Question

A polymer with chiral centers was tested for head to head/head to tail arrangement using various assessments. Which of the assessments provided inaccurate results?

		UV spectroscopy
		Differential Scanning Calorimetry
		Infrared Spectroscopy
		Nuclear Magnetic Resonance Spectroscopy

Answer 1

Since the head-to-head/head-to-tail polymerization is different types of arrangements of molecules while doing the polymerization reaction. Thus the techniques that can identify the structure/special types of bonds present in the molecule, will give us accurate results.

The assessment that will provide inaccurate results is UV spectroscopy since in polymer there are rarely any double bonds and thus the intensity of UV absorption will be very less and it can not definitely tell us the exact type of arrangements that have been generated in the structure.

While DSC can tell us the melting point of any polymer and thus it is head-to-head/head-to-tail, we can know from the different values of their melting point. IR spectra is another important technique that tells us about the type of bonds present in the molecule. NMR tells us about the environments around the atoms present in the molecule.