scholarly journals Solid-State Compounding for Recycling of Sawdust Waste into Green Packaging Composites

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1386
Author(s):  
Rula M. Allaf ◽  
Mohammad Futian

The present study explores solid-state cryomilling for the compounding of green composites. Herein, wood plastic composites (WPCs) composed of sawdust (SD) and poly(ε-caprolactone) (PCL) with various compositions were prepared. Two compounding techniques, namely, extrusion and cryomilling, were utilized to prepare WPC raw material pellets and powders, respectively, for comparison purposes. Flat pressing was further utilized to prepare WPC films for testing. Morphological, structural, thermal, mechanical, and surface wettability properties were investigated. Results indicate the advantages of cryomilling in producing WPCs. Scanning electron microscopy (SEM) along with optical micrographs revealed well ground SD particles and uniform distribution in the PCL matrix. Tensile strength and elongation at break of the composites declined with increasing SD content, however, the modulus of elasticity significantly increased. Water contact angles averaged less than 90°, implying partial wetting. Visual observations and thermo-gravimetric analysis (TGA) indicated thermal stability of composites during processing. In conclusion, PCL/SD WPC is a potential candidate to replace conventional plastics for packaging applications. This would also provide a much better utilization of the currently undervalued wood waste resources.

2012 ◽  
Vol 9 (2) ◽  
pp. 510-516 ◽  
Author(s):  
Esam A. Elhefian ◽  
Mohamed Mahmoud Nasef ◽  
Abdul Hamid Yahaya

Chitosan/agar (CS/AG) films were prepared by blending different proportions of chitosan and agar (considering chitosan as the major component) in solution forms. The thermal stability of the blended films was studied using thermal gravimetric analysis (TGA). It was revealed that chitosan and agar form a compatible blend. Studying the mechanical properties of the films showed a decrease in the tensile strength and elongation at break with increasing agar content. Blending of agar with chitosan at all proportions was found to form hydrogel films with enhanced swelling compared to the pure chitosan one. Static water contact angle measurements confirmed the increasing affinity of the blended films towards water suggesting that blending of agar with chitosan improves the wettability of the obtained films.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1728
Author(s):  
Peng Wen ◽  
Teng-Gen Hu ◽  
Yan Wen ◽  
Ke-Er Li ◽  
Wei-Peng Qiu ◽  
...  

An ethyl acetate extract from of Nervilia fordii (NFE) with considerable suppression activity on lipid peroxidation (LPO) was first obtained with total phenolic and flavonoid contents and anti-LPO activity (IC50) of 86.67 ± 2.5 mg GAE/g sample, 334.56 ± 4.7 mg RE/g extract and 0.307 mg/mL, respectively. In order to improve its stability and expand its application in antioxidant packaging, the nano-encapsulation of NFE within poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film was then successfully developed using electrospinning. SEM analysis revealed that the NFE-loaded fibers exhibited similar morphology to the neat PVA/PVP fibers with a bead-free and smooth morphology. The encapsulation efficiency of NFE was higher than 90% and the encapsulated NFE still retained its antioxidant capacity. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis confirmed the successful encapsulation of NFE into fibers and their compatibility, and the thermal stability of which was also improved due to the intermolecular interaction demonstrated by thermo gravimetric analysis (TGA). The ability to preserve the fish oil’s oxidation and extend its shelf-life was also demonstrated, suggesting the obtained PVA/PVP/NFE fiber mat has the potential as a promising antioxidant food packaging material.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1606
Author(s):  
Peng Yin ◽  
Jinglong Liu ◽  
Wen Zhou ◽  
Panxin Li

