ON THE SCATTERING OF NEUTRONS BY POLYMERS AT HIGH SCATTERING ANGLES

In the case of Gaussian chains, in solution or in bulk the expansion o f the form factor at large q gives a term in q(-2) which allows the de termination of the statistical element and a term in q(-4) which depen ds only on the structure of the chain (presence of cross-links, branch es, loops etc. One can evaluate this term for all the branched structu res being able to take into consideration the polydispersity. One give s the result fot simple rings and a general formula for simple network s. The same methods can be used for block copolymers. Asan exampleones hows that this formulation allows to measure the kinetics of transeste rification.