A+-+Polymers+&+Polyester

// Leanne Wang //
 * __ What are polymers? Explain the chemistry and application of one polymer. __**

Here are a couple of videos introducing polymers: media type="youtube" key="uCXBu8j6dlk?fs=1" height="385" width="640"

media type="youtube" key="pP_HYeNxwI0?fs=1" height="385" width="480"

To summarize:

Polymers are macromolecules made up of repeating units. They can be organic or inorganic, and both occur naturally and are synthesized. Some examples of polymers that make up our everyday life include: ribonucleic acids (e.g. DNA), polysaccharides, proteins, graphite, diamonds, concrete, nylon, etc… Polymers are synthesized because they often offer a lot of advantages over other materials. For example, compared to metals, polymers are often more lightweight and has more strength per weight. __ Nomenclature __

Many are known by common names/acronyms, instead of their IUPAC names l Acronyms: polystyrene or PS is poly(1-phenylethylene) l Trade names: Fortrel® polyester is a poly(ethylene terephthalate) or PET fiber l Also generic names: rayon, polyester, nylon etc. __ Structure __

l Made up of similar or identical repeating subunits: **monomers** l ** Degree of polymerization ** or **DP** refers to the number of repeating units in a polymer; polymers with large number of DP is referred to as a “high polymer” l ** R groups ** are variables within the chain l Structure can be studied on different levels: **Primary**, **Secondary**, **Tertiary**, **Quaternary** __ Polymerization __ Two methods of polymerization: l ** Chain/Addition Polymerization ** : monomers are dissolved in a solvent, and then react with each other when the solvent is removed. No atoms are lost, and the reaction is very quick. l ** Condensation Polymerization ** : monomers are linked together as atoms are lost (often water). Often involved two or more different types of monomers, and the reaction is slower

=__ Polyesters __=



// Boxes represent an “R”-group – any group of atoms //

l ** Condensation polymerisation ** : water is released in the process l A **monocarboxylic acid** will react with an **alcohol** to form an **ester** l A **dicarboxylic acid** (molecule with a carboxylic acid on each end) reacts with an **dialcohol** (molecule with an OH on each end) l A chain of **ester groups** is formed -> polyester ||
 * __ Formation of Polyester __

Polyester is considered as a type a petrochemical. It is most often used in textiles, with PET, PCDT, and PEB being the most commonly used. Polyesters have high strength and durability but have poor moisture absorption. Polyester is especially useful as a component in blends with natural fabrics by providing strength, abrasion resistance, and low cost. They do, however, have a tendency to absorb oil and retain oil stains (esters have long non-polar alkyl chains!).

**Sources** Carraher, C. (2008). Polymer. McGraw-Hill Companies. Retrieved October 24, 2010. (http://www.accessscience.com/content.aspx?searchStr=polymer&id=535100#BIB)

(2009). Polymer. Compton's by Britannica. Retrieved October 25, 2010. (http://elibrary.bigchalk.com)

Clarkson, R. (2005). Junior Part - Organic Chemistry. Retrieved October 26, 2010 from Chemistry Rules!: (http://www.chemistryrules.me.uk/​junior/​organic.htm)

(2009). Fiber, man-made. fiber, man-made. Encyclopedia Britannica. Retrieved October 26, 2010 from (http://elibrary.bigchalk.com)

(2009). Petrochemical. petrochemical. Encyclopedia Britannica. Retrieved fr October 26, 2010 from (http://elibrary.bigchalk.com)