Recently, bacterial polyester poly(hydroxybutyrateco-hydroxyvalerate) (PHBV) has been arising much attention in the field of biomedical and environmental friendly materials because of its good biocompatibility, biodegradability as well as thermoplastic properties. However, the wide application has been restricted by the poor mechanical properties and narrow processing window [1]. Therefore, a significant amount of work has been devoted to improving mechanical and thermal properties of PHBV via PHBV-based polymer blends and composites [2]. This work mainly covers four aspects: nanoparticles/PHBV composites, traditional petrochemicalbased materials/PHBV composites, biodegradable petrochemical-based polymer/PHBV composites, and bio-based materials/PHBV composites. In nanoparticles/PHBV composites, inorganic nanoparticles mainly include oxide [3], nitride [4], mineralization materials [5,6], carbon materials or minerals [7], and layered double hydroxides [8,9]. Organic nanoparticles mainly include cellulose nanocrystal [10], chitosan nanocrystal and starch nanocrystal [11]. The introduction of nanoparticles is helpful for improving the physical properties and processing properties of PHBV through increasing the nucleation density and decreasing the spherulite size. In petrochemical-based materials/PHBV composites, the additive components consist mainly of non-biodegradable polyolefin [12] Abstract. Full biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) composite films were prepared with 5~40 wt% green tea polyphenol (TP) as toughener. The effects of mixing TP on mechanical properties, thermal properties and hydrophilic-hydrophobic properties of composite films were investigated. Tension test results show that the incorporation of TP in the PHBV matrix can enhance the toughness of the composite films. Differential scanning calorimetric (DSC) studies show that there is a single glass transition temperature and the lower melting point temperature. Fourier transform infrared (FT-IR) results confirm that the intermolecular hydrogen bonding interactions in composite films. Contact angle measurements show that the hydrophilicity of TP/PHBV composite films can be controlled through adjusting the composition of TP.

Polyamide 6 (PA6), a commercially important semicrystalline polymer, is widely used in engineering plastics, film and fibers [1][2][3][4], which usually causes fires and consequently leads to huge loss of human lives and property, which, to a certain degree, limits the range of applications. We demonstrate a novel strategy to improve the flame-retardant properties of PA6 by using reduced graphene oxide decorated with halloysite nanotubes (HNTs-d-rGO) hybrid composite. Graphene, exhibiting outstanding electronic, mechanical [5][6][7][8] and thermal [9,10] properties, is emerging as a rising star in the field of flame-retardant applications due to its endothermic and stable structure [10][11][12][13]. For example, the peak heat release rate (PHRR) of polyvinyl alcohol (PVA) filled with graphene is reduced by 49% [11]. However, in order to achieve fire resistance, the content of graphene used as flame retardant in polymer should be relatively high. Besides, nanocomposites consisting of polymer and clay, such as montmorillonite and kaolinite, are widely used to improve the flame-retardant properties of polymers [14,15]. Halloysite nanotubes (HNTs), one kind of nanoclay, have attracted research attention as fillers for polymer nanocomposites due to their improvement of mechanical [16,17] Abstract. The improvement of flame-retardant properties of polyamide 6 (PA6) was achieved by using reduced graphene oxide decorated with halloysite nanotubes (HNTs-d-rGO) hybrid composite as the additive in PA6 matrix. The intimate integration of reduced graphene oxide (rGO) and halloysite nanotubes (HNTs) through a three-step chemical functionalization, enabled the combination of their unique physical and chemical characteristics together. The nanostructure of HNTs-drGO was determined by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). A morphological study revealed that HNTs-d-rGO was dispersed uniformly in PA6 matrix. From the results of cone calorimetry measurements, the fire retardant properties of PA6 were further improved with the addition of HNTs-d-rGO when compared with that of either HNTs, or GO, or a mixture of HNTs and GO (HNTsm-GO) used in PA6 matrix. The results indicate clearly that higher flame-retardant activity of the integrated HNTs-d-rGO nanostructures than that of the simple mixture verifies the importance of the intimate integration between HNTs and rGO, which ascribe to the combination of the stable silica layer created by HNT and the barrier effect of rGO.