DPT

Uses of IR

limited amount of sample, for rapid analysis, identifying absorbed compounds on glass and other surfaces, chemical functionalities of fibers, probing compositions of polymer films

higher because it does not have a monochromator and all wavelengths of light hit the detector at once making the signal much higher than the noise “multiplex advantage” The lamp power is also very bright compared to the detector noise because all wavelengths are striking simultaneously

does FTIR detect higher or lower absorbances than UV-Vis

6 absorbance unit

limit of linearity for FTIR

effects the chemical and mechanical properties of the polymer

what does the R group do on a polymer R=-CH=CH₂

polyethylene

used for sandwich bags

polypropylene

used for soda bottles

polystyrene

coffee cups

polyvinyl chloride (pvc)

used for food wraps and piping

teflon (polytetrafluoroethylene)

material for making non-stick pans

additives

added to affect flammability and pliability of polymers

remove the phthalate added as plasticizer and make Tygon plia

goal of this lab

name and structure of the plasticizer

Bis(2-ethylhexyl) phthalate

2800 to 3000 cm^-1

range to expect methylene stretches

structure of polystyrene

structure of polyethylene

structure of Teflon

acetone

the solvent used to extract the plasticizer

the polymer became more malleable and transleucent

effect of the plasticizer removal

Teflon → polystyrene → polyethylene

order for most pliable unknown polymers