The invention is a two-part composition comprising: A) in one part (i) one or more isocyanate functional prepolymers; and B) in a second part (ii) one or more compounds having isocyanate reactive groups; (iii) one or more fillers selected such that the composition is nonconductive; (iv) one or more catalysts for the reaction of isocyanate groups with active hydrogen containing compounds wherein either or both of the one or more isocyanate functional prepolymers and the one or more compounds having isocyanate reactive groups have solid organic particles grafted thereto such that the composition contains from about 6 to about 13 percent by weight of the total composition of solid organic particles. In a preferred embodiment, the second part comprises from about 35 to about 65 percent by weight of one or more compound having isocyanate reactive groups which have solid organic particles grafted to the backbone. In another preferred embodiment, the one or more isocyanate functional prepolymers comprise about 14 to about 20 percent by weight of solid organic particles grafted to the backbone of the prepolymers. In another preferred embodiment, the solid particles comprise a thermoplastic polymer or rubber-modified thermoplastic polymer.