Science Lab Report

Science Fair Lab Report:

Name: Olivia Peng

Class: 6P

Subject: Science

Turning Milk into Plastic

Aim: To find how the concentration of acetic acid in white vinegar affects how much casein plastic can be made from milk.

Research Question: Does the concentration of acetic acid in white vinegar affect how much casein plastic can be made from milk?

Background Information: Plastics are materials that don’t feel the same, but they can turn into different shapes. All plastics are called polymers.

Hypothesis: If I use higher concentrations of vinegar, then the production of casein plastic will increase. Measured weight in grams.

Independent Variables: The concentration of vinegar.

Dependent Variables: The amount of casein plastic produced for each concentration of white vinegar.

Controlled Variables: •

The type of milk.

•

The volume of milk.

•

The temperature of the milk.

•

The same type of vinegar for each concentration.

•

The volume of vinegar.

•

The temperature of the vinegar.

•

The duration of each reaction trial.

•

Consistency in stirring each batch.

•

Ambient temperature and humidity.

•

Length of time to drain the remaining milk-vinegar solution.

o

Materials:

•

Mugs or other heat-resistant cups

•

Masking tape

•

Permanent marker

•

Teaspoon spoon

•

White vinegar

•

Milk

•

Microwavable liquid measuring cup

•

Cooking or candy thermometer.

•

Spoon

•

Paper towels

Procedure: 1.

Buy all the materials.

2.

Heat up the milk until it’s 45 degrees Celsius.

3.

Add 65ml vinegar into the milk using 3% and 9%.

4.

Use teaspoon and stir it for each batch the same speed for one min each.

5.

And then I pour the mixture over into a cloth and let it drain off the

residue. 6.

I use paper tower to dry the casein plastic.

7.

I color it.

8.

Put it in a cookie cutter.

9.

Let’s it dry.

10.

And I have to do it 14 times.

Ci: Data: Table showing weight of plastic: Concentration of Acetic Acid

Weight of Plastic in Grams

3%

9%

Graph showing weight in grams of plastic:

1 trial: 28g 2 trial: 37g 3 trial: 37g 4 trial: 23g 5 trial: 19g 6 trial: 32g 7 trial: 28g 1 trial: 25g 2 trial: 23g 3 trial: 34g 4 trial: 41g 5 trial: 39g 6 trial: 28g 7 trial: 27g

Cii: Patterns: The data shows that the results about my experiment. I used 3% of vinegar and 9% vinegar, and it is the results that I got, and it’s the weight of the casein plastic. And I test the plastic in grams. Experiment results were analyzed by Mr. Ken Fraley, Medical Statistician at Rice University, Houston, Texas. This is what he told me. He used the Two-Sample T-Test at 95% Confidence Level (CL). A CL of 95% means if this experiment were done 100 times, the difference between the 3% and 9% results would be significant 95 times. In that case, the PValue (probability) would be < 0.05. My results’ P-Value was 0.624, which means the difference between the two test groups was not significant. Mr. Fraley also pointed out that the standard deviations of the two groups were large (6.77 and 7.05), meaning the data were quite spread out, and not in two separate groups. So, the big question is, “Why did the 9% group, with three times as much acetic acid as the 3% group, not have, significantly greater casein plastic production? I would like to thank Mr. Fraley for his hard work. In my own words: The Two-Sample T-Test was used at 95% Confidence Level. The 95% means if you do 100 trials, 95 times the results between the 3% and 9% vinegar would be much different. That didn’t happen. Instead the results were very close.

Ciii: Evaluate hypothesis: My hypothesis wasn’t supported because from the data it shows that the results doesn’t have much differences between the results. It should be three times then the 3% vinegar’s results.

Civ: Evaluate the method:

I will do all of the experiment in one day, because the temperature will change every day and it’s will not be the same every time. I will put on the AC to keep the temperature the same, so every time the temperature is the exact same. I compared 3% acetic acid vinegar and 9% acetic acid vinegar. My 3% vinegar casein plastic production averaged 29g. I thought that by comparing 9% vinegar this second trial would make three times as much casein plastic (about 90g), but it’s averaged only 31g. Why? I think maybe because I used UHT milk. I learned that UHT milk is pasteurized at 135 degrees Celsius. Normal milk is pasteurized at 99 degrees Celsius. The casein molecule is changed (denatured) when the milk is heated up. The casein in UHT milk is probably changed much more than in normal milk. Therefore, the casein in UHT milk may not work as well to create plastic. Maybe the best solution would be to use raw milk to casein plastic.

Work Citied: Turn Milk Into Plastic! | Science Project https://www.sciencebuddies.org/science-fair-projects/project-ideas/Chem_p101/chemistry/turn-milk-intoplastic#procedure

Sculpted Science: Turn Milk Into Plastic! Science Buddies - https://www.scientificamerican.com/article/bring-science-home-milk-plastic/

Turn Milk Into Plastic: The Science Of a Protein https://www.abeka.com/Resources/HomeschoolArticles/MilktoPlasticExperiment.aspx