Center for Polymer from Renewable Resources

Guangzhou, China

Center for Polymer from Renewable Resources

Guangzhou, China
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Meng L.,Center for Polymer from Renewable Resources | Meng L.,Sino Singapore International Joint Institute | Liu H.,Center for Polymer from Renewable Resources | Yu L.,Center for Polymer from Renewable Resources | And 5 more authors.
Journal of Applied Polymer Science | Year: 2017

Biodegradable elastomer poly[(1,4-butylene terephthalate)-co-(1,4-butylene adipate)] foam was successfully prepared using supercritical CO2. The elastomer foam has closed and uniform cell structure with density about 90 g/L. Narrow size distribution with average cell diameter 32 μm were obtained. The foamed balls show rubbery properties and can recover well (>90%) to their original shape quickly after releasing press stress. Cell growth needs to take place at melting state where the migration and orientation of polymer chains are permanently kept without remained force of springback. Some unique phenomena were observed during foaming the elastomer: post-expansion (about 40%) was obtained after removing the foamed samples from a cylinder mold, which results in forming a ball rather than a cylinder like the mold. This phenomenon was explained by the lower glass transition temperature of the elastomer, in which residual CO2 foam continuously in the room temperature; and “memory” of internal strength. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44354. © 2016 Wiley Periodicals, Inc.


Ali A.,Center for Polymer from Renewable Resources | Yu L.,Guangzhou University | Liu H.,Center for Polymer from Renewable Resources | Khalid S.,Center for Polymer from Renewable Resources | And 2 more authors.
Journal of Applied Polymer Science | Year: 2017

Biodegradable films, with starch as a matrix, were developed and reinforced with wheat and corn hulls. The effect of the particle size of the filler on the microstructure and mechanical and barrier properties of starch-based films was investigated. We observed that the addition of hulls enhanced the modulus, tensile strength, and impact strength of the starch matrix at the expense of its elongation. The water-vapor transmission rate results show that corn starch was more efficient in reducing the water-vapor permeability than wheat hulls. Scanning electron microscopy observations indicated that the compatibility of both fillers with the matrix was quite good; this was expected because all of the components used in this study were hydrophilic and exhibited polar behavior. Optical microscopy and X-ray diffraction observations indicated that the processing conditions did not affect the crystalline and geometric structures of the hulls. Because all of the components used in this study were from food resources, the films could also be used for edible packaging. © 2017 Wiley Periodicals, Inc.


Zhang L.,Center for Polymer from Renewable Resources | Zhang L.,CSIRO | Zhang L.,Monash University | Wang Y.,Center for Polymer from Renewable Resources | And 6 more authors.
Colloid and Polymer Science | Year: 2014

This work focuses on the study of rheological and gel properties of hydroxypropyl methylcellulose (HPMC)/hydroxypropyl starch (HPS) blends. It was found that both rheological properties in solution and gel behaviors in hydrogel of the blends depended on polymer/solvent concentration, HPMC/HPS ratio, and temperature. At higher temperature, all the blending samples showed hydrogel behavior, while at lower temperature, the suspensions with higher HPS ratio displayed hydrogel-like behavior but the gels were able to be destroyed at higher frequencies. With an increase of the HPS ratio, the fluid behavior index deceases, meaning the solution shows more obvious pseudoplastic behavior. However, the fluid consistency index increases, meaning that viscosity increases with increase of HPS content. The strength of HPMC gel was weakened by additional of HPS at higher temperature, while the HPS gel was weakened by addition of HPMC at lower temperatures. Viscosities of both HPMC and HPS were balanced by the blending at different temperatures since one is thermal and other is cool gel, which improves the processability for many applications. © 2014, Springer-Verlag Berlin Heidelberg.


