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Polylactide (PLA)-recycled wood fiber (RWF) composites with a small amount of silane were compounded using a kinetic-mixer and molded using an injection molding machine. The molded PLA-RWF compo- sites were characterized using gel permeation chromatog- raphy, scanning electron microscope, X-ray diffraction, differential scanning calorimeter, tensile testing machine, and a dynamic mechanical analyzer. As observed in the stress-strain plots, the amount of necking before fracture decreased with an increasing RWF content. Similarly, the strain-at-break also decreased with the RWF content. The tensile strength remained the same irrespective of the RWF content. Both the tensile modulus and the storage modulus of the PLA-RWF composites increased with the RWF content. The degree of crystallinity of the PLA increased with the addition of RWF. No reduction in the number-average molecular weight (Mn) was observed for pure PLA and PLA-10%RWF-0.5%Silane composites af- ter injection molding; however, substantial reduction in Mn was found in PLA-20%RWF-0.5%Silane composites. Finally, a theoretical model based on Halpin-Tsai empiri- cal relations is presented to compare the theoretical results with that of the experimental results. V C 2008 Wiley Periodi

Microwave-assisted ring-opening polymerization (MROP) of trimethylene carbonate (TMC) was carried out with four different types of zinc lactate, as the catalyst. Poly(trimethylene carbonate)s (PTMC) with a number–average molar mass ranging from 2990 to 75,410 g/mol and a TMC conversion ranging from 85.2% to 98.2% were synthesized effectively in 30 min at 120°C under microwave irradiation. The effects of the catalyst type, catalyst concentration, and microwave irradiation time on the MROP of TMC were studied. The MROP of TMC was much faster than that under conventional heating conditions. Thermal analysis suggested that PTMC with higher molar mass exhibited higher glass transition temperature (Tg) and thermal stability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

New amphiphilic polymer networks were synthesized by the free-radical copolymerization of α,ω-diacryl polycaprolactone (DAPCL) and N-vinylpyrrolidone (NVP), which was initiated by 0.5% azobisisobutyronitrile at 70°C. The chemical structures of the networks were characterized by proton nuclear magnetic resonance spectrometry. The NVP/DAPCL feed ratio played an important role in the crosslinking process. The synthesized amphiphilic polymer networks exhibited controlled swelling properties in water and organic solvents (ethanol, acetones, and toluene). A porous structure was observed for the amphiphilic polymer networks under a scanning electron microscope. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

This article presents the development and characterization of transparent poly(styrene-r-maleic anhydride) (SMA)/alumina nanocomposites for potential use in optical applications. Chemically treated spherical alumina nanoparticles were dispersed in an SMA matrix polymer via the solution and melt-compounding methods to produce 2 wt % nanocomposites. Field emission scanning electron microscopy was used to examine the nanoparticle dispersion. When the solution method was used, nanoparticle reagglomeration occurred, despite the fairly good polymer wetting. However, through the coating of the alumina nanoparticles with a thin layer (ca. 20 nm) of low-molecular-weight SMA, reagglomeration was absent in the melt-compounded samples, and this resulted in excellent nanoparticle dispersion. The resultant nanocomposites were semitransparent to visible light at a 2-mm thickness with improved UV-barrier properties. Their impact strengths, tensile strengths, and strains at break were slightly reduced compared with those of their neat resin counterpart, whereas a small enhancement in their moduli was achieved. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007