Quantifying chain dimensions and the interaction parameter between vinyl alcohol and vinyl acetate in PVAc

The RPA scattering from blends of poly(vinylacetate) "PVAc" and its hydrolysed counterpart, poly(vinylalcohol) "PVA" are is important to understand for film-forming applications and in particular the dissolution of soluble unit dose detergent pouch technologies. Our recent SANS experiments on a family of well-defined PVA and PVAc materials revealed some surprising and apparently inconsistent behaviour. As the PhD project to study these materials is set to end in October 2024 we request some rapid access beamtime for a simple SANS experiment to resolve and decouple the ambiguities and enable publicaiton from this and the previous experiments. Careful simulations show that unless the sample volume is very well defined, then the impact of changing interaction parameter and chain dimensions on scattering cannot be de-coupled and we require some repeat experiments with a new method to prepare very well-defined sample volumes. We also wish to exploit our backbone-deuterated PVA samples in blends to study the RPA scattering from PVA/dPVA at much higher concentration than was previously possible to resolve the chain structure of the 'pure' materials.