Microstructure determination of poly‐(1,3‐pentadiene) by a combination of infrared, 60‐MHz NMR, 300‐MHz NMR, and X‐ray diffraction spectroscopy

A quantitative procedure has been developed for characterizing the complete microstructure of polymers of 1,3‐pentadiene, including the tacticity of any crystalline component. This can be accomplished by a combination of infrared spectroscopy, X‐ray crystallinity, and 300‐MHz NMR spectroscopy. A series of high structural purity polymers were synthesized with a series of previously unreported mixed microstructures. These samples were characterized by using the three techniques mentioned, including the previously unreported 300‐MHz NMR data. With those results a 60‐MHz NMR/IR method of spectroscopy was developed to determine the composition of poly(1,3‐pentadiene)s in terms of percent cis ‐1,2‐, cis ‐1,4‐, trans ‐1,4‐, and 3,4‐pentadiene units.