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In this study, the reinforcement effects of graphene on the properties of bio-based polyurethane (PU) were studied with the use of 1 wt% three functionalized graphene (dispersible graphene, reduced graphene oxide-NH 2 , and reduced graphene oxide-tetraethylene pentamine). Scanning electron microscope (SEM) revealed the relatively homogeneous dispersion of graphene nanoplatelets in the PU matrix. It was found that the addition of 1 wt% of the different graphenes could lead to a significant reinforcement effect on the bio-based PU. Especially, PU nanocomposite with 1 wt% dispersible graphene exhibited 6°C improvement in the T g , 75% increment in storage modulus at 25°C, 34% increase in tensile strength, and 30% increase in Young's modulus.Practical applications: Different graphene were used to reinforce the bio-based PU. A significant reinforcement effect of graphene on bio-based PU was found. This strategy has the potential for the fabrication of advanced bio-based materials.

A convenient one-pot synthesis of linear-hyperbranched polyphosphoesters (l-HBPPEs) was accomplished by a tandem ring-opening metathesis polymerization (ROMP) and acyclic diene metathesis (ADMET) polymerization procedure. A linear monotelechelic poly(norbornene) with a terminal acrylate and many pendent thiol groups is first prepared through adding an internal cis-olefin terminating agent to the reaction mixture immediately after the completion of the living ROMP, and then utilized as a macromolecular chain stopper in subsequent ADMET polymerization of a phosphoester functional AB 2 monomer, yielding l-HBPPEs as the reaction time prolonged. These l-HBPPEs bearing lots of pendent thiol groups in linear poly(norbornene) and peripheral acrylate groups in HBPPE could be self-crosslinked in ultradilute solution through thiol-Michael addition click reaction between acrylate and thiol to give single-molecule nanoparticles with comparatively uniform size. This facile approach can be extended toward the fabrication of novel nanomaterials with sophisticated structures and tunable multifunctionalities. V C 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 964-972