A novel synthesis of polybutadiene-based polyurethane binder and conductive graphene–polyurethane nanocomposites: a new approach to polybutadiene recycling

Abstract

Synthesis and characterization of a new class of polybutadiene polyol polyurethanes were investigated with three consecutive reactions, namely polybutadiene (PB) chain cleavage by a two-step oxidation reaction using meta-chloroperbenzoic acid (m-CPBA) and periodic acid (H5IO6) in order to prepare polybutadiene polyol precursor, continued by telechelic amine polyol synthesis by an amination reaction using diethanolamine (DEA) in the presence of sodium borohydride (NaBH4) and finally telechelic polyurethane preparation by the reaction of synthesized polyol and toluene diisocyanate (TDI). Nanocomposites were prepared through an in situ polymerization reaction by incorporation of 1–3 wt% of graphene conductive nanosheets. Successful structural elucidation of the synthesized polymeric binder and nanocomposites was investigated by using well-known methods. TGA analysis revealed slower degradation and moderate thermal stability in higher weight percent nanocomposite. SEM images and XRD patterns resulted in fine nanoparticle distribution, lack of agglomeration and approximately constant nanoparticle size. Conductometry confirmed higher electrical conductivity data for nanocomposites by increasing graphene nanosheet contents.