In this proposal we are planning to study the early stage of polymer instability at buried interfaces by developing the off-specular neutron reflection. The destabilisation of the interface of a polymer/polymer systems by long range forces will be followed at the early stage by a detail analysis of the off-specular reflection signal analysed in the DWBA approach combined with the specular reflection. The effect of Van der Waal forces on the stabilisation or destabilisation of the interface will be also probed. This project will develop the use of off-specular scattering at ILL, an important tool for the interface analyses still not fully explored in soft matter, and is in the frame of a ILL PhD student that will start in April 2016.