Nanocomposites of poly(propylene carbonate) reinforced with cellulose nanocrystals via sol‐gel process

Abstract

Cellulose nanocrystals (CNCs) organogels were first produced from aqueous dispersion through solvent exchange of CNCs to acetone via a simple sol-gel process. After mixing the organogels with poly(propylene carbonate) (PPC) in dimethylformamide followed by solution casting, green nanocomposites were obtained with CNCs well dispersed in PPC polymer matrix which was confirmed by scanning electron microscopy observations. Differential scanning calorimeter analysis revealed that glass transition temperature of the nanocomposites was slightly increased from 34.0 to 37.4 C. Tensile tests indicated that both yield strength and Young's modulus of CNCs/PPC nanocomposites were doubled by adding 10 wt % CNCs. However, poor thermal stability of PPC occurred after incorporating with CNCs due to the thermo-sensitive sulfate groups located on the surface of CNCs. Furthermore, PPC became more hydrophilic because of the inclusion of CNCs according to the water contact angle measurement. The enhanced mechanical and hydrophilic properties, coupled with the inherent superior biocompatibility and degradability, offered CNCs/PPC composites potential application in biomedical fields.

Green and Efficient Synthesis of Dispersible Cellulose Nanocrystals in Biobased Polyesters for Engineering Applications

“…Although melt processing by twin-screw extrusion is attractive for nancomposite manufacturing, dispersion of hydrophilic CNCs into hydrophobic matrices such as PLLA during melt processing remains challenging. Because of poor CNC dispersion, high CNC loadings in composites (e.g., from 5 to 10%-by-weight) are required ,,,, to improve significantly PLLA thermomechanical properties. The observed CNC aggregation in PLLA is a direct consequence of the fact that CNC surfaces are covered with hydrophilic hydroxyl groups .…”

Cellulose Nanocomposites

“…The research showed that the bond strength filler-PP depended on the chemical/ molecular interactions, composition and topographical nature of the fiber surface (44). Nanocomposites of PP carbonate reinforced with NCC as filler was produced via solgel process (45).…”

Poly(propylene carbonate) Nanocomposites Incorporating Non-functionalized Graphene Nanosheets Prepared by Microwave-assisted Exfoliation Process

“…Aliphatic poly(propylene carbonate) (PPC) synthesized from carbon dioxide and propylene oxide has drawn much attention in both research and industry owing to its eco-friendly nature leading to reduction of the amount of carbon dioxide as well as biodegradability. 1,2 Moreover, a completely amorphous PPC resin has potentially wide range of applications for packaging materials because of its excellent ductility, good melt flow characteristics, and high barrier property. 3 In spite of such advantages of biodegradable PPC resin, it still shows a limitation in the practical application of packaging films due to its inferior thermal and mechanical properties relative to traditional undegradable polymers.…”