Abstract: The invention relates to a method for preparing a polyester polymer material, which comprises preparing a reaction medium comprising a mixture of at least one monomer chosen from ?-hydroxylated fatty acids and ?-hydroxylated fatty acid esters of an alcohol comprising an aliphatic chain comprising from 1 to 18 carbon atoms, and at least one phenolic compound, the total content of phenolic compound(s) being within a range of values from 0.3 to 42 mg equivalent of gallic acid per gram of the mixture. The method then comprises heating this reaction medium in order to carry out the polymerisation of the monomer and the phenolic compound and the cross-linking of the polymer thus formed.

Abstract: A method for preparing a polymer of the elastomer type based on a monomer selected from polyhydroxylated fatty acids and esters of a polyhydroxylated fatty acid and a C1-C18 aliphatic chain alcohol is disclosed. This method includes preparing a reaction medium by bringing the monomer with a polyol, this reaction medium being catalyst free, then a step of heating the reaction medium in order to implement the copolymerisation of the monomer and of the polyol and the cross-linking of the polymer thus formed, with at least the initial phase of this heating step being implemented at a reduced pressure.

Abstract: The invention relates to an isolated plant GDSL-lipase polypeptide differentially expressed between the different steps of the plant development and/or the different tissues of the plant, a nucleic acid molecule encoding it, and a plant or part of plant genetically engineered to not express it at least partially.