Organic Polymers, Natural & Synthetic PDF

ORGANIC POLYMERS, NATURAL & SYNTHETIC  POLYMERS  Polymers are everywhere. Just look around. Your plastic water bottle. The silicone rubber tips on your phone’s earbuds. The nylon and polyester in your jacket or sneakers. The rubber in the tires on the fami...

ORGANIC POLYMERS, NATURAL & SYNTHETIC  POLYMERS  Polymers are everywhere. Just look around. Your plastic water bottle. The silicone rubber tips on your phone’s earbuds. The nylon and polyester in your jacket or sneakers. The rubber in the tires on the family car. Now take a look in the mirror. Many proteins in your body are polymers, too. Consider keratin (KAIR-uh-tin), the stuff your hair and nails are made from. Even the DNA in your cells is a polymer.  POLYMERS  By definition, polymers are large molecules made by bonding (chemically linking) a series of building blocks. The word polymer comes from the Greek words for “many parts.” Each of those parts is called as monomer (which in Greek means “one part”). Think of a polymer as a chain, with each of its links a monomer. Those monomers can be simple — just an atom or two or three — or they might be complicated ring-shaped structures containing a dozen or more atoms. Natural vs Synthetic Polymers  Synthetic polymers are derived from petroleum oil, and made by scientists and engineers. Examples of synthetic polymers include nylon, polyethylene, polyester, Teflon, and epoxy.  Natural polymers occur in nature and can be extracted. They are often water-based. Examples of naturally occurring polymers are silk, wool, DNA, cellulose and proteins. SYNTHETIC ADDITION POLYMERS  When monomer units add directly to one another, the result is an addition polymer. Each of these are derived from a monomer containing a carbon- carbon double bond. Upon polymerization, the double bond is converted to a single bond and successive monomer units add to one another.  Common Addition Polymers (See Common Addition Polymers.pdf) 1. POLYETHYLENE -The most familiar addition polymer is polyethylene, a solid derived from the monomer ethylene. USES: Bags, coatings, toys. These polymers are usually called plastics. where n is a very large number, of order of 2000  Common Addition Polymers Depending upon the condition of polymerization, the product may be:  BRANCHED polyethylene - symbol used is “LDPE #4”, indicating low density polyethylene. The smaller the number, the easier it is to recycle. These kind of structure produces a soft, flexible solid. Ex. Plastic bags at the vegetable counters of supermarkets  LINEAR polyethylene – is referred to in the recycling business as high density polyethylene, represented by the symbol “HDPE #2” on the bottom of a plastic bottle. These structure gives a polymer that approaches a crystalline material. It is used for bottles, toys and other semi-rigid objects.  Common Addition Polymers 2. POLYVINYL CHLORIDE - aka “PVC” is a stiff, rugged, cheap polymer. Vinyl chloride in contrast to ethylene, is an unsymmetrical molecule. We might refer to the CH2 group as the “head” of the molecule and the CHCl group as the “tail”  Common Addition Polymers Vinyl chloride molecules can add to one another in any of three ways to form: 1. A head-to-tail polymer, in which there is a Cl atom on every other C atom in the chain. 2. A head-to-head, tail-to-tail polymer, in which Cl atoms occur in pairs on adjacent C atoms in the chain. 3. A random polymer, similar arrangements are possible with polymers made from other unsymmetrical monomers.  Common Addition Polymers 3. TEFLON -where n is order of 10^4 to 10^5, is a versatile but expensive polymer ($10-20/kg). It is virtually impervious to chemical attack, even at high temperatures. The fluorine atoms form a protective shield around the central carbon chain.  SYNTHETIC CONDENSATION POLYMERS  A condensation reaction is one in which two molecules combine by splitting out a small molecule such as water.  A condensation polymer is formed where the molecule split out is most often water. In order to produce a condensation polymer, the monomers involved must have functional groups at both ends of the molecule. Most often these groups are NH2, OH, COOH.  The product formed are referred to as polyesters and polyamides.  SYNTHETIC CONDENSATION POLYMERS  POLYESTERS - Polyester is a category of polymers that contain the ester functional group in their main chain. The most important polyester is poly(ethylene terephthalate), commonly known as PET ( or “PETE 1” on plastic beverage bottles). Much of this is converted into fabric(trade name, Dacron) or magnetically coated film(aka Mylar).  SYNTHETIC CONDENSATION POLYMERS  POLYAMIDES - When a diamine(molecule containing two NH2 groups) reacts with a dicarboxylic acid(two COOH groups), a polyamide is formed. Ex. Nylon-66  CARBOHYDRATES  Comprises one of the three basic classes of foodstuffs: carbon, hydrogen and oxygen atoms. Their general formula Cn(H2O)m is the basis for their name. They can be classified as: 1.Monosaccharides 2.Disaccharides 3.Polysaccharides  CARBOHYDRATES 1.Monosaccharides -which cannot be broken down chemically to simpler carbohydrates. The most familiar monosaccharide contain either six carbon atoms per molecule (glucose, fructose, galactose,...) or five (ribose, arabinose,...) Glucose- (C6H12O6) aka “blood sugar” Fructose -is a natural simple sugar found in fruits, honey, and vegetables. Galactose- A sugar found in milk  CARBOHYDRATES 2. Disaccharides -which are dimers formed when two monosaccharide units combine with the elimination of H2O. Ex. Maltose/ C12H22O11– aka malt sugar, is a disacchride formed from two molecules of D-glucose. It is the basic molecule of starch. Sucrose -commonly known as “table sugar” or “cane sugar”, is a carbohydrate formed from the combination of glucose and fructose. Is the most abundant disaccharide and the major product of photosynthesis.  CARBOHYDRATES 3. Polysaccharides -aka “many sugars” which are condensation polymers, containing from several hundred to several thousand monosaccharide units. Cellulose and starch are the most common polysaccharide. Cellulose/ (C6H10O5)n - is one of many polymers found in nature. Wood, paper, and cotton all contain cellulose. Cellulose is an excellent fiber. Starch/ C27H48O20 - or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants as energy storage. It is the most common carbohydrate in human diets and is contained in large amounts in staple foods like potatoes, wheat, maize (corn), rice, and cassava.  PROTEINS -it is a natural polymer that make up about 15% by mass of our bodies. Fibrous proteins are the main components of hair, muscle ad skin. Other proteins found in body fluids transport oxygen, fats and other substances needed for metabolism. Insulin and vasopressin are hormones. Enzymes, which catalyze reactions in the body, are chiefly protein. In our digestive system, proteins are broken down into small molecules called α-amino acids.  PROTEINS α-amino acids -are monomer units of proteins. Amino acids are also called 'building blocks' of proteins.  Example 1: The addition polymer polyvinyl chloride (PVC) has the structure: a. Draw the structure of the monomer from which PVC is made. b. How many monomer units are in a PVC polymer that has a molar mass of Example 2: Consider propene: Sketch the structure of a head-to-tail polymer derived from it and sketch another structure assuming a head-to-head, tail-to-tail polymer. Example 3: Consider Teflon, the polymer made from the tetrafluoroethylene. a. Draw a portion of the Teflon molecule. b. Calculate the molar mass of a Teflon molecule that contains