Terms in this set (14)

Common in industry and biological systems.

Two monomers react to produce a polymer and another small molecule, usually water but can be NH3 or HCl. The formation of the small molecule is from the functional groups of two different monomer molecules. The small molecule is said to be 'condensed out' of the reaction. The monomer molecules bond at the site where atoms are removed from their functional groups.

To form a condensation polymer, the monomer molecules must each have at least two functional groups, one on each end ie on each end of one molecule there is an -OH and on each end of the other molecule is a -COOH.

NOTE: AN ESTERIFICATION REACTION THAT IS REPEATED TO FORM A POLYMER IS ALSO CONSIDERED A RESULT OF CONDENSATION POLYMERIZATION, EVEN THOUGH EITHER END DOES NOT HAVE THE SAME MOLECULE

To determine the product of this reaction, look for at the carboxylic acid and alcohol in the two reactants. Where the OH at the end of a -COOH meets with the HO- of the alcohol in the next molecule, that is the water that will escape. Remove this and chain everything together.

ie. HO-CH2-CH2-OH + HOOC-CH2-CH2-COOH + HO-CH2-CH2-OH ->
OC-CH2-CH2-CO-OCH2-CH2O-OC-CH2-CH2-COO-OCH2...etc...

Lipids (fats and oils)
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Formed via esterification reactions between glycerol (propane-1,2,3-triol) and fatty acids (long-chain carboxylic acids). The largest molecule formed is a tri-ester and water (like esterification would) but the ester has a chain of three like a polymer.

'Natural' polyester:

glycerol + saturated fatty acid -> saturated fat + water
glycerol + unsaturated fatty acid -> unsaturated fat + water

Polyester
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A carboxylic acid reacts with an alcohol in an esterification reaction to make a water molecule and a single ester molecule. The two reactant molecules are linked together in a single ester molecule. The esterification reaction is repeated to form many esters in a long chain called a polyester. Ester linkages are formed in the resulting polymer, end to end between alternating acid and alcohol molecules.

Synthetic polyester:

dicarboxylic acid + polyalcohol -> polyester + water

Other (from adlc)

dicarboxylic acid + polyalcohol group -> ester linkage and long chain that consists of many esters joined together.

Proteins and nylon
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A reaction that involves the carboxyl group and the amine (-NH2) group. Amino acids polymerize into peptides (short-chain amino acids) or proteins (long chain amino acids).
Both synthetic and natural polymers made by condensation reactions that involve a carboxyl group (-COOH) with a (a-NH2) group with amide linkages (-CONH-) are called polyamides. A protein with peptide amide (-CONH-) linkages is a polypeptide. Polyamides have incredibly strong hydrogen bonds, as proven by materials such as Kevlar which can stop a bullet.

Polypeptides:

amino acid + amino acid.... -> protein and water

Synthetic (ie. nylon)

dicarboxylic acid + diamine -> nylon + water

Carbohydrates and Cellulose
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Simple sugar molecules. Undergo a condensation polymerization reaction in which a water molecule is formed and the monomers join together to form a larger molecule. Glucose and fructose form sucrose, starch and cellulose form long chains of glucose. In cellulose, glucose monomers produce linear polymer chains that align side by side to form interchain hydrogen bonding. This makes cellulose bulky, inflexible and insoluble.

Natural (ie. starch)

glucose + glucose -> starch + water
glucose + glucose -> cellulose + water

Synthetic (cellulose triacetate)

cellulose + acetic acid + acetic anhydride -> cellulose acetate + ....

Synthetic
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Nylon, polyester

Natural
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Cellulose, starch, proteins, cotton
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