Gao C.,Center for Polymer from Renewable Resources | Gao C.,Monash University | Gao C.,CSIRO | Meng L.,Center for Polymer from Renewable Resources | And 6 more authors.
Composites Science and Technology | Year: 2015

Uniaxial poly(lactic acid)-based self-reinforced composites have been developed by bonding poly ( l-lactic acid) (PLLA) fibers by depositing poly(D, l-lactic acid) (PDLLA) which was dissolved in ethyl acetate. The microstructure and the thermal and mechanical properties of this self-reinforced composite have been characterized using scanning electron microscopy, dynamic mechanical analysis, and tensile testing. The results revealed that after ethyl acetate treatment, the PLLA fibers maintained their geometry and orientation well, had an increased crystallinity, and showed a slightly damaged surface. Electron microscopy and thermal analysis showed that the interface between the PLA fiber and the PLA matrix had good compatibility, which was expected since they possess the same chemical structure. The modulus, tensile strength, and elongation, as well as the thermal stability of uniaxial poly(lactic acid) self-reinforced composites, were all significantly greater than those of the PDLLA film. The results showed that we have developed a method to prepare PLA composites with enhanced mechanical properties, without the problem of narrow processing temperature window normally required when using traditional thermal processing techniques. © 2015 Elsevier Ltd.


Gao C.,Center for Polymer from Renewable Resources | Gao C.,CSIRO | Gao C.,Monash University | Ma H.,Center for Polymer from Renewable Resources | And 7 more authors.
Polymer Engineering and Science | Year: 2013

The microstructure and thermal and mechanical properties of poly(lactic acid) (PLA) fibers after thermal treatment under both taut and free conditions at different temperatures were studied by differential scanning calorimetry, wide-angle X-ray diffraction, microscopy with polarized light, an acoustic method and tensile testing. In particular, the effects of thermal treatment conditions on crystallinity, molecular orientation, and mechanical properties, as well as their interrelationships, were investigated. Both the crystal orientation and crystallinity of the PLA fibers were higher after thermal treatment under taut conditions, even though the molecular orientation was not higher. Thermal treatment relaxed orientated segments, which resulted in increasing crystallinity; however, it did not indicate that the overall molecular alignment of the chains (molecular orientation) would necessarily be high. Tensile strength and elongation were increased with increasing treatment temperature up to 150°C, which corresponded to crystallinity and chain relaxation. The crystallinity detected by XRD, enthalpy measured by DSC, birefringence, and molecular orientation were compared to distinguish the effects of crystallinity, orientation of polymer chains, and crystals. Copyright © 2012 Society of Plastics Engineers.


PubMed | Yangzhou University, Center for Polymer from Renewable Resources, Monash University and CSIRO
Type: | Journal: Carbohydrate polymers | Year: 2016

Edible films from the blending hydroxypropyl methylcellulose (HPMC) with hydroxypropyl starch (HPS) have been developed. This work focuses on the relationship between morphologies and mechanical properties of such systems. To aid understanding of blend morphology, a new technique used to identify the two phases through dying of the HPS by iodine has been developed, which provided a simple and convenient way to clearly distinguish between HPMC and HPS phases. It was found that the blend system is immiscible and there is phase transition point depending on blending ratio and solution concentration. The lower transparency point of the blend and phase transition reign of HPMC from continuous phase to separated phase correspond with the variation of tensile modulus. The modulus and elongation decreased with increased solution concentration, which is correlatable with the morphologies present, where it was found that the HPMC gradually changed from a continuous phase to a distinct phase.


Wang Y.,Center for Polymer from Renewable Resources | Wang Y.,CSIRO | Zhang L.,Center for Polymer from Renewable Resources | Zhang L.,Monash UniversityClayton | And 8 more authors.
Carbohydrate Polymers | Year: 2016

Edible films from the blending hydroxypropyl methylcellulose (HPMC) with hydroxypropyl starch (HPS) have been developed. This work focuses on the relationship between morphologies and mechanical properties of such systems. To aid understanding of blend morphology, a new technique used to identify the two phases through dying of the HPS by iodine has been developed, which provided a simple and convenient way to clearly distinguish between HPMC and HPS phases. It was found that the blend system is immiscible and there is phase transition point depending on blending ratio and solution concentration. The lower transparency point of the blend and phase transition reign of HPMC from continuous phase to separated phase correspond with the variation of tensile modulus. The modulus and elongation decreased with increased solution concentration, which is correlatable with the morphologies present, where it was found that the HPMC gradually changed from a continuous phase to a distinct phase. © 2016 Elsevier Ltd

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