SYNTHESIS AND CHARACTERISATION OF BIO-SOURCED COPOLYMERS CONTAINING MYRCENE AND CONJUGATED DIENE INITIATED BY NEODYMIUM-BASED COORDINATION CATALYSTS

Abstract

Myrcene is a promising alternative to petroleum-based materials. This conjugated terpene, found in many essential oils, has the potential to be used as a source material for producing elastomers derived entirely from biosourced materials. It could serve as a substitute for polymers like polybutadiene and other types of petroleum-based polymers. At 70 °C in toluene, a copolymer poly(1,4-trans-myrcene-co-styrene) and polymyrcene-block-polyisoprene are created using neodymium trisborohydride Nd(BH₄)₃(THF)₃ in combination with n-butylethyl magnesium (C₂H₅MgC₄H₉). The use of this catalytic system for the statistical copolymerization of myrcene-styrene is a highly efficient method that leads to the production of a copolymer with excellent stereoregularity and a high yield. Nd(BH₄)₃(THF)₃/C₂H₅MgC₄H₉ is also effective in the production of block copolymers (myrcene-isoprene). These resulting copolymers consist of an isoprene content of approximately 41 % and show no significant change in polymyrcene stereoselectivity despite the presence of a significant amount of isoprene. Additionally, the incorporation of myrcene into the copolymers makes it possible to soften the trans-isoprene polymer. Therefore, this catalytic system provides a valuable and promising method for synthesizing copolymers that serve as interesting precursors for biosourced elastomers.