Melting Point of Different Plastics

For my lab, I will be testing the melting points of different plastics.

My Independent Variable will be the different plastics

My Dependent Variable will be the melting point of different plastics

My Control Variable will be the amount of plastic I will be putting into the oven to melt.

To determine the melting point, I have to be observing the plastic for the whole time while it is being heated. I have to be observing very closely because, to determine the melting point I have to see when the plastic starts to melt and when it is completely melted (1). I will be using two plastics two compare each other, I will use Polyethylene terephthalate which is the most produced plastic in the world and Polyethylene, these two plastics are the most common plastics (2). I will be comparing the melting point of each of the plastics and finding out what plastic is more resistant to heat. Polyethylene terephthalate is thermoplastic which means that it reacts to heat in a certain way. The melting point of Polyethylene terephthalate is roughly 260 degrees Celsius (2). Because polyethylene terephthalate is thermoplastic, when melted it turns into a liquid substance and doesn't just burn up. I think that this plastic will therefore be more resistant to heat because it doesn't burn and disintegrate but it turns into a liquid instead (2).

(1)"Determination of Melting Point." Wired Chemist, Claude Yoder,

     www.wiredchemist.com/chemistry/instructional/laboratory-tutorials/
     determination-of-melting-point. Accessed 20 Jan. 2019.

(2) Staff, Creative Mechanisms. "The Eleven Most Important Types of Plastic."

     Creative Mechanisms, 21 July 2016, www.creativemechanisms.com/blog/
     eleven-most-important-plastics. Accessed 20 Jan. 2019.