Preparation and Properties of Green Composites Based on Tapioca Starch and Differently Recycled Paper Cellulose Fibers

Abstract

Green composites obtained from biodegradable renewable resources have gained much attention due to environmental problems resulting from conventionally synthetic plastics and a global increasing demand for alternatives to fossil resources. In this work we used different cellulose fibers from used office paper and newspaper as reinforcement for thermoplastic starch (TPS) in order to improve their poor mechanical, thermal and water resistance properties. These composites were prepared by using tapioca starch plasticized by glycerol (30 % wt/wt of glycerol to starch) as matrix reinforced by the extracted cellulose fibers with the contents ranging from 0 to 8 % (wt/wt of fibers to matrix). Properties of composites were determined by mechanical tensile tests, differential scanning calorimetry, thermogravimetric analysis, water absorption measurements, scanning electron microscopy, and soil burial tests. The results showed that the introduction of either office paper or newspaper cellulose fibers caused the improvement of tensile strength and elastic modulus, thermal stability, and water resistance for composites when compared to the non-reinforced TPS. Scanning electron microscopy showed a good adhesion between matrix and fibers. Moreover, the composites biological degraded completely after 8 weeks but required a longer time compared to the non-reinforced TPS. The results indicated that these green composites could be utilized as commodity plastics being strong, inexpensive, plentiful and recyclable.

Bionanocomposites reinforced with cellulose nanofibers derived from sugarcane bagasse

“…The peaks at 1,514 and 1,252 cm 21 in untreated bagasse represent the aromatic C 5 C stretch of aromatic rings of lignin. In cellulose nanofiber spectra, peak at 1,252 and 1,514 cm 21 is not present which indicate most of the lignin was removed and pure cellulose was isolated. The increase of the band at 898 cm 21 in CNF spectra obtained from chemically treated bagasse indicates the typical structure of cellulose and peak at 670 cm 21 is for C-O-H out-ofplane bending mode in cellulose.…”

“…The peaks at around 1,154 and 1,079 cm 21 were characteristic of C-O-H in starch, while the peak at 1,029 cm 21 was characteristic of the anhydroglucose ring O-C stretch [24]. The region below 800 cm 21 exhibited complex vibrational modes due to the skeletal mode vibrations of the pyranose ring in the glucose unit. It was observed that the relative peak strength of stretching vibrations for -OH groups in the FTIR spectra of composite films weakened with increase in % CNFs in the composite, indicating the hydrogen bonding between starch molecules was partially destroyed [4].…”

“…FTIR of cellulose nanofibers and nanocomposite film samples was done using Perkin Elmer RX infrared spectrophotometer. FTIR spectra were recorded in transmission mode in a spectral range of 4,000-400 cm 21 with a resolution of 2 cm 21 with a total of four scans for each sample. Scanning electron microscopy (SEM) of steam exploded bagasse fibers and nanocomposite films were done on scanning electron microscope model JSM JEOL-6100.…”

In situ development of self-defensive antibacterial biomaterials: phenol-g-keratin-EC based bio-composites with characteristics for biomedical applications

“…To determine the bio-degradability of the newly synthesised composites as reported method, 21 with some minute alternations was adopted, in this study. Briefly, test specimens about 30×30×1 mm in sizes were cut from each of the composite, dried and 105 equilibrated at room temperature in desiccators, and weighed to determine the reference weight (control).…”

Development of novel antibacterial active, HaCaT biocompatible and biodegradable CA-g-P(3HB)-EC biocomposites with caffeic acid as a functional entity

“…The biodegradability of the P(3HB)-EC and CA-g-P(3HB)-EC composites was evaluated using soil burial test as-described earlier by Wattanakornsiri et al [18]. The soil burial test lasted for 6 weeks (42 days).…”