Characterization of Grafted Polybutadiene on a Poly(tetrafluoroethylene) Surface of Extremely Low Grafting Ratio

Butadiene monomer (BD) was block copolymerized by the initiation of mechanoradicals formed by mechanical fracture of poly(tetrafluoroethylene) (PTFE) powder. Polybutadiene (PBD) propagating radicals are much more stable and much mobile above melting temperature of butadiene monomer. In order to determine extremely low grafting ratio, nitroxide free radicals produced by reactions of 2,6-dichloronitrosobenzene with double bonds in PBD on PTFE are quantitatively detected. The determination of 10−3–10−1 (%) of grafting ratio was possible by the spin labeling method and the grafted chains were regarded as isolated chains. The extremely low grafting ratio could not be detected by other methods. The estimated number average molecular weight of the grafted chain was strongly dependent on the pressure of BD monomer.