Abstract: Proton NMR spectra of fluoro silicone oil and rubber (polymethyl r,r,r-trifluoropropyl siloxanes, have been assigned by using a series of modle compounds. A method was developed for the determination of molecular weight of oil. It was based on the measurment of end group.For oil ended bymethyl group,

For oil ended by hydroxy group,

S_{CH3 (a)} and S_CH3(b) are peak areas of end methyl group and remaining methyl group, respectively. X and M is polymerization degree and molecular weight, respectively.
High sensitive proton NMR spectra were used for the determination of vinyl group in rubber and composition in a series of copolymers,
vinyl mole%=(S_-CH-CH2)/S_-CH2×(2)/3
S_-CH=CH₂ and S_-CH2, are peak areas of vinyl group and -CH₂, group, respectively.