt pits, vacuum formed products

Question 7

Properties and uses of polyethylene terephthalate (PET)

Answer 7

blow moulded, chemically resistant, fully recyclable, drinks bottles, food containers, yarn

Question 8

Properties and uses of polyvinyl chloride (PVC)

Answer 8

flexible, easily extruded, tough, resistant to chemicals, raincoats, pipes, electrical tape

Question 9

Thermosetting polymer definition

Answer 9

they undergo a chemical change so once they are formed they cannot be reformed, they are resistant to higher temperatures and tend to burn rather than melt, rigid cross links that set when heated, more brittle and provide a good insulation

Question 10

Examples of thermosetting polymers

Answer 10

polyester resin (PR), epoxy resin (ER), urea formaldehyde (UF), phenol formaldehyde (PF), melamine formaldehyde (MF)

Question 11

Properties and uses of polyester resin (PR)

Answer 11

good electrical insulator, hard, tough when mixed with glass, encapsulation, boat hulls as glass reinforced plastic

Question 12

Properties and uses of epoxy resin (ER)

Answer 12

good strength to weight ratio, good electrical insulator, heat resistant, bonding waterproof coatings, electronic circuit boards

Question 13

Properties and uses of urea formaldehyde (UF)

Answer 13

high tensile strength, heat resistant, good electrical insulator, hard, brittle, easily injection moulded, adhesives for bonding particle boards, electrical casings

Question 14

Properties and uses of phenol formaldehyde (PF)

Answer 14

heat resistant, good electrical insulator, heat resistant handles, electrical components, snooker balls

Question 15

Properties and uses of melamine formaldehyde (MF)

Answer 15

lightweight, hard but brittle, worktops, surfaces and some kitchenware