Xiangfeng Wu

Morphology, Structure, and Crystallization of LaCl Modified Hollow Glass Microspheres/ Poly(vinylidenefluoride) Composites

Poly(vinylidene fluoride)/hollow glass microspheres (PVDF/HGMs) composites were prepared by using lanthanum chloride surface modified HGMs. The morphology, structure, and crystallization of the PVDF/HGMs composites were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC), respectively. The results showed that the interaction between the HGMs and the PVDF was improved by lanthanum chloride modification. The crystal structure of the PVDF was not changed by the HGMs, but the crystallinity was decreased. In addition, the Jeziorny and the Mo methods were used to analyze the non-isothermal crystallization kinetics. The results showed that the HGMs decreased the crystallization rates and extended the crystallization time of the PVDF.

Fabrication and Properties of Hollow Glass Beads Loaded Carbon Nanotubes/Epoxy Composites

Hollow glass beads loaded carbon nanotubes (HGB-CNT), prepared via an amidation reaction, were used for fabricating epoxy-matrix composites. The morphology of the as-prepared beads, and the tensile properties, electrical conductivity, and thermal behaviors of as-fabricated composites were evaluated. Field emission scanning electron microscopy and differential scanning calorimetry results showed that the dispersion of CNT in the matrix was improved as compared to control epoxy/HGB/CNT samples prepared using a conventional melt mixing method. Moreover, the tensile strength and elongation at break results illustrated that when CNT loading was 1.14 wt%, those of the epoxy/HGB-CNT composites were each ca. 25% more than the control samples. In addition, electrical conductivity results showed that when CNT loading was 1.59 wt%, the electrical conductivity of the epoxy/HGB-CNT composites increased by six orders as compared to that of the pristine epoxy and by four orders compared to that of the control samples.

Phase Structure, Thermal, and Mechanical Properties of Polypropylene/Hollow Glass Microsphere Composites Modified with Maleated Poly(ethylene-octene)

Maleated poly(ethylene-octene) (POE-g-MAH), as a compatilizer and toughener, was incorporated in polypropylene/hollow glass microspheres (PP/HGM) binary composites, and the phase structure and thermal and mechanical properties of these composites were investigated. Scanning electron microscopy analysis indicated that the phase structure of ternary composites could be controlled by POE-g-MAH and the surface treatment of HGM. Fourier transform infrared spectroscopy revealed that there was an amidation reaction between the treated HGM and POE-g-MAH during melt compounding. Differential scanning calorimetry suggested that the crystallization and melting behaviors of ternary composites were influenced by phase structure. Evaluation of mechanical properties showed that the amide linkage between the treated HGM and POE-g-MAH was favorable for improving the properties of ternary composites.

Effects of Soluble Cerous Compound as a Surface Modifier on the Properties of Isotactic Polypropylene/Hollow Glass Beads Composites

Cerous trinitrate hexahydrate was used as a surface modifier to treat hollow glass beads via a process of chemical deposition, and its effects on the strength, rheological, optical, and thermal properties of isotactic polypropylene/hollow glass beads(iPP/HGB) composites were assessed. The strength test results showed that the tensile strength and impact strength of iPP/HGB composites were obviously improved when HGB were modified, the optimum weight concentration of this modifier was 1.2 wt%. Moreover, dynamic rheological measurements showed that the complex viscosity and storage and loss moduli of the iPP/HGB composites were also increased when the HGB were treated. Additionally, the influences of this modifier on the structure and thermal properties, including the crystallizing and melting behaviors, of the composites were studied by means of X-ray diffraction, polarized optical microscopy, and differential scanning calorimetry. The results showed that the modifier had a nucleating effect on the matrix and promoted the formation of β-crystals of isotactic polypropylene.