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The good oxygen barrier and hydrophobic properties of curdlan (CL) film might be suitable complements for MC film, and its similar glucose unit and thermal-gel character might endow the methyl cellulose (MC)/CL blended system with compatibility and good comprehensive properties. Thus, MC/CL blended films were developed. The effects of MC/CL blend ratios on the microstructures and physical properties of the blends were characterized by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), oxygen and water vapor permeability testing, dynamic mechanical analysis (DMA), light transmittance testing, tensile testing, hydrophilic property testing, and water solubility testing. The introduction of CL affected the molecular aggregation and crystallization of the MC molecules, suggesting MC–CL molecular interactions. The cross-sectional roughness of the MC/CL film increased with an increase in CL content, while the surface of the MC/CL 5:5 film was smoother than those of the MC/CL 7:3 and 3:7 films. Only one glass transition temperature, which was between that of the MC and CL films, was observed for the MC/CL 7:3 and MC/CL 5:5 films, indicating the good compatibility of the MC and CL molecules at these two blend ratios. The hydrophobicity and water insolubility increased with the CL content, which was due to the combined effects of more hydrophobic cavities in the CL triple-helix and increased surface roughness. Increased oxygen barrier properties with increasing CL content might be a combined effect of the increased hydrogen bonds and hydrophilic ektexines of the CL triple-helix. The elongations of the blended films were higher than those of the MC film, which might be related to its increased water content. The MC/CL 7:3 and MC/CL 5:5 films retained the good light transmittance and tensile strength of the MC film, which corresponded well to their good compatibility and might be due to the effects of the MC–CL molecular interactions and the relative smooth morphologies. MC/CL 5:5 showed improved water vapor barrier properties, which might be due to its smooth surface morphologies. This research offers new MC based films with improved properties and good compatibility, providing great potential for use as edible coatings, capsules, and packaging materials. [ABSTRACT FROM AUTHOR]

This work focuses on the effect of curdlan (CL) on dynamic viscoelastic property, thermal reversible property, viscosity, and the fluid types of hydroxypropyl methylcellulose (HPMC) at different temperatures. Compared to the blends at 25 °C, the blends had a smaller linear viscoelastic region (LVR), a higher gel strength, and larger storage modulus (G') and loss modulus (G") values at 82 °C. G', G", gel strength, and viscosity increased with the increase of CL. Repeated temperature sweep led to increased G' and G" of HPMC/CL blends. For HC6 and HC8, the gel formation temperature of the repeated temperature sweep was significantly lower than that of the first sweep. The samples at 82 °C, except for the sample with 8% CL, were all yield-shear thinning fluids, and the samples at 40 °C were shear thinning fluids. The creation of HPMC/CL and its rheological research might provide some methodological references for the study of other thermal–thermal gel blends. [ABSTRACT FROM AUTHOR]

Hydroxypropyl methylcellulose (HPMC)/sodium citrate (SC)/lipid tea polyphenol (LTP) photophobic films with different pore sizes from micron scale to nanometer scale were prepared by regulating the SC content (1–7%). The microstructures, physical and sustained antioxidant properties of these films were studied by using wide angel X-ray diffraction, small angle X-ray scattering (SAXS), scanning electron microscope, whiteness meter, ultraviolet spectrophotometer, texture analyzer and peroxide value test. Composite films with higher SC content showed larger pore size and whiteness. With the increasing SC content, crystallinity first increased then decreased. The addition of SC decreased the D s (surface fractal dimension) value, smoothness of the cross-section structure, tensile strength, elongation and modulus of composite films. HPMC/SC/LTP microporous films possessed control-release property in oil system, reflected by the lowest peroxide value of peanut oil enclosed in film with 3% SC during three weeks, meaning this film showed the best sustained antioxidant property. [ABSTRACT FROM AUTHOR]

Photophobic (white) films were prepared with hydroxypropyl methylcellulose (HPMC) and monosodium phosphate (NaH 2 PO 4 ) to overcome the redox reaction induced by titanium dioxide photocatalysis of HPMC/TiO 2 white film. What’s more, HPMC/NaH 2 PO 4 white film could overcome the drying temperature dependent property of white films based on HPMC and calcium salts. Attenuated total reflection Fourier transform infrared spectroscopy, wide angel X-ray diffraction, small angle X-ray scattering, scanning electron microscope and texture analyzer were used to investigate the effect of NaH 2 PO 4 on the short-range, supra-molecular structures and properties of HPMC film. The formation mechanism of the white film was speculated by analyzing the structures of different scales. The results showed that the interaction might happen between H 2 PO 4 −1 group of NaH 2 PO 4 and CH, CH 2 and CH 3 group of HPMC. These interactions influenced the polymer chain movement and combination and further affected the aggregation structures. Specifically, the compactness, smoothness and scale range of the surface fractal scatters in films increased and elongated particles of two scales appeared. These changes of ordered structure in the micro-region might contribute to increasing the reflected light and decreasing the transmission light of films, resulting in white films with photophobic property. The addition of NaH 2 PO 4 decreased the crystallinity and smoothness of the cross-section of HPMC film, which resulted in a little lower tensile strength, elongation and elastic modulus of HPMC/NaH 2 PO 4 films. Films of less than 10% of NaH 2 PO 4 showed similar mechanical properties with pure HPMC film, which offered proper parameters for the production of HPMC/NaH 2 PO 4 photophobic films in the application. [ABSTRACT FROM AUTHOR]

