This thesis investigates the effects of polyols as additives in polyvinyl chloride (PVC) processing. This substance class has already proven to be a good thermo-mechanical stabiliser in applications in the past, but it has not yet been possible to conclusively clarify why the polyols work, which mechanism they are subject to and to what extent other, mainly bio-based polyols act. The investigations carried out here are aimed at gaining a deeper understanding of polyols. An exact elucidation of the mecha-nism of action would go beyond the scope of this work, which is why this is not done here, and a pu-rely technical investigation is carried out, focussing on the effect itself.
Another important aspect of this work is the use of statistical Design of Experiment (DoE). By using this method, the aim of this thesis is to gain an initial impression of whether this approach is suitable for the formulation development of stabiliser mixtures (dry blends or one-packs). The background to this is that more and more effective stabilisers have come onto the market in recent years, but at the cost of using many different components. On the one hand, this leads to an overloading of the formu-lation and, on the other hand, information such as interactions between individual components or individual effects is completely lost or misinterpreted.
The polyols were tested for their influence on the static thermostability and the initial colour after single processing. For this purpose, a hard PVC formulation from the window sector and a soft PVC formulation from the cable sector were used. This covers two major areas of application for PVC. Alt-hough shortened formulations were used, experiments were also carried out on interactions with other formulation components. Starting with already established polyols, the step towards bio-based alternatives was taken relatively quickly. As polyols are not a separate substance class, carbohydrates, some of which are educts of sugar alcohols and were also investigated, were also included in the test series. In this case, there was a split between higher carbohydrates on the one hand and oleochemi-cally produced compounds on the other.
In addition to the interpretation of the DoE data, the data was also analysed in the conventional way to be able to better assess the significance of such test plans for PVC tests.