Solid state two-dimensional NMR studies of polymeric diphenylmethane diisocyanate (PMDI) reaction in wood

摘要

N-15-H-1 heteronuclear correlation (HETCOR) NMR experiments were employed to study the products from the reaction of N-15 enriched polymeric diphenylmethane diisocyanate (PMDI) with cellulose, lignin, water, and aspen and southern yellow pine wood samples. Both urea and biuret structures can be clearly recognized in the wood/PMDI composites. Two peaks around 104 to 106 ppm result from different chemical environments of urea structures.