Referring to previous work carried out in organic solvents, a study of the action of nucleophilic reagents on epoxidized units of 1,4-epoxidized polyisoprene (synthetic polyisoprene or natural rubber) was performed in latex medium. Among the considered reagents, dialkylphosphate and ammonium diethyldithiophosphate demonstrated the ability to add under these reaction conditions on epoxidized units according to a SN2 substitution with an oxirane ring-opening mechanism. A systematic study was performed with dibutylphosphate that was shown to be very reactive. Grafting of phosphorated groups along polyisoprene chains was carried out via reaction of the acidic function (P-OH) of the phosphate with oxirane rings previously created on a 1,4-polyisoprene backbone. The prominent role of latex pH on the reaction was shown.

ABSTRACT:The synthesis of 1,4-polyisoprenes bearing organophosphorated groups in the side positions of polydiene chains was considered with a chemical modification procedure. The grafting of phosphorated groups along polyisoprene chains was carried out via the reaction of the acid functionality (POOH) of phosphate or phosphonate acid reagents with oxirane rings previously created on a 1,4-polyisoprene backbone. The reagents considered were dibutylphosphate and 2-chloroethylphosphonic acid. The purpose was to compare the action of these two reagents toward epoxidized units of 1,4-epoxidized polyisoprenes in various media (solvent, bulk, and latex).