Plastics

OC58 identify everyday applications of plastics, and

Write out a list of Plastic items and write down why they are made of plastic

The word plastic is derived from the Greek πλαστικός (plastikos) meaning capable of being shaped or molded, from πλαστός (plastos) meaning molded. It refers to their malleability, or plasticity during manufacture, that allows them to be cast, pressed, or extruded into a variety of shapes—such as films, fibers, plates, tubes, bottles, boxes, and much more.

from wikipedia.org

History of Plastics

The production of semi-synthetic thermo-setting plastic materials arguably began with the production of vulcanised rubber in the USA and England in the 1840s. Independently, Alexander Parkes in England patented a plastic material based on cellulose nitrate in 1861, which indirectly led to the introduction of other semi-synthetic thermosetting plastics which were generally used in conjunction with an inert filler.

The first modern thermoplastics were all developed in the late 1920s or 1930s such as PVC, polystyrene, polythene and nylon.

The general structure of plastics was proposed by Hermann Staudinger in Germany in 1920 (he called polymers "macromolecules") but he was only awarded the Nobel Prize for Chemistry in 1953. Post-war work led to polycarbonate and polypropylene.

Name 10 things made from plastics. Write them down.

Could these things be made from other materials, go through your list and say yes / no

If yes then what other material could it be made from. Write this down too.

Go back over the list and describe what properties are required for the substance to fulfil its duty in each case

http://en.wikipedia.org/wiki/Plastics

OC58 ... understand that crude oil products are the raw material for the production of plastics

crude oil is the raw material for plastics

Pre Video questions

  1. What is oil formed from?
  2. What is the name of the process by which crude oil is separated?
  3. Name 3 different products that are made from crude oil .....
  4. ______ is the raw material for plastics

Crude oils vary in their composition, but generally range around

20% gasoline (petrol) and naphtha,

35% gas oil,

20% lube distillate,

20% residuum,

and 5% light gasoline.

Refinery processes turn low quality material into higher quality products.

Plastic manufacturers use processes like refiners, or purchase products to produce the chemicals that are used in synthesizing plastics.

Since crude oil contains many molecules, the industry breaks and builds molecules to fill the niche (the demands of the customer).

The other processes that are important are the reforming and alkylation processes.

Reforming converts naphthenes into aromatics like benzene, toluene, xylenes, and alkylbenzenes.

Taking longer molecules and making them into a few shorter molecules

Alkylation builds larger molecules from smaller molecules.

These Processes have their roles in the plastics industry.

By chemically cross-linking hydrocarbon chains you can get everything from synthetic rubber to nylon to the plastic in tupperware. Hydrocarbon chains are very versatile!

Advantages of using Plastic

1 Cheaper than glass / metal / stone / wood

2 Flexible

3 Plastic does not shatter (into small pieces)

4 Strong

5 Light (low density)

6 Can be moulded, or cut into shape

7 Does not corrode (rust or rot)

8 Does not conduct electricity

The Importance of plastics

In the United States alone, production of polymers as long ago as 1981 was more than 24 million metric tons, exceeding in volume the production of steel, and is the basis for industries that employs more than 3.5 million people.

So, what are polymers?

Polymers are very large molecules (macromolecules)

that are made up of smaller molecules (monomers)

These can be linked together in various ways, resulting in a range of what we call microstructures (e.g., linear chains, branched chains, densely interconnected networks, and so on).

Although natural polymers (cotton, wool, silk), have been used throughout recorded history, the first true synthetic polymers were produced relatively recently (in historical terms), at the start of the 20th century. In the decades that followed, however, an astonishing range of new synthetic materials were quickly produced by polymer chemists, revolutionizing some older industries, like those based on rubber, paint, and natural fibers, and creating new ones associated with the production of plastic goods. Polymers are also a crucial component of other advanced technologies, such as those essential to the electronics industry, where polymers are an integral part of the chip and printed circuit production process.

Leslie Allen,

Laboratory Chemist

Valero Refining Company

Natural rubber is a Natural Polymer, it comes from the rubber tree. These trees grow in Thailand, India and other similar climate countries. The trees are 'tapped' and a product known as Latex is collected

OC59 relate the properties of plastics to their use

Why do we use plastics ? (hidden text)

Cheap, Light, Durable, Easy to make into almost any shape, Safe, not corrodeable, Some are recyclable

Are all plastics the same? (hidden text)

No! What differences are there ?

What properties do they have?

pg 228 fill in a table similiar to the one below

LDPE

HDPE

Perspex

Heres the recycling list of plastics

http://www.wrap.org.uk/recycling_industry/information_by_material/plastics/types_of_plastic.html

Common plastics and uses

Polypropylene (PP) (5)

Food containers, appliances, car bumpers, plastic pressure pipe systems, school chairs

Polystyrene (PS) (6)

Packaging foam, food containers, disposable cups, plates, cutlery, CD and cassette boxes.

High impact polystyrene (HIPS)

Fridge liners, food packaging, vending cups.

Acrylonitrile butadiene styrene (ABS)

Electronic equipment cases (e.g., computer monitors, printers, keyboards), drainage pipe.

Polyethylene terephthalate (PET) (1)

Carbonated drinks bottles, jars, plastic film, microwavable packaging.

Polyester (PES)

Fibers, textiles.

Polyamides (PA) (Nylons)

Textile Fibers, toothbrush bristles, fishing line, under-the-hood car engine moldings.

