CHEMISTRY PROJECT

AIM: Preparation of Slime

MATERIAL REQUIRED: Samples of various polymers, Balance, Elmer's or other white glue, Borax, Polyvinyl alcohol, Sodium polyacrylate, Salt, Sugar, Baking soda, Sebacoyl chloride, Hexaminediamine, Paper clip, Glass stirring rod, Beakers (150 mL and 400 mL, 1L), Water ( tap and distilled), Paper or plastic cups (smallest size available), Wooden stir sticks, Graduated cylinders.

THEORY:This is what happens when a solution of Polyvinyl Alcohol (PVA) and a solution of Sodium Metaborate (Borax) are mixed together. Polyvinyl Alcohol is a repeating chain or polymer of the Vinyl Alcohol unit:

When the PVA is dissolved in water, the vinyl alcohol units link up to form chains. This results in a thick, syrupy appearance to the solution. When borax is added to the PVA solution, the chains of PVA cross - link to form aviscoelasticgel. The cross linking is weak, so the links continually form and break under the weight of the gel, or with handling. Leave a ball of the slime on a flat surface, and it slowly flattens out as the molecular chains slide over each other, rearrange themselves and reconnect. But if you pull suddenly on the material, it snaps.PROCEDURE: 1. Place 50 mL of 4% polyvinyl alcohol solution into a disposable cup. Add a couple drops of food colouring and stir with a wooden stick. 2. Pour 5 mL of saturated sodium borate solution (4%) into the cup while stirring. The mixture will gel almost immediately but keep stirring until smooth. 3. To observe the properties of slime, knead it into a ball. Hold a small part of the ball and watch it stretch without breaking. Try stretching the slime quickly and see how it will break under these conditions. Slime will also pick up ink from paper. The design will be transferred to the slime. 4. The slime will last two days to a week. Store it in an air tight, plastic sandwich bag. When the slime starts to mould, dispose of it in a waste container.RESULT: Slime is preparedPRECAUTIONS: 1) No one should ingest the material and to use it only for the purposes intended.2) Do not allow slime to remain on clothing, upholstery, carpet, or wood surfaces.3) Wear chemical splash goggles4) Slime will stain on many surfaces. Clean up the slime as soon as possible