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Natural Polymers. By: Jordan Storey & Tomy Nicholson. Origin of the word polymer. The word polymer originates from the two Greek words: “poly” and “ meros ”. “Poly” translates to many, and “ meros ” translates to parts. Therefore, a polymer is a molecule that is composed of multiple parts.
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Natural Polymers By: Jordan Storey & Tomy Nicholson
Origin of the word polymer • The word polymer originates from the two Greek words: “poly” and “meros”. • “Poly” translates to many, and “meros” translates to parts. • Therefore, a polymer is a molecule that is composed of multiple parts.
What is a Natural Polymer? • A polymer is a long chain of thousands of identical “unit molecules” called monomers. • A natural polymer is a polymer that is found in nature and is not man made all natural or organic polymers come from living organisms.
Key terms to understanding polymers • Monomer: A simple molecule that joins with others to create a long complex chain called a polymer. • Polymerization: The process of producing a polymer from monomers. (Bonding). • AdditionReaction: a reaction that creates polymers in which an unsaturated monomer becomes saturated. (It loses the double bond). (This will be explained in the next slide). • Condensation Reaction: polymers are formed by monomers who bond front to end. The product of this reaction is usually water. (This will be elaborated later in the presentation). • Functional Group: a specific arrangement of atoms that characterise chemical reaction in organic chemistry. (This is a way of classifying organic compounds).
Definition Addition Reaction Explanation Photos/Diagram • This diagram shows two ethenemonomers, that form one polythene polymer. This is an addition reaction. • (*Notice the double bonds are lost to continue the polymer chain).
chemists who contributed to the science of natural polymers • Now we will discuss three chemists responsible for the advancement of chemistry involving polymers.
Thomas Graham • In 1861 Thomas Graham, a British Chemist realized that organic compounds such as starch and cellulose would not pass through fine filters, and that they could not be purified into crystalline form. He believed the organization of the atoms in these compounds to be completely different from any other. Thomas Graham
Herman Staudinger • In 1920 Herman Staudinger researched polymers. He determined that polymers are composed of long chain molecules. These molecules are either identical or closely related. This discovery became the fundamental description of a polymer’s form. He later became the first polymer chemist to win a Nobel Prize. Herman Staudinger
Kurt Meyer & Herman Mark • In 1928 Kurt Meyer and Herman Mark demonstrated the existence of polymers by examining their crystalline structures with x-rays. These findings helped Staudinger’s findings have more credibility. Herman Mark
Where Can they be found? • Since natural polymers are natural they are found in nature. The human body, plants, food, and many other living beings.
Examples • On the following slides are some examples of natural polymers.
Starch • Starch- is a polymer formed of thousands of glucose monomers. As it is being formed it produces water molecules. Starch is a carbohydrate and is therefore found in a variety of foods such as cereal grains and potatoes.
Cellulose • Cellulose- is the most common natural, (organic) compound on earth. This polymer is the base of which plants are made of, (their stems, leaves and the trunks of trees to name a few examples. It is also composed mainly of glucose, However the difference is made by the bonding arrangement.
Proteins or Polypeptides • Proteins- a common example would be DNA. They are formed by the bonding of amino acids. Proteins are linked by peptide bonds, which will be discussed later in the presentation.
Bonding Examples • There are different types of bonds found in polymers in the following slides we will look at a few examples.
Peptide Bonds • Peptide Bonds are formed by the joining of a large quantity of amino acid units. The product of peptide bonds are called polypeptides. All protein molecules are polypeptides. This reaction produces water as a by-product and is therefore a condensation reaction.
Disulfide Bonds • This bond is when two sulfur atoms, from two monomers that bond together. • In this case hydrogen is the product, in addition to the polymer.
Hydrogen Bonds • These bonds occur between the O, (oxygen) and H, (hydrogen) molecules of two monomers.
Salt Bridge • Negative charged side chains attract to positive charged side chains. (See the diagram below).
Info on Amino Acids Bonding • Amino acids are the monomers in protein polymers. • All amino acids except one of the twenty have the same general form. • Amino acids have side chains that determine their form.
How to draw the structure • Since we know that polymers can contain thousands of monomers, this becomes a seemingly overwhelming task. • However when drawing the structure or writing the formula we do not focus on the entire polymer. But only on a small part of it. This is the part that is repeated throughout the polymer.
Structure • Draw the monomer structure. • Put the brackets around the monomer. (Also notice that the monomer loses the double bond). • Place horizontal lines on the brackets, (this symbolizes that the monomer is bonded to other identical monomers). • Place either a subscript n or the number of polymer links, (if known) outside the brackets.
Naming • The naming for polymers is rather simple, they follow the same general rule. • Poly(name of monomer) • Certain polymers have more than one monomer, but it follows the same rule. • (There are some exceptions to this rule, some polymers have more than one name).
What is Vinyl • Vinyl is an ethene which has 3 hydrogen atoms and 1 bond ready to take on a functional group, (substituent).
How to Write the formula • When writing the formula: • 1. Identify the monomer. • 2.Use brackets with bonds coming off each side. • 3. Put n outside of brackets, (as a subscript), or the number of monomers, (if known). • Example: (See next slide)
Interesting Facts about natural polymers • The human body has approximately 100 000 different proteins. All of these proteins are made of only 20 different amino acids, (which are polymers). • Polyisoprene, is a polymer harvested from tropical plants. An example would be the rubber tree, (Heveabrasiliensis). The sap from the tree is more commonly known as latex. Polyisoprene
Great Resources • Great Document: http://preparatorychemistry.com/Bishop_Book_17_eBook.pdf • Great Website: http://www.britannica.com/EBchecked/topic/468696/polymer • Great Text Book: General Chemistry Principles & Modern Applications Sixth Edition-Petrucci Harwood-ISBN 0-02-394931-7 • Great Video: http://www.youtube.com/watch?v=KAruoKzTwfU
Videos • http://www.youtube.com/watch?v=IkT7cxDsstI –A world Without Natural Polymers (3:21) • http://www.youtube.com/watch?v=KAruoKzTwfU –General Explanation (3:11)