Polyvinyl chloride (PVC)

Plumbing pipes and guttering, shower curtains, window frames, flooring, doors.

Polyurethanes (PU)

Cushioning foams, thermal insulation foams, surface coatings, printing rollers. (Currently 6th or 7th most commonly used plastic material, for instance the most commonly used plastic found in cars). Paints and Varnishes.

Polycarbonate (PC)

Compact discs, eyeglasses, riot shields, security windows, traffic lights, lenses.

Polyvinylidene chloride (PVDC) (Saran)

Food packaging (cling-film)

Polyethylene (PE)

Wide range of inexpensive uses including supermarket bags, plastic bottles.

Polycarbonate/Acrylonitrile Butadiene Styrene (PC/ABS)

A blend of PC and ABS that creates a stronger plastic. Used in car interior and exterior parts, and mobile phone bodies.

Special purpose plastics

Polymethyl methacrylate (PMMA)

Contact lenses, glazing (best known in this form by its various trade names around the world; e.g., Perspex, Oroglas, Plexiglas), aglets, fluorescent light diffusers, rear light covers for vehicles.

Polytetrafluoroethylene (PTFE)

Heat-resistant, low-friction coatings, used in things like non-stick surfaces for frying pans, plumber's tape and water slides. It is more commonly known as Teflon.

Polyetheretherketone (PEEK) (Polyetherketone)

Strong, chemical- and heat-resistant thermoplastic, biocompatibility allows for use in medical implant applications, aerospace moldings. One of the most expensive commercial polymers.

Polyetherimide (PEI) (Ultem)

A high temperature, chemically stable polymer that does not crystallize.

Phenolics (PF) or (phenol formaldehydes)

High modulus, relatively heat resistant, and excellent fire resistant polymer. Used for insulating parts in electrical fixtures, paper laminated products (e.g., Formica), thermally insulation foams. It is a thermosetting plastic, with the familiar trade name Bakelite, that can be molded by heat and pressure when mixed with a filler-like wood flour or can be cast in its unfilled liquid form or cast as foam (e.g., Oasis). Problems include the probability of moldings naturally being dark colors (red, green, brown), and as thermoset it is difficult to recycle.

Urea-formaldehyde (UF)

One of the aminoplasts and used as a multi-colorable alternative to phenolics. Used as a wood adhesive (for plywood, chipboard, hardboard) and electrical switch housings.

Melamine formaldehyde (MF)

One of the aminoplasts, and used as a multi-colorable alternative to phenolics, for instance in moldings (e.g., break-resistance alternatives to ceramic cups, plates and bowls for children) and the decorated top surface layer of the paper laminates (e.g., Formica).

Polylactic acid (PLA)

A biodegradable, thermoplastic found converted into a variety of aliphatic polyesters derived from lactic acid which in turn can be made by fermentation of various agricultural products such as corn starch, once made from dairy products.

Catalysts

Catalysts are compounds that alter the rate of reaction,

(change the amount of time a reaction takes).

So if you have a slow reaction that is safe you may try to use a cataylst to speed up the reaction, these are known as accelerants If you have a fast reaction that causes a dangerous chemical to be given off then you would use an Inhibitor.

Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. That is the same mass of catalyst remains at the end as was at the start because none of it is used up. The catalyst may participate in multiple chemical transformations.

Catalysts that speed the reaction are called positive catalysts accelerants. Catalysts that slow down the reaction are called negative catalysts or inhibitors.

A catalyst you should know is Manganese Dioxide this is used when we make O2 from Hydrogen Peroxide (H2O2)

For demonstration of cataylsts,

  1. take a sugar cube, try to light it.
  2. take some ash from burned paper try to burn it
  3. rub some ash into a corner of the sugar cube and try to light it
  4. Make some judgements on what you observed

Catalytic converters are used in cars to remove harmful chemicals from their exhausts fumes, a picture of one here

What else do you think might alter the rate of reactions?

Particle Size Temperature

OC60 describe and discuss the impact of nonbiodegradable plastics on the environment

non-biodegradable plastics and their contribution to pollution

discuss the possibilities of using biodegradeable plastics

Plastarch material

Biodegradable and heat resistant, thermoplastic composed of modified corn starch.

Biodegradable plastics

Starch is a naturally occurring polymer, that is found in many foods. This starch can also be used to make bags and wrapping material, the benefit comes from the fact that the starch is natural and therefore can be broken down by nature.

PolyLactic acid is a polymer of lactic acid from dairy products and can be used instead of PET

PHA, polyhydroxxyalkanocke polymer is made by bacteria and can be used for making plastic bottles and credit card like items

These are ways that we will survive if all the crude oil gets used up.

PVA Poly Vinal Alcohol

Making natural plastics.

1 tablespoon of vinegar

1/3 l or 33 cl whole milk.

Warm the milk.

Add the vinegar,

the amounts are approximate.

Strain the mixture keeping the solid curds.

Dry them on kitchen paper and mould them.

If left to dry in a warm place they become very solid and hard.

They can then be painted.

Food colouring can be added to make different coloured shapes.

Why drink bottled water .... here are 6 reasons why not!

http://www.noomii.com/blog/3006-stop-consumption-bottled-water

Test yourself at

http://www.sciencequiz.net/jcscience/jcchemistry/fossilplastic/fossilplastic.htm