Interfacial Properties and Melt Processability of Cellulose Acetate Propionate Composites by Melt Blending of Biofillers

Abstract

A series of eco-friendly biocomposites with improved mechanical properties and interfacial interaction were prepared by melt-mixing natural fibers using a cellulose acetate derivative as a polymer matrix and used to evaluate their mechanical, thermal, and morphological properties. The natural fiber used as a biofiller was pre-surface-treated by a refining process using alkali and natural enzymes to improve compatibility and increase interfacial bonding with biopolymer substrate. To increase the processability of the cellulose material, the raw material was plasticized and the composition prepared in the form of pellets in a twin-screw extruder by mixing with an additive before being molded through an injection process. For each composition, the interfacial bonding force between different materials was confirmed through morphology analysis and evaluation of mechanical and thermal properties. When biofillers and a viscosity modifier were used at the same time, the fabricated biocomposites had controllable crystallinity, stiffness, and elasticity and showed improved mechanical strength, such as tensile strength and flexural strength. These results indicated that interfacial properties could be increased through interfacial interactions between two different components due to appropriate surface treatment. In addition, it was confirmed that a composition having interfacial interaction, not a simple mixture, could be prepared by lowering both glass transition and melting temperature. The lowering of glass transition temperature increased the elasticity of the biocomposites, which have the potential advantage of easier melt processing when applied to various injection parts.

Controlled Allocation of Aromatic/Aliphatic Substituents to Polysaccharides and Lignin in Sugarcane Bagasse via Successive Homogeneous Transesterification Using Ionic Liquid

“…Although any clear correlation with the different Bz/He ratios was not observed for both T flow and T offset , the Bag-BzHe series was found to start melt-flowing at a much lower temperatures range of 122–143 °C than those for Bag-DeAc series and Bag-BzAc(71) (Figure S5). In precise, the thermal processability of thermoplastics can be evaluated from the gap between the decomposition temperature and melting/thermal-flowing temperature. , For instance, cellulose, featuring an intensive hydrogen-bonded structure, has a much higher melting temperature than its decomposition temperature, resulting in its significantlly poor thermal processability. Similarly, lignocellulosic biomass, including bagasse, cannot be melted and is not suitable for thermal molding.…”

“…In precise, the thermal processability of thermoplastics can be evaluated from the gap between the decomposition temperature and melting/thermal-flowing temperature. 30 , 31 For instance, cellulose, featuring an intensive hydrogen-bonded structure, has a much higher melting temperature than its decomposition temperature, resulting in its significantlly poor thermal processability. Similarly, lignocellulosic biomass, including bagasse, cannot be melted and is not suitable for thermal molding.…”

“…Then, several kinds of Bag-BzHe with different DS ratios of Bz/He groups were prepared by changing the amount of VBz added. The chemical structures of the Bag-BzHe series and Bag-HeBz as a reference were confirmed by ATR-mode FT-IR and 1 H qNMR (Figures S6 and S7), and the DS of the Bz/He groups and the residual OH content were determined using 31 P qNMR analysis after per-phosphitylation of the acylated bagasse (Figure S8). As summarized in Table 2, all the acylated bagasse contained less than 5% unreacted OH groups.…”

“…The content (mmol g −1 ) of each acyl group in the acylated bagasse was calculated from the integral ratio of the peak areas corresponding to the 1,4-BTMSB-d 4 and acyl group. Next, to quantify the unreacted OH content, quantitative 31 P NMR ( 31 P qNMR) was performed for the per-phosphitylated acylated bagasse using a predetermined concentration of internal standards in accordance with previous studies. 22−24 Finally, the DS of the acylated bagasse was calculated from the concentration ratio of the two acyl groups and unreacted OH groups.…”

Composite of Cellulose-Nanofiber-Reinforced Cellulose Acetate Butyrate: Improvement of Mechanical Strength by Cross-Linking of Hydroxyl Groups

“…In addition to the fibers, the use of a continuous polymer matrix phase is crucial because the matrix transfers stress between fibrils, reduces moisture sorption, allows composite shaping, and provides the opportunity for property tailoring [13]. Several thermoplastic cellulose derivatives, including cellulose acetate (CA), cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB), are widely used as bio matrices for composite materials [14,15]. In this case, it is possible to prepare the composite using a dry process by direct compounding (extrusion) of cellulose thermoplastic derivative and nanocellulosic filler [16].…”