Polyisoprene as a useful substrate dedicated to new polymer developments; from natural rubber to bioactive polymers
Résumé
A review. The past decade has seen increased research activity devoted to the development of environmentally friendly methods for producing polymers. Indeed, the possibility of obtaining polymers from naturally occurring sources such as polysaccharides or polyisoprene rubber is of great interest from both economic and environmental points of view since these processes are less reliant upon petrochem. precursors. Methods for producing a range of polymers that have specific phys. or biol. properties tailored to suit a particular application are still required and so research in our lab. is focused towards developing methods for the synthesis of different polyisoprene based polymers. These polymer products are obtained from the controlled degrdn. of high mol. wt. polyisoprenes either through oxidative cleavage of the isoprene units or by metathesis using Grubbs catalyst. The telechelic liq. rubber subsequently produced has a well defined microstructure that has been characterized by std. techniques, and a low polydispersity index. Furthermore, the resulting polymer can be chem. modified in order to produce polymers contg. a range of chem. functionalities. As an example, hydroxytelechelic precursors can be degraded in a controlled fashion to produce polyurethanes or photocrosslinkable polymers and evaluation of the mech. and physico-chem. properties has demonstrated that these materials could be an effective substitute for analogous std. polymers for diverse applications such as phonic insulation polymers, coatings and foams. Moreover, these polyisoprene based polymers may exhibit specific activity towards pathogenic bacteria. This biol. activity is related to a bacteriostatic (immobilization of bacteria) and antifouling effect of the polymer surface. In this paper we firstly report a no. of novel chem. modifications recently performed on oligo-isoprene in our lab., and secondly the properties assocd. with each of a series of polyisoprene based polymers and polyurethanes that have been synthesized are described.