Determination of the miscibility of phosphorus additives in polymer matrices by high resolution solid state NMR

Summary

The measurement of high resolution solid state NMR proton T_1p values (relaxation time in the rotating frame) provides a method for the study of the compatibility of phosphorus additives with polymer matrices. Results are compared for two commercial phosphorus stabilizers, bis (2,4 di-t-butylphenyl) pentaerythritol diphosphite (Phosphite 1) and tris (2,4 di-t-butylphenyl) phosphite (Phosphite 2), in 5% masterbatches in linear low density polyethylene (LLDPE). Phosphite 1 shows compatibility even when poorly mixed while the Phosphite 2 shows separation into two domains with different relaxation rates and different chemical shifts in the solid state.