Different ionic liquid (IL)s were added to hydroxypropyl methylcellulose /monosodium phosphate (HPMC/MSP) photophobic film to improve its ductility, and their effects on its multi-scale structures and physical properties were studied. After adding these ILs, smoothness of the fractal structure, tensile strength, modulus of the film did not change obviously, while the crystallinity, the number of holes, and elongation increased, the hole size and T g decreased. Compared to films with other ILs, the film with 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF 4) showed the largest elongation and crystallinity, the smallest hole size, the least holes, and highest whiteness. The film with 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) showed the largest water content and the lowest T g. The increased elongation proved that all these ILs could improve the ductility of the film, among which, [EMIM]BF 4 had the strongest plasticizing effect. [ABSTRACT FROM AUTHOR]

Photophobic (white) films were prepared by mixing hydroxypropyl methylcellulose (HPMC) of different molecular weights with sodium citrate (SC). Wide angle X-ray diffractometry, small angle X-ray scattering, scanning electron microscopy, dynamic mechanical analysis, whiteness determination and texture analysis were used to investigate the effect of HPMC molecular weight on the aggregation structures and properties of HPMC film. The crystalline integrity decreased with the increased molecular weight of HPMC for these HPMC/SC films. Similar crystallinity was observed for 6HPMC/SC and 15HPMC/SC, which was larger than that of 50HPMC/SC. All the three HPMC/SC film showed surface fractal structure with similar D s. With the increasing molecular weight of HPMC, the HPMC/SC film showed honeycomb structures with smaller holes and more compact porous structure, T g first increased and then decreased a little, the tensile strength and elongation increased with the increasing HPMC molecular weight. 50HPMC/SC films with the smallest pores showed the largest whiteness. A new T g ' peak was observed for HPMC/SC film. • Effect of HPMC molar mass on structural properties of HPMC/SC films was studied. • The HPMC/SC film with higher HPMC molar mass showed smaller and more compact holes. • The tensile strength and elongation increased with the increasing molar mass of HPMC. • 50 HPMC/SC films with the smallest pores showed the largest whiteness. • New T g ′ peak was observed for HPMC/SC film, with the most obvious for 6 HPMC/SC film. [ABSTRACT FROM AUTHOR]

Abstract Monosodium phosphate (MP), sodium citrate (SC), sodium lactate (SL) and magnesium citrate (MC) can be blended with hydroxypropyl methylcellulose (HPMC) to make photophobic (white) films at lower drying temperatures. Small angle X-ray scattering (SAXS), wide angle X-ray diffraction (XRD), scanning electron microscopy (SEM), whiteness determination, dynamic mechanical analysis (DMA) and texture analysis were adopted to study the variation of microstructures and properties. These four kinds of HPMC/salt films showed decreased crystallinity and increased compactness and smoothness of the self-similar structures in larger scale ranges. HPMC/MP, HPMC/SC and HPMC/SL film showed coarser and porous morphologies, lower mechanical parameters and higher whiteness than pure HPMC film. HPMC/MC film showed smoother morphologies, higher tensile strength, elongation and whiteness than pure HPMC film. Porous structures and more compact self-similar structures might contribute to the photophobic property of these films, and relatively smooth morphology might dominate the increasing mechanical parameters of HPMC/MC film. [ABSTRACT FROM AUTHOR]

Hydroxypropyl methylcellulose (HPMC) and curdlan (CL) were used to prepare uniform films. The influence of the composition ratios and drying temperature on the microstructures, compatibility and physical performance of HPMC/CL films were studied. The crystalline peaks corresponding to CL component of HPMC/CL films increased with the increasing CL content. Increasing CL content resulted in increased hydrogen bonds in HPMC/CL film, reduced transmittance at 500 nm, oxygen permeability and water solubility of the HPMC/CL films. Higher drying temperature led to increased phase separation and decreased physical properties of pure HPMC film, and led to increased compatibility, cross-section smoothness, oxygen barrier property and mechanical properties of pure CL and blending films. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ductility increased with the increase of [EMIM]Ac. • The pore size and pore number can be regulated by changing the [EMIM]Ac content. • After adding [EMIM]Ac, the film still kept good photophobic property. • The improved films have potential to be used as packaging for light sensitive foods. X-ray diffraction, small angel X-ray scattering, scanning electron microscopy, moisture determination, dynamic mechanical analysis, whiteness assay and mechanical testing were used to study the effects of different doses of [EMIM]Ac on the microstructures and physical properties of HPMC/MSP film. By adjusting the 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) content (0 %–8 %), the mechanical properties and microstructures could be regulated. The elongation of the film increased from 5.91 % to 12.83 % with the increasing [EMIM]Ac content from 0% to 8% without affecting the tensile strength and modulus significantly. The average pore area decreased from 0.82 μm2 to 0.05 μm2 and the pore number increased with the increasing [EMIM]Ac content from 0% to 8%. Moreover, with the increasing [EMIM]Ac content, T g decreased. 6% and 8% [EMIM]Ac decreased the compactness and smoothness of the fractal structure of the film greatly. [EMIM]Ac improved the ductility of HPMC/MSP film, which was mainly due to the decreased pore size and T g. The improved photophobic films are both flexible and with easily changeable porous structure, which can be used as controllable packaging to carry and control-release different functional agents for different light sensitive foods. [ABSTRACT FROM AUTHOR]