To improve the functional properties of starch-based films, chitin (CH) was prepared from shrimp shell powder and incorporated into corn starch (CS) matrix. Before blending, maleic anhydride (MA) was introduced as a cross-linker. Composite CS/MA-CH films were obtained by casting-evaporation approach. Mechanical property estimation showed that addition of 0–7 wt % MA-CH improved the tensile strength of starch films from 3.89 MPa to 9.32 MPa. Elongation at break of the films decreased with the addition of MA-CH, but the decrease was obviously reduced than previous studies. Morphology analysis revealed that MA-CH homogeneously dispersed in starch matrix and no cracks were found in the CS/MA-CH films. Incorporation of MA-CH decreased the water vapor permeability of starch films. The water uptake of the films was reduced when the dosage of MA-CH was below 5 wt %. Water contact angles of the starch films increased from 22° to 86° with 9 wt % MA-CH incorporation. Besides, the composite films showed better inhibition effect against Escherichia coli and Staphylococcus aureus than pure starch films.


2011 ◽  
Vol 415-417 ◽  
pp. 666-670 ◽  
Author(s):  
Na Lu ◽  
Shubhashini Oza ◽  
Ian Ferguson

Natural fiber reinforced composites are being used as reinforcement material in composite system due to their positive environmental benefits. Added to that, natural fibers offer advantages such as low density, low cost, good toughness, high specific strength, relatively non-abrasive and wide availability. However, the low thermal stability of natural fibers is one of the major challenges to increase their use as reinforcing component. In this study, a thorough investigation has been done to compare the effect of two chemical treatment methods on the thermal stability of hemp fibers. 5wt% sodium hydroxide and 5wt% triethoxyvinylsilane was used for the treatment of hemp fibers. Fourier transform infrared spectroscopy, scanning electron microscopy and thermo gravimetric analysis were used for characterization of untreated and treated fiber. The results indicated that 24 hours alkali treatment and 3 hours silane treatment time enhanced the thermal stability of the hemp fiber. However, alkali treatment shows better improvement compared to silane treatment.


2015 ◽  
Vol 05 (03) ◽  
pp. 1550018 ◽  
Author(s):  
P. Thomas ◽  
B. S. Dakshayini ◽  
H. S. Kushwaha ◽  
Rahul Vaish

Composites of poly(methyl methacrylate) (PMMA) and [Formula: see text] (STMO) were fabricated via melt mixing followed by hot pressing technique. These were characterized using X-ray diffraction (XRD), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), thermo mechanical analysis (TMA) and impedance analyser for their structural, thermal and dielectric properties. The coefficient of thermal expansion (CTE) was measured between 40°C and 100°C for pure PMMA is 115.2 ppm/°C, which was decreased to 78.58 ppm/°C when the STMO content was increased to 50 wt.% in PMMA. There was no difference in the glass transition ([Formula: see text]) temperature of the PMMA polymer and their composites. However, the FTIR analysis indicated possible interaction between the PMMA and STMO. The density and the hardness were increased as the STMO content increased in the PMMA matrix. Permittivity was found to be as high as 30.9 at 100 Hz for the PMMA+STMO-50 wt.% composites, indicating the possibility of using these materials for capacitor applications. The thermal stability of polymer was enhanced by incorporation of STMO fillers.


2014 ◽  
Vol 979 ◽  
pp. 315-318 ◽  
Author(s):  
W. Siriprom ◽  
K. Chantarasunthon ◽  
K. Teanchai

This work aims at characterizing the thermal and physical properties of chitosan. The samples were evaluated for potentiality to use as raw material for biodegradable films raw material. Their thermal and physical properties have been also discussed in detail which Fourier Transform Infrared Spectroscopy (FTIR), Thermo-Gravimetric Analysis (TGA), Energy Dispersive X-Ray Fluorescence (EDXRF) and X-Ray Diffraction (XRD), respectively. The result of the XRD pattern indicated the sample has amorphous-crystalline structure and FTIR results confirmed the formation of intermolecular hydrogen bonding between the amino and hydroxyl groups of the sample. In good agreement between the EDXRF and TGA results, noticed that the removal of moisture and volatile material.


