USE OF LINEAR DIOLS FOR THE PRODUCTION OF BIOSOURCED POLYESTER FOAMS

The invention relates to a process for the production of a thermoset polyester foam, comprising the following steps in succession: (a) heating an essentially anhydrous pre-oligomerisation composition containing - a polyol component which contains at least 70% by weight, preferably at least 80% by weight, of a mixture of at least one hydrogenated sugar and at least one diol selected from the C3-6 diols, - a polyacid component containing a porogenic polyacid, preferably citric acid, and optionally - a catalyst, at a temperature between 100°C and less than 160°C for between 10 and 60 minutes, preferably between 15 and 40 minutes, under mechanical agitation, so as to cause the polyol component to react with the polyacid component and form a composition of oligomeric esters, (b) incorporating a surfactant composition into the oligomeric ester composition so as to obtain a thermosetting expandable composition, (c) introducing the thermosetting expandable composition that was obtained into a mould or applying said thermosetting expandable composition to a substrate, and (d) heating the thermosetting expandable composition to a temperature at least equal to 165°C in order to form a thermoset polyester foam.