Polymers

Question 1

Name some polymer characteristics

Answer 1

Toughness
Elasticity
Insulation (thermal and elasticity)
UV resistance
Ability to be moulded
Resistance to chemicals and liquids
Melting points
Suitability for food packaging applications
Biodegradability
Recyclability
Self finishing
Ability to be combined with other polymers and/or additives

Question 2

Name some bio degradable plastics (bio plastics)

Answer 2

• corn starch polymer
• Potatopak
• Biopol
• PLA
• PHA
• Lactide
• Eco film

Question 3

Degradation occurs in the presence of ….

Answer 3

Light - photodegradable
Oxygen - (oxy-degradable)
Water - degradable

Question 4

What are the 2 bio plastics ?

Answer 4

Natural bio polymer , synthetic bio polymer

Question 5

Whats another word for thermoplastics ?

Answer 5

Thermoforming plastics

Question 6

What are the 3 types of plastics ?

Answer 6

Thermoplastics and thermosetting plastics and elastomers

Question 7

What are thermoplastics ?

Answer 7

Thermoplastics are plastics that will return to their original shape when heated till soft. They have a thing called “plastic memory”.

Question 8

At what temp do thermoplastics usually soften at ?

Answer 8

Thermoplastics generally soften at low temps ( as low as 100 degrees C ). This makes them inappropriate for products that involve relatively high temperatures. However thermoplastics are the most common type of plastic and are widely used for everyday products

Question 9

What are thermosetting plastic ?

Answer 9

They are very different from thermoplastics. When they are being formed a chemical reaction occurs causing them to create strong in their structure which means that they are permanently formed and cannot be softened by reheating. Because they do not soften, they can take very high temps often in excess of 400 degrees C. This makes thermosetting plastics very good for kitchen tools as they wont melt. Also they usually just start burning if you heat them enough

Question 10

What are elastomers ?

Answer 10

Elastomers have very good elasticity for e.g. they can be distorted under pressure but will return to their original shape when the pressure is removed. Elastomers have long chain molecules that can be considered to be coils - this is what causes them to be elastic. When the material is being distorted, the molecules distort, and then when the materials stop being distorted then they return to their original shape.

Question 11

What are the 2 types of elastomers ?

Answer 11

Thermosetting - natural or synthetic rubbers, cannot be recycled or reshaped, e.g, liquid silicon rubber

Thermoplastic - can be reheated and reshaped therefore recycled, can be manufactured using conventional equipment such as injection moulding or blow moulding

Question 12

Name some thermoplastics

Answer 12

• HDPE - high density polyethylene
• PMMA - Poly ( methyl methacrylate ) - acrylic
• HIPS - High impact polystyrene
• Nylon
• ABS - Acrylonitrile butadiene styrene
• LDPE - Low density polyethylene
• PVC - Polyvinyl Chloride

Question 13

Name some thermosetting plastics

Answer 13

• Urea Formaldehyde
• Epoxy resin
• Melamine formaldehyde
• Resin

Question 14

Name some elastomers

Answer 14

• Silicone
• Neoprene
• Buradiene Rubber
• Natural rubber - Polyisoprene

Question 15

What plastic are kids blow up swimming pools made out of ?

Answer 15

PVC - flexible polyvinyl chloride

Question 16

What are the car headlights made of ?

Answer 16

PMMA - acrylic

Question 17

What plastic are sockets made of ?

Answer 17

Urea Formaldehyde - UF

Question 18

What are gas canisters made out of ?

Answer 18

HDPE - High density polyethylene

Question 19

What type of plastic would a folder be made out of ? ( something like an art folder )

Answer 19

Polypropylene - PP
Or
PVC - Poly-vinyl Chloride

Question 20

What are polymer enhancements ?

Answer 20

Enhancing a polymers properties by using additives ( adder to a polymers stock form for a variety of reasons )

It is a way of improving a materials properties to better suit the requirements of the final product

Question 21

What do fillers do to a polymer ?

Answer 21

Fillers improve performance and / or reduce production costs and fillers can also improve the plastics impact resistance

Question 22

What are pigments ?

Answer 22

They are tiny particles that are mixed into the polymer in its molten state to give colour to the processed product

Question 23

What does the biodegradable plasticiser do ?

Answer 23

These make the polymer more flexible, softer and easier to break down, which means faster degradation time

Question 24

What are lubricants ( polymer enhancements ) ?

Answer 24

Lubricants as additives for polymers assist the movement of one object passing another object. Their primary role is to reduce friction, minimize wear and prevent overheating of parts.

Question 25

What are thermal antioxidants ?

Answer 25

Antioxidants protect plastics and other materials against thermally induced oxidation. This process can lead to a number of undesirable effects, including discoloration, changes in melt viscosity, and deterioration of mechanical properties. As a result, the useful life of the polymer or final article is limited.

In short it gives thermal protection to plastics