Polymer Chemistry Research Experience. Support: NSF Polymer Program NSF (PI: Chang Ryu)/RPI Polymer Center

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1 Polymer Chemistry Research Experience. Support: NSF Polymer Program NSF (PI: Chang Ryu)/RPI Polymer Center Student Name: Michael Hyams Student Affiliation (City, State): Mamaroneck, NY Picture of 3D printed samples/3d Doodled samples

2 Notable Creations More pictures of your 3D plastic samples Shapes Ammonia (left) and PLA (right) The clear blue plastic is real PLA Tubes, RPI and a lego brick approximately to scale

3 Notable Creations Geometric tower 3D-printed bust of me Spiral towers

4 FTIR Explanation Stands for Fourier transform infrared spectroscopy. Shines a very wide spectrum of infrared and refracts it with a diamond crystal into the sample. Different types of chemical bonds vibrate and oscillate at specific frequencies. When the frequency of light matches the frequency of bond vibration, it is absorbed. Otherwise, it passes through. FTIR measures the percentage of IR light that passes through the sample (or percentage absorbed by the sample, depends on the software) over a wide range of wavelengths and graphs it. For the graph, wavelength is converted to wavenumber the amount of wavelengths in one centimeter, measured in cm -1 or 1/cm. Certain types of bonds absorb certain wavenumbers of IR. These show up as peaks on the graph cm -1 indicates C=O bonds, or ketone groups, stretching cm -1 indicates carboxylic acid groups (R-COOH) stretching cm -1 indicates C C H bonds stretching. C=C H bonds stretching are indicated above 3000 cm -1, so a lack of any sharp peaks above 3000 cm -1 implies a lack of any C=C bonds. Broad peaks from cm -1 indicate the OH bonds of alcohols stretching. C H bonds bending shows in peaks often well below 1000 cm -1.

5 Polymer Chemistry Research Experience. Support: NSF Polymer Program NSF (PI: Chang Ryu)/RPI Polymer Center FTIR Results of ABS or/and PLA (use more pages, if needed) Blue ABS Plastic C=C-H 3000 cm -1 C-C-H C=O (from dye) 3000 cm -1 Clear PLA Plastic C=O X C-C-H

6 ABS color affects FTIR results Orange ABS Dye/additive difference Yellow ABS C=O (X) C=O This difference is due to the presence of C=O bonds in the yellow coloring but not the orange coloring.

7 DSC Explanation Stands for Differential Scanning Calorimetry. Increases the temperature of the sample at a constant rate. Measures the rate of heat flow in the sample in W/g. Graph normally forms a straight line that gradually decreases. Discontinuities in the line indicate phase change. Plastics have a glass transition temperature and/or melting temperature. On every graph there is one or two dips on the line. When there is two, the first one is glass transition and the second is melting.

8 Polymer Chemistry Research Experience. Support: NSF Polymer Program NSF (PI: Chang Ryu)/RPI Polymer Center DSC Results of ABS or/and PLA (use more pages if needed) Blue ABS, 6.98 mg (DSC, Heating at 10 o C/min) Tg The yellow ABS had very similar results to the blue

9 Black PLA, 6.97 mg (DSC, 10 o C/min) Tg Cold crystallization Tm The first dip represents the glass transition temperature. The hill between the two dips represents crystals forming. PLA is semicrystalline and tries to form crystals. During its manufacturing it was likely cooled too quickly to form crystals. After the glass transition, the PLA molecules have more degrees of freedom and form crystals as a result. The second dip represents the melting point. The other PLA had similar results.

10 My Sample Michael Hyams Goldfish wrapper Exothermic Tm The results of DSC on a piece of Goldfish wrapper were not very clear. There appears to be a slight dip around 160 C, which is likely a melting point. This would indicate that the wrapper is likely made of Polypropylene (PP). However, it should be tested again for more clear results.

11 Polymer Chemistry Research Experience. Support: NSF Polymer Program NSF (PI: Chang Ryu)/RPI Polymer Center SUMMARY I learned a lot from this program and had a great time. I learned about several common plastics; what they are, what they re made of, and how they re used. In doing so, I also learned more about recycling and what the numbers in the triangles mean. I learned that bonds in molecules will vibrate with specific frequencies and how IR light interacts with those bonds. With this information, I learned about FTIR spectroscopy. It was very fun and interesting to test out various samples with the FTIR machine and compare the results. I also learned how different plastics have phase changes in different ways some melt and some only have glass transition points and then decompose instead of melt. Using DSC was very helpful in identifying plastics, errors aside. Using the 3Doodler pen was very fun and I made lots of cool stuff. My creations as well as the 3D-printed bust of me will make great souvenirs! The labs we did were very cool, especially the UV curing and liquid nitrogen. It blew my mind how fast the resin would cure. Just a few seconds under the lamp would do it. In the smaller machine with the laser and thermometer, the polymerization reaction was shockingly exothermic. I was amazed when the temperature shot up from 40 C to 160 C in only about a second. The liquid nitrogen was very fun to mess around with. I discovered that cooling packing peanuts in liquid nitrogen allows you to place them on the table and smash them with your fist, causing it to shatter and go all over the place. It would turn soft plastics hard due to lowering it below their glass transition points, which were somewhere in between liquid nitrogen temperature and room temperature. I had a napkin in my pocket and tried it in the liquid nitrogen, it actually absorbed it! I pulled it out and it was wet, dripping nitrogen, and was very cold. This program also gave me a taste of what it s like to be away from home, which is useful experience for the future. I learned very much and had an excellent time from this program. Michael Hyams (Mamaroneck, NY)