Synthesizing a Silicate Chain to Form Superballs

Question What does combining sodium silicate and ethyl alcohol create? How does your bouncy ball bounce? What does combining sodium silicate and ethyl alcohol create? How does your bouncy ball bounce?

Synthesizing Inorganic Polymer  In this lab experiment, you will synthesize an inorganic polymer based on silicon.  Inorganic polymers are polymers with a non-carbon backbone. Silicon is an element directly below carbon, yet the chemistry of carbon and silicon are very different.  In this lab experiment, you will synthesize an inorganic polymer based on silicon.  Inorganic polymers are polymers with a non-carbon backbone. Silicon is an element directly below carbon, yet the chemistry of carbon and silicon are very different.

Silicones & Polymers Silicones are largely inert compounds with a wide variety of forms and uses. Typically heat-resistant, nonstick, and rubberlike. They are frequently used in: Cookware Medical applications Sealants Lubricants Insulation Silicones are largely inert compounds with a wide variety of forms and uses. Typically heat-resistant, nonstick, and rubberlike. They are frequently used in: Cookware Medical applications Sealants Lubricants Insulation

Silicones are polymers that include silicon together with carbon, hydrogen, oxygen, and sometimes other chemical elements.

Polymers (Greek poly means many and (meros), meaning "part”)  A polymer is a large molecule (macromolecule) composed of repeating structural units connected by covalent chemical bonds.  Polymerization – joining of many small molecules to form a large molecule.  Well-known examples of polymers include plastics, DNA, and proteins.  A polymer is a large molecule (macromolecule) composed of repeating structural units connected by covalent chemical bonds.  Polymerization – joining of many small molecules to form a large molecule.  Well-known examples of polymers include plastics, DNA, and proteins.

Discussion  The super ball is a variation of a simple silicone. Silicone is the term used to describe any organosilicon oxide polymer in which the structural unit is usually: R is an organic, usually a methyl group.

Sodium silicate solution is produced by fusing sand (SiO 2 ) n and soda ash (Na 2 CO 3 ) in a furnace at about 1300 o C. The final product, Na 2 O (SiO 2 )n is also called water glass. The reaction with ethyl alcohol produces a super ball which is most likely a silicone elastomer where the R is (- O - CH 2 CH 3 ).

Elastomer Elastomer is a big fancy word, and all it means is "rubber". Some polymers which are elastomers include polyisoprene or natural rubber, polybutadiene, polyisobutylene, and polyurethanes. What makes elastomers special is the fact that they Bounce and can be stretched to many times their original length, and can bounce back into their original shape without permanent deformation. Elastomer is a big fancy word, and all it means is "rubber". Some polymers which are elastomers include polyisoprene or natural rubber, polybutadiene, polyisobutylene, and polyurethanes. What makes elastomers special is the fact that they Bounce and can be stretched to many times their original length, and can bounce back into their original shape without permanent deformation.

Materials Needed 20 mL Sodium silicate solution 10-mL Ethyl alcohol, CH 3 CH 2 OH, 95%, wooden splint small paper or plastic cup Caution: This activity requires the use of hazardous components and/or has the potential for hazardous reactions. Please review the Safety Precautions section on the following page and relevant Material Safety Data Sheets before beginning this activity. Caution: This activity requires the use of hazardous components and/or has the potential for hazardous reactions. Please review the Safety Precautions section on the following page and relevant Material Safety Data Sheets before beginning this activity.

1. Measure out and add 20 mL of sodium silicate solution to the paper cup. 2. Measure out 10 mL of 95% ethyl alcohol and add it to the paper cup. 3. Stir the mixture with the wooden splint in a regular circular motion. 4. As the mixture solidifies, squeeze out the liquid with gloved hands; place the solid in the palm of your hand and form the solid into a ball. 5. As you form the ball, continue to gently press out the excess liquid. 6. Bounce the ball and measure the height of the bounce! Procedure

Measure the height that your superball bounced to. Trials  Height (cm) Trial 1 Height (cm) Trial 2 Height (cm) Trial 3 Height (cm) Average Student Name

Tips  Adjust the amount of alcohol used (anywhere from 5 to 15 mL) and observe the differences between the superballs.  The superballs will vary in how brittle they are.  The silicone super ball is brittle and may crumble. It may be reformed by pressing it between the palms of your hands.  The super ball should be stored in a closed or airtight container when not in use.  Adjust the amount of alcohol used (anywhere from 5 to 15 mL) and observe the differences between the superballs.  The superballs will vary in how brittle they are.  The silicone super ball is brittle and may crumble. It may be reformed by pressing it between the palms of your hands.  The super ball should be stored in a closed or airtight container when not in use.

Safety Precautions  Ethyl alcohol is a dangerous fire risk; it is flammable. The addition of denaturant makes ethyl alcohol toxic by ingestion.  Sodium silicate solution is very alkaline, it is a skin irritant.  Wear chemical splash goggles, chemical-resistant gloves, and a chemical-resistant apron.  Ethyl alcohol is a dangerous fire risk; it is flammable. The addition of denaturant makes ethyl alcohol toxic by ingestion.  Sodium silicate solution is very alkaline, it is a skin irritant.  Wear chemical splash goggles, chemical-resistant gloves, and a chemical-resistant apron.

Polymers Polymers – large chainlike molecules made from many small molecules called monomers  Simplest polymer – polyethylene  Polyethylene results from addition polymerization.

Polymers  Condensation polymerization – a small molecule (often water) is released for each addition of a monomer to the polymer chain Copolymer – 2 different types of monomers combine to form the chain  Nylon (co-polymer) and as you can see carbon based.

Sodium Silicate polymer  When sodium silicate and ethyl alcohol are put together, the silicate particles begin to link up with each other to form long chains as the ethyl groups (sometimes shown as "R") replace oxygen atoms in the silicate ion. (Some become cross-linked between chains.) Water molecules are by-products of the formation of the polymerization bond.  The large molecule is a solid.  When sodium silicate and ethyl alcohol are put together, the silicate particles begin to link up with each other to form long chains as the ethyl groups (sometimes shown as "R") replace oxygen atoms in the silicate ion. (Some become cross-linked between chains.) Water molecules are by-products of the formation of the polymerization bond.  The large molecule is a solid.