Grade Level: 9th; Type: Chemistry
Determine how the properties of polymers can be changed.
- What is organic chemistry?
- What is a polymer?
- How are polymers formed?
- What are some natural polymers?
- What are some synthetic polymers?
- How do we change polymers?
- How has this branch of chemistry changed our lives?
On the information level, the student becomes acquainted with organic compounds known as polymers. Polymer molecules contain large numbers of atoms held together by covalent bonds. A covalent bond is a chemical link between two atoms and is produced by shared electrons in the region between the atoms. For example, in water there is a covalent bond between the O atom and each of the H atoms. Polymers are found in nature. These include starch and cellulose. Polymers are also man made. These include plastics, synthetic fiber such as nylon and synthetic rubber. In this project, the student will attempt to change the properties of this polymer.In the process, the student will be using the scientific method by first formulating a hypothesis, testing that hypothesis in a systematic way, recording observations, analyzing data and formulating a possible conclusion. This is an excellent introduction to organic chemistry.
- Safety goggles
- Lab coat
- 2 small identical glass jars, 15 mL of 50 per cent white- glue solution
- 5mL of 4 percent borax solution (do not touch this solution)
- 1 heavy duty plastic self-lock bag
These materials may be purchased from Science Kit or Chem Scientific.
- Gather all the materials you will need for this project. These include safety goggles, lab coat or apron, gloves, 2 small identical glass jars, 15 mL of 50 per cent white- glue solution, 5mL of 4 percent borax solution (do not touch this solution), 1 heavy duty plastic self-lock bag.
- Reproduce the data chart provided below so that you may readily record your observations.
- Formulate and record your hypothesis. What do you anticipate will be the result or outcome of this experiment?
- Put on your safety gear. Pour 15mL of the white –glue solution into one of the small jars.
- Observe the solution and record your observations in your data chart. Note the solutions color, and odor.
- Before you note the texture, carefully swirl the jar around. Do not touch the solution.
- To get the odor, do not place your nose to the jar; just fan the top of the jar.
- Now, careful, do not touch the borax solution. Use care as you fill the other jar with 5 mL of Borax solution. Record your observations on the borax solution in your data chart. Use the same procedure as steps # 6 and 7.
- You are now confronted with a white glue solution. Pour the solution into the plastic bag.
- Now add the borax solution from the other jar into the bag. Close the bag.
- Now knead the solutions through the bag .Try to get them evenly mixed. Do not let any liquid remain.
- Now remove the product from the bag, knead a bit more. Stop and wash those hands.
- Record your observations in the data chart.
- You have just produced a polymer known as polyvinyl acetate. Research its properties.
- Write up your report. What do you think happened to the polymer molecules after they were mixed with the borax solution? What role do you think the borax played? Can the properties of a polymer be changed? What does all of this have to do with white glue? Can you explain how glue serves to bind things together? What happens to the polymer molecules when the glue is drying? Has a chemical reaction taken place? How do you know?
- You may want to take photos of the before and after product. Glue it into your report! Good luck! Do not forget to include your bibliography.
Data Chart: Observations
Terms/Concepts:Organic chemistry; Elements; Compounds; Mixtures; Properties; Polymer; Monomers; Branched polymer chain
Odian, George; Principles of Polymerization, 3rd ed., J. Wiley, New York, 1991. Jang, B. Z.; Advanced Polymer Composites: Principles and Applications, ASM International, Materials Park, OH, 1994.