Radiation-initiated graft polymerization of methylmethacrylate onto poly(tetrafluoroethylene): Characterization by1H-NMR

Abstract

A broad-line 1 H-NMR study was carried out to examine the local structure of poly(methylmethacrylate) (PMMA) grafted onto Poly(tetrafluoroethylene) (PTFE). The NMR spectra were observed for three different samples with 1.0, 5.4, and 7.0 wt % PMMA over the temperature range from 150 to 380 K. With the help of selectively deuterated PMMA (PMMA-d 5 and PMMA-d 8 )-grafted samples, the NMR spectra were analyzed in terms of two components-a Gaussian (G) component, and a Lorentzian (L) component. Based on the second moments (͗⌬H 2 ͘) analysis, the L and G components were attributed to the 1 H-1 H dipolar interactions within one CH 3 group and the interactions of CH 3 groups that are closely located in aggregated PMMA chains. Combining the results with the temperature dependence of ͗⌬H 2 ͘ and the angular resolved XPS, the location and rotational motion of PMMA grafted onto PTFE are discussed.