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Turn Milk into Plastic

Postby saritachopra » Wed Mar 01, 2017 12:51 am

Hi, my son who is in 4th grade is doing the science fair project of Turning Milk into Plastic. He throughly enjoyed doing the experiment, but we are confused with our results. His question for the project is 'What is the best recipe to turn milk into plastic - how much vinegar is needed to give you the most plastic'? He thought 8 teaspoon will give the best yield. When we weighed the yield immediately after project - 2 tsp and 8 tsp seemed to give kind of similar yield (around 40 grams) and 4 tsp gave marginally lesser (around 36 grams). But once it dried after 48 hours we weighed again - 2 tsp gave the most at 20 grams, 4 tsp close to 18 grams and 8 tsp 15 grams. This means we don't need 8 tsp to give us the best yield. Is the reason because all the casein in the milk is turning into plastic with the 2/4 teaspoon itself and that we the extra acid in 8 teaspoon is making the milk very acidic. Or that there is no more casein left in the milk for the 8 teaspoon of Vinegar to covert into plastic. We are still confused whether 2 tsp gave us the best yield or 4 tsp. the texture of the yield of 2 tsp is slightly more gooey and it seems like it has some milk in it (hence probably weighs more) whereas 4 tsp hardened better. We would like to know what you think is the conclusion...

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Re: Turn Milk into Plastic

Postby MadelineB » Wed Mar 01, 2017 10:11 pm

Hello saritachopra,
This is an interesting project and you are asking good questions. Did your son repeat the experiment 3 or more times as suggested? If he has 3 observations (replicates) for each of the 4 recipes, then he could see if the "best" recipe was best for each of the 3 replicates. I know the procedure talks about using the average of the 3 observations for each recipe, but looking at the individual observations separately for each recipe should give you a better idea how much the results varied between each of the 3 replicates. Your son could make a graph, showing the value of individual weights for each of the 3 replicates for each of the 4 recipes. Maybe you could scan that and upload it to show us! That would be fun to see!

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