Plastic - General

Question 1

What are plastics?

Answer 1

Plastics are made up of long chains of molecules which consist of various different combinations of atoms. The majority of long-chain molecules are hydrocarbons and others have been derived from natural resources.

Question 2

What are hydrocarbons?

Answer 2

Hydrocarbons are long-chain molecules which consist of hydrogen and carbon atoms in various combinations with other atoms.

Question 3

What does the term long-chain molecule mean?

Answer 3

• The main constituent part of a polymer. The long-chain molecule is made up of atoms.
• In the case of hydrocarbons these would be made up of hydrogen and carbon along with elements such as oxygen.

Question 4

What does the term polymer mean?

Answer 4

The term polymer, is the proper term for a plastic material.

Question 5

What are some sources of plastics?

Answer 5

Some sources of plastics are animal and vegetable by-products, casein and fossil fuels.

Question 6

What are animal and vegetable by-products?

Answer 6

Animal and vegetable by-products used in the manufacture of semi-synthetic polymers. Cellulose is a natural material occurring in plant fibres. This mixed with acetic acid to produce cellulose acetate allowing products such as OHP slides to be made.

Question 7

What is casein?

Answer 7

Casein is made by by-products of milk are used to create the polymer. The material is still used in the manufacture of buttons.

Question 8

What are fossil fuels?

Answer 8

Coal, oil and gas are fossil fuels, which are sources for a range of purely synthetic materials. Plastics gained through the process of thermal cracking. Synthetic plastics are therefore carbon-based and account for the majority of plastics used today.

Question 9

What are the three groups of plastics?

Answer 9

The three groups of plastics are thermoplastics, thermosetting plastics and elastomers.

Question 10

What are some general properties of plastics?

Answer 10

• They are good electrical and thermal insulators.
• They have a good strength to weight ratio. This doesn’t mean they are strong.
• Generally, they have good atmospheric and chemical corrosion resistance.

Question 11

What are biodegradable plastics?

Answer 11

Designed to be degradable under the right conditions, i.e. in a biologically rich environment.
-i.e. packaging, catering, medical and sanitary products

Question 12

Where are biodegradable materials from?

Answer 12

Majority derived from renewable raw materials, i.e. starch based polymers are produced from wheat, corn and potatoes and are used in the manufacture of capsules for medicines

Question 13

What is an example of another type of polymer derived from natural resources?

Answer 13

Polylactides (PLA), a transparent material with properties similar to polypropylene, so it can be used in similar ways.
-I.e. carrier bags, bottles, gardening products

Question 14

What is Biopol (PHA)?

Answer 14

A polymer made from natural cellulose, which can be used to make biodegradable packaging.
-i.e. wide ranging applications in medicine

Question 15

What is PHB?

Answer 15

Variations of this product are used in similar ways to polypropylene due similar properties.
-i.e. packaging

Question 16

What are oxo-degradable polymers?

Answer 16

Oxo-degradable have additives that promote short degradation time (less than five years), they help break the powder into a fine powder under the effects of heat, oxygen, moisture and even mechanical stress, making it more readily digestible by micro-organisms.
However, they are a expensive additive to incorporate into polymers.

Question 17

What is a photo-degradable polymer?

Answer 17

Break down when exposed to UV light making it more readily biodegradable.

Question 18

What are water-soluble polymers?

Answer 18

• Dissolve in warm water.

- i.e. detergent pouches for washing machine

Question 19

What are international symbols?

Answer 19

Modern plastic products, have a symbol that identifies the type of plastic material has been used. The international symbol for polymers is a recycle symbol with a number and letters imprinted underneath.

Question 20

What does the international symbol for polymers number 1 stand for and what are the common uses of it?

Answer 20

PETE, polyethylene terephthalate

-i.e. soft drinks and water bottles

Question 21

What does the international symbol for polymers number 2 stand for and what are the common uses of it?

Answer 21

HDPE, high density polyethylene

-i.e. food containers, bottles

Question 22

What does the international symbol for polymers number 3 stand for and what are the common uses of it?

Answer 22

PVC, polyvinyl chloride

-i.e. film, clear packaging, containers for non-food items

Question 23

What does the international symbol for polymers number 4 stand for and what are the common uses of it?

Answer 23

LDPE, low density up

-i.e. dry cleaning bags, carrier bags, squeezable bottles

Question 24

What does the international symbol for polymers number 5 stand for and what are the common uses of it?

Answer 24

PP, polypropylene

-i.e. margarine containers, medicine bottles, car parts, carpets, industrial fibres

Question 25

What does the international symbol for polymers number 6 stand for and what are the common uses of it?

Answer 25

PS, polystyrene

-i.e. meat trays, cups, plates, cutlery and compact disc sleeves

Question 26

What does the international symbol for polymers number 7 stand for and what are the common uses of it?

Answer 26

Other (any other polymer)

-i.e. reusable water bottles, telephone outer cases, computer parts, monitors, keyboard parts