Modification au deuxième degré de polymères époxydés, 1. Etude sur molécules modèles des polyalcadiènes

Abstract

The addition of benzoic acid to the oxirane ring ofmodel compounds for epoxidized polymers ofdienes was studied. A convenient reaction rate was observed for temperatures of about 100 "C. It was found that the addition reaction can be catalysed by basic compounds. Kinetic studies showed the influence of solvent nature, of concentration of reagents, of catalysts, and of the epoxide structure. The reactivities of various acids showing particular properties (drugs, UV-absorbers, herbicides) were investigated. Partie experimentaleLa synthese des modeles epoxydes a ete realisee selon la methode prectdemment decrite"? Dans certains cas (ethyl-3 pentene-i, principalement) l'acide monoperphtalique a ete remplace par l'acjde metachloroperbenzoique en solution dans le chlorure de methylene, afin d'ameliorer les rendements. Les produits obtenus ont ete isoles des acides presents dam le milieu reactionnel par distillation sous vide sur paroi froide, sur evaporateur rotatif, puis redistilles sur colonne a bande tournante.

Chemical modification of polydienes in latex medium: Study of epoxidation and ring opening of oxiranes

“…The reactivity of nucleophilic reagents toward epoxidized 1,4‐polyisoprene latexes was studied. The objective was to determine whether the nucleophilic reagents that were shown to be able to add onto the epoxidized units of epoxidized rubbers in solution5–10 could also react with the same polymers in latex conditions. The study was achieved with ENR latexes, but also with ELIR latexes coming from LIR‐700 latex, a synthetic rubber latex prepared by emulsification of a synthesized 1,4‐polyisoprene.…”

“…ELIR latexes were considered to be models of ENR latexes. The compositions of modified rubbers obtained in latex medium were determined by comparison with that of the phosphorated rubbers prepared in solvent 5–10. After a preliminary study performed with various nucleophiles to verify their ability to react onto epoxidized rubbers in latex medium, a systematic study was achieved with DBP, which was shown to be very reactive in these conditions.…”

“…This modification is important due to the great reactivity of oxirane rings toward nucleophilic reagents. For example, reactions with amine,5 carboxylic acid,6, 7 alcohol,8, 9 and phosphoric acid derivatives,10, 11 have been studied on epoxidized polyisoprene in solution.…”

Chemical modifications of polydiene elastomers: A survey and some recent results

“…If LNR can be compared to synthetic liquid 1,4-polyisoprene and used in the same field of applications, it may be useful to use LNR as starting product for preparation of specific polymers for highly technical applications through judicious chemical modification. 50 It is the same for ELNR, whose reactivity of the epoxide groups toward carboxylic acids, 51,52 amines, 53,54 phosphoric acid derivatives, 55 and alcohols 56 is well known (Fig. 10).…”

Base‐Induced Sequential Cyclization–Rearrangement of Enantioenriched 3‐Aminoalkanoates to Five‐ and Seven‐Membered Lactams

“…Ring opening of epoxidized units under neutral and mild conditions generally requires the use of a catalyst. Thus, addition of acids and amines to oxirane rings of epoxidized polyisoprenes is conveniently catalyzed by onium salts,1, 7 Brönsted acids and phenolic acids 3, 8–10. However, no catalyst is used in the case of phosphate acid derivatives which provide acidic protons by self‐dissociation equilibrium 6…”