SYNTHESIS AND TEST OF A STATISTICAL COPOLYMER - THE FURTIVE CHAIN

The synthesis of a polydimethylsiloxane chain with a random distributi on of deuterated and non-deuterated methyl groups is described. Cation ic polymerization provides an excellent mechanism for statistical sequ encing. The test for randomness is given by a neutron scattering exper iment on a semidilute solution. In the reciprocal interval (1 x 10(-2) angstrom-1, 1 x 10(-1) angstrom-1), the response is uniformly devoid of any copolymer correlation effect. A totally furtive chain can thus be inserted in a polymer solution, at zero average contrast between de uterated and non-deuterated chains.