Nanocomposite Reinforcement Effects in Millable Polyurethane Elastomer with Low Content of Halloysite Nanotubes

Abstract

Millable polyurethane / halloysite nanotubes nanocomposites with high tensile strength and elongation at break were prepared by adding halloysite nanotubes (HNTs) during the preparation of prepolymer. Tensile test revealed that the nanocomposites have both higher tensile strength and elongation at break. In particular, with only 1 wt % of halloysite nanotubes incorporated, an 1.17-fold increase in tensile strength and 0.58-fold increase in elongation at break were achieved, respectively. The halloysite nanotube hydroxyl is covalently bonded to the polyurethane molecular chain during the synthesis of the prepolymer, which is involved in the whole reaction, and thus to affect the degree of phase separation and hydrogen bonding between the segments of the polyurethane chain and the halloysite nanotube. In addition, the synthetic polyurethane elastomer nanocomposites owing a linear structure. This paper incorporated HNTs into the synthesis of MPU for the first time to stiffen and strengthen the material at very low loadings. Moreover, an unprecedented environmental no solvent prepolymer method in order to compound MPU / HNTs nanocomposites have been proposed.