Chemistry 1027A/B Lecture Notes - Lecture 4: Ultimate Tensile Strength, Polypropylene, Low-Density Polyethylene
16 May 2016
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Document Summary
Polymers macromolecules, have a high relative molecular mass, made up of many repeating subunits. Monomer: the (smaller) chemical entity which gives rise, upon reaction, to the polymer. Repeating unit: the structural unit enclosed in brackets. Can be subject to physical and chemical changes, to give useful products (easy to manipulate) They don"t rot, rust, corrode, or break easily, can be permanently coloured. Can be drawn into fibres, sheets, soft rubbery materials, elastic materials, etc. Some are derived from crude oil and natural gas (small percentage of the polymer industry) Commonly found in the form of a container (polymeric containers) It will stay there: major cause of pollution in oceans. Polymers have lots of different architecture corresponds to its properties. Carbohydrates polysaccharides (cellulose: cellulose (hair, wool, cotton, trees) proteins, lipids, natural waxes, nucleic acids (dna) Oxygen is going up: the one simple stereo chemical difference is what allows us to digest starch, but not cellulose.
