Poly(oxy(methyl-1,2-ethanediyl)), alpha,alpha,alpha-1,2,3-propanetriyltris(omega-(2-aminomethylethoxy)-, polymer with alpha-(2-aminomethylethyl)-omega-(2-aminomethylethoxy)poly(oxy(methyl-1,2-ethanediyl)) and 1,3-bis(1-isocyanato-1-methylethyl)benzene