| abstract |
The present invention relates to a compound of formula (I): n n n n n n n n n n in which: the R 1 and R 2 groups, which may be identical or different, are, independently of one another, a saturated or unsaturated, linear, branched or cyclic hydrocarbon group having from 1 to 15 carbon atoms, preferably from 1 to 10 carbon atoms; the R 3 and R 4 groups, which may be identical or different, are selected, independently of one another, from a hydrogen atom, a methyl group or an ethyl group; the R, R 6 and R 7 groups, which may be identical or different, are selected, independently of one another, from a hydrogen atom or an alkyl group comprising from 1 to 6 carbon atoms; n is an integer of 0 to 20; and m is an integer of 1 to 6. |