Composition comprising: a) at least one polymer chosen from the group consisting of a polyether comprising two terminal functions of silane type, a polyurethane comprising two terminal functions of silane type, a polyamide, or a mixture thereof; b) a plasticizer; c) at least one compound selected from the group consisting of a thickener, a filler, a crosslinking agent, a crosslinking catalyst and a tackifying resin, or a mixture thereof, said plasticizer comprising: i) at least one hydrocarbon cut or a cut resulting from the conversion of biomass, said cut being able to be produced from raw biological materials selected from the group consisting of vegetable oils, animal fats, fish oils and mixtures thereof, the raw biological materials undergoing a hydrodeoxygenation step to decompose the structure of the constituent biological esters or triglycerides and to remove the compounds containing oxygen, phosphorus and sulfur while at the same time producing the hydrogenation olefinic bonds, followed by isomerization of the product thus obtained leading to branching of the hydrocarbon chain, ii) at least one fatty acid monoester, the fatty acids of the fatty acid monoester comprising from 6 to 24 carbon atoms; iii) less than 1% by weight of phthalates. a) at least one polymer chosen from the group consisting of a polyether comprising two terminal functions of silane type, a polyurethane comprising two terminal functions of silane type, a polyamide, or a mixture thereof; b) a plasticizer; c) at least one compound selected from the group consisting of a thickener, a filler, a crosslinking agent, a crosslinking catalyst and a tackifying resin, or a mixture thereof, said plasticizer comprising: i) at least one hydrocarbon cut or a cut resulting from the conversion of biomass, said cut being able to be produced from raw biological materials selected from the group consisting of vegetable oils, animal fats, fish oils and mixtures thereof, the raw biological materials undergoing a hydrodeoxygenation step to decompose the structure of the constituent biological esters or triglycerides and to remove the compounds containing oxygen, phosphorus and sulfur while at the same time producing the hydrogenation olefinic bonds, followed by isomerization of the product thus obtained leading to branching of the hydrocarbon chain, ii) at least one fatty acid monoester, the fatty acids of the fatty acid monoester comprising from 6 to 24 carbon atoms; iii) less than 1% by weight of phthalates. i) at least one hydrocarbon cut or a cut resulting from the conversion of biomass, said cut being able to be produced from raw biological materials selected from the group consisting of vegetable oils, animal fats, fish oils and mixtures thereof, the raw biological materials undergoing a hydrodeoxygenation step to decompose the structure of the constituent biological esters or triglycerides and to remove the compounds containing oxygen, phosphorus and sulfur while at the same time producing the hydrogenation olefinic bonds, followed by isomerization of the product thus obtained leading to branching of the hydrocarbon chain, ii) at least one fatty acid monoester, the fatty acids of the fatty acid monoester comprising from 6 to 24 carbon atoms; iii) less than 1% by weight of phthalates.