2016 ◽  
Vol 857 ◽  
pp. 191-195 ◽  
Author(s):  
A. Nadiatul Husna ◽  
Bee Ying Lim ◽  
H. Salmah ◽  
Chun Hong Voon

Palm kernel shells (PKS) filled recycled high density polyethylene (rHDPE) biocomposites were produced using melt mixing. The biocomposites were prepared on Brabender Plasticorder at temperature of 185 °C and rotor speed of 50 rpm by varying filler loading (0 to 40 phr). In this study, the effect of PKS loading on rheological properties and thermal stability of rHDPE/PKS were investigated. Rheological study of the biocomposites was carried out by means of capillary rheometer under temperature of 190 °C, 200 °C and 210 °C. Thermal properties of biocomposites were studied by using thermo gravimetric analysis (TGA). The rheological results showed that the flowability of the composite increased with increasing temperature. Meanwhile, the result of TGA showed that at higher PKS loading, rHDPE/PKS biocomposites had lower total weight loss. The thermal stability of the biocomposites was reduced due to the addition of filler loading.


2011 ◽  
Vol 374-377 ◽  
pp. 1426-1429
Author(s):  
Xiao Meng Guo ◽  
Jian Qiang Li ◽  
Xian Sen Zeng ◽  
De Dao Hong

In this study, the thermal properties of a kind of new geotextile materials, so called controlled permeable formwork (CPF), were studied. Thermo-gravimetric analysis showed that the weight of CPF didn’t change much between 0~350 °C. Dynamic mechanical analysis showed that the storage modulus of CPF reduced from 25 MPa to around 10 MPa when the temperature rose to above 100 °C. The strength of sample decreased slightly with the increase of the temperature. The breaking elongation changed slightly with a maximum at 80 °C. The CPF showed excellent thermal stability and was suitable for general use in construction work.


2010 ◽  
Vol 6 (2) ◽  
pp. 1017-1023
Author(s):  
N.R.A. El-Mouhty ◽  
H. M. H. Gad ◽  
A. Y. El-Naggar

This study investigated the applicability of chemically (phosphoric acid) activated bagasse pith and date pits in the adsorption of water pollutants. The textural properties including porous parameters, monolayer equivalent surface area, total pore volumes, average pore radius, Methylene blue number and other physic-chemical characterization were investigated. The activated carbons were analyzed for moisture content, ash content. Ultimate analysis was done by using CHNS analyzer (Cairo University, Micro-analytical Center). To investigate the effect of phosphoric acid on the raw material, thermo gravimetric analysis (TGA) and differential thermo gravimetric (DTG) recordings were determined. The adsorption of heavy metals as pollutants, including Co, Sr, Cu, Cs, Pb, Cd, Ni, Fe, Zn, was studied in a batch experiments. Comparison of date pits activated carbon with commercial activated carbon was done, and the results indicated that using of prepared activated carbon for removal of Co, Sr, Cu, Cs, Pb, Cd, Ni,  Fe, Zn was  more effective than commercial activated carbon.


2018 ◽  
Vol 32 (6) ◽  
pp. 746-760 ◽  
Author(s):  
Guocheng Song ◽  
Yang Chen ◽  
Jing Zhu ◽  
Junrong Yu ◽  
Yan Wang ◽  
...  

Phenolphthalein polyethersulfone (PES-C)/silica (SiO2) composite nanofibrous membranes were prepared via solution blowing. The spinning solutions were prepared by mixing a solution of PES-C in dimethylacetamide with different amounts of colloidal SiO2 in ethylene glycol. Attenuated total reflectance–Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis, and water contact angles were conducted to characterize the properties of composite nanofibrous membranes. The results showed that the thermal properties and surface wettability were improved by the addition of appropriate amount of nano-SiO2. Furthermore, permeation fluxes of pure water and the filtration of starch suspension were measured to evaluate the antifouling property of the PES-C/SiO2 composite membranes.


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