Polymers  Elmhurst College
Addition Polymers Rubber  Chemistry Department
Condensation Polymers Silicone    Virtual ChemBook

Plastics that are Recycled 

 Recycle Code

 Abbreviation and Chemical Name of Plastic

  Types of Uses and  Examples

 1

PET - polyethylene terephthalate
 Clear, 2 liter beverage bottles

 2

HDPE - High density polyethylene
 Milk jugs, detergent bottles, some water bottles

 3

 PVC - Polyvinyl chloride
 Saran wrap, plastic drain pipe, shower curtains, some water bottles

 4

 LDPE - Low density polyethylene
 Plastic bags, garment bags, coffee can lids

 5

 PP - Polypropylene
 Aerosol can tops, rigid bottle caps, candy wrappers,
bottoms of bottles

 6

 PS - Polystyrene
 Hard clear plastic cups, foam cups, eating utensils,
deli food containers, some packing popcorn

 7

 Other
 Biodegradable, Some packing popcorn

Polymers

Introduction:

Polymers are long chain giant organic molecules are assembled from many smaller molecules called monomers. Polymers consist of many repeating monomer units in long chains. A polymer is analogous to a necklace made from many small beads (monomers).  

Another common name for many synthetic polymers is plastic which comes from the Greek word "plastikos", suitable for molding or shaping. Many objects in daily use from packing, wrapping, and building materials include half of all polymers synthesized. Other uses include textiles, TV's, CD's, automobiles, and many other all are made from polymers.

A quarter of the solid waste from homes is plastic materials - some of which may be recycled as shown in the table on the left.

 

 

 

Types of Polymers:

There are many types of polymers including synthetic and natural polymers.

Natural polymers are discussed in other web pages and include:
Proteins - silk, collagen, keratin.
Carbohydrates - cellulose, starch, glycogen
DNA - RNA

Other Natural polymers: Rubber (hydrocarbon base) and silicones (alternating silicon and oxygen).

 Classification of Polymers:
Homopolymers - consist of chains with identical bonding linkages to each monomer unit. This usually implies that the polymer is made from all identical monomer molecules.
These may be represented as : -[A-A-A-A-A-A]-
Copolymers - consist of chains with two or more linkages usually implying two or more different types of monomer units.
These may be represented as : -[A-B-A-B-A-B]-

 

Polymers are further classified by the reaction mode of polymerization, these include:

 

Addition Polymers - the monomer molecules bond to each other without the loss of any other atoms. Alkene monomers are the biggest groups of polymers in this class.

 

Condensation Polymers - usually two different monomer combine with the loss of a small molecule, usually water. Polyesters and polyamides (nylon) are in this class of polymers. Polyurethane Foam in graphic.

 

Classification based upon the physical property related to heating:

 

Thermoplastics - plastics that soften when heated and become firm again when cooled. This is the more popular type of plastic because the heating and cooling may be repeated.

 

Thermosets - plastics that soften when heated and can be molded, but harden permanently. They will decompose when reheated. An example is Bakelite, which is used in toasters, handles for pots and pans, dishes, electrical outlets and billiard balls.