Powder coating for dry coating technique of paper as the promising method has attracted more and more attentions in recent years due to its advantages in reducing the dosage of water and saving energy compared with conventional coating. This study focused on the in situ polymerization of methyl methacrylate (PMMA) under a water-free condition in supercritical carbon dioxide in the presence of inorganic kaolin. The effects of varying the concentrations of the monomer, initiator, and stabilizer on the molecular weight and morphology of the resultant PMMA were investigated and discussed. Then the powder coating was systematically evaluated and characterized by gel permeation chromatography, scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Meanwhile, the feasibility of manufacturing PMMA/kaolin powder coatings was explored, and the mechanism of polymerization and the thermal degradation kinetics of powder coating were studied. The experimental results showed that the properties of PMMA as a film former were suitable with the molecular weight and narrow molecular weight distribution close to that in conventional coating when the concentration of monomer was about 10 wt %, concentration of initiator ∼1–1.5 wt % and stabilizer about 10 wt % with respect to monomer. Moreover, the interfacial bonds and dispersion situation of polyacrylic ester-based water-free powder coating particles were fairly well, the powder coating possesses good film-forming property combined with outstanding thermal-stability performance. The combination of these characteristics makes PMMA/kaolin powder coating an excellent candidate for dry coating technique of paper applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42439.

Reversible light-responsive nanogels were constructed from an amphiphilic spiropyrane-modified pullulan (SpP). The polymer was synthesized by modifying a biodegradable pullulan with carboxyl-containing spiropyrane (Sp) molecules. The SpP structure was confirmed by the appearance of a carbonyl signal in the FT-IR and ¹H NMR spectra. The nanogels can be controlled by photostimulation, which results in the reversible structural transformation of the hydrophobic Sp to the hydrophilic merocyanine. The physical properties of the nanogels were confirmed to change dramatically after being irradiated with different wavelengths of light. Drug delivery tests showed that the model drug pyrene was completely captured by the nanogels and then released from the SpP nanogels in a light-dependent manner. This study provides an alternative approach to constructing light-responsive nanocarriers with excellent biocompatibility for drug uptake and release. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40288.

Heat-sealing properties are necessary for packaging materials. Soy protein isolate/polyvinyl alcohol (SPI/PVA) blend film is a biodegradable potential packaging material. We analyzed the effects of PVA content (0–20%), glycerol content (1–3%), and sealing temperature (180–230°C) on the heat-sealing properties of SPI/PVA blend film. Results showed that SPI/PVA film obtained the desired sealing properties when the PVA content exceeded 15%. The sealing strength increased with the PVA content, reaching a maximum upon blending with 20% PVA and 1% glycerol at 220°C. The temperature at sealing strength was approximately twice that at 180°C. However, glycerol migrated to the surface and hindered the entanglement of macromolecular chains in the sealing interface, thereby resulting in reduction of seal strength. Glycerol vaporization at 204°C led to aesthetically unacceptable blistering in the sealing area. Therefore, the optimum sealing temperature of the blended film was ∼200°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40308.