Optimisation de formulations de mousses de polyuréthane pour des applications en génie civil

Abstract

Polyurethane foam is an alveolar material that is light weight and has good mechanical and thermal properties. It is currently used in isolating panels for civil engineering applications. As this market is constantly growing, improving products and processes is an important issue for manufacturers. The first step of this research project was to create and validate a complete procedure in order to manufacture laboratory samples with the same properties as factory-produced insulation panels. The second step was to study and quantify the influence of surfactant on the specifications of the final product, using the fabrication procedure developed. The goal of this laboratory method is therefore to help improving current products but also solving some problems encountered on the production line. During the development of the laboratory method, a first fabrication technique, involving the use of a magnetic mixer, was tested. But this method did not allow a satisfactory mixture of the components. The mixture quality was then improved through a second laboratory procedure, based on mixing at a higher speed in a beaker positioned below the mold. Nevertheless, the foaming method did not produce a cellular orientation similar to the one observed for the insulation panels manufactured in the production line. To solve this problem, a third method, based on the use of peristaltic pumps and a static mixer, allowed to lay a line of foam in the mold and obtain the required cells orientation. The challenge of this technique was to obtain a homogeneous mixture of the components. The implementation of a fourth manufacturing method, which involves pouring the foam into the mold from a beaker in which the components were mixed, allowed obtaining a homogeneous mixture of the components and a good orientation of the cells, as in the factory-produced insulation panels. This technic permits a good control of the quantities of products and produces samples of the desired size and satisfactory quality to the naked eye. This procedure was validated according to three requirements for the final product: density, in compressive and tensile strength. The results from these tests show that the laboratory produced samples had the required characteristics according to the standard requirements. An analysis of variance also proved the repeatability of these results. After the validation of the laboratory procedure, samples with different amounts of surfactant were prepared using this procedure. They have been characterized in terms of density, compressive and tensile strength, and thermal resistance. The density data showed a clear evolution as a function of amount of surfactant used in the product, in agreement with the literature. Thermal resistance results did not display any evolution as a function of the amount of surfactant within the tested range, in agreement with the literature. The compressive strength results appear to show a different trend compared to what is reported in the literature but additional tests are required to confirm these conclusions. The tensile strength results showed no change as a function of surfactant concentration. These results in this study confirm the validity of laboratory procedure and provide a first analysis of the effect of surfactant concentration on the finished product. However the results related to surfactant concentrations must be confirmed with additional experiments in order to obtain a more precise view of the behavior of polyurethane foam as a function of the amount of surfactant used.

Date	2 May 2018
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Éric David (Supervisor) & Patricia I. Dolez (Co-supervisor)