scholarly journals Functional starch-based hydrogels: renewable material solutions for wastewater and agriculture industries

2020 ◽  
Author(s):  
◽  
Samira Siyamak
Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gerhild K. Wurzer ◽  
Hubert Hettegger ◽  
Robert H. Bischof ◽  
Karin Fackler ◽  
Antje Potthast ◽  
...  

Abstract Lignosulfonates (LSs) are by-products of the pulp and paper industry from pulping of lignocellulosic biomass according to the sulfite process. This renewable material already plays a role in low-value applications, such as binding agents for fuel, pellets, as a feed additive, or as a dispersant. Another possible field of application of this technical lignin type is agriculture. It is known that this eco-friendly and cheap material can improve soil quality, fertilizer efficacy and replace or decrease the use of potentially (eco)toxic organic or inorganic substances. The use of LS in agriculture and five main strategies for the implementation of LS in soil are discussed in this review: LS as a complexing agent with micronutrients, co-pelleting of LS with (macro)nutrients, capsule formation with LS for coating of fertilizers or pesticides, LS as a biostimulant, and ammonoxidation of LS. All five ways can be beneficial in fertilizer-related applications, either to slow down the release of nutrients or pesticides, to substitute harmful chemicals, or to inhibit nitrification and modify fertilizer behaviour. Nevertheless, application and long-time studies are often missing, and more research is required for generating products that are economically competitive to commercial bulk products.


Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2878
Author(s):  
Ehsan Bari ◽  
Asghar Sistani ◽  
Jeffrey J. Morrell ◽  
Antonio Pizzi ◽  
Mohammad Reza Akbari ◽  
...  

Rapid global population growth has led to an exponential increase in the use of disposable materials with a short life span that accumulate in landfills. The use of non-biodegradable materials causes severe damage to the environment worldwide. Polymers derived from agricultural residues, wood, or other fiber crops are fully biodegradable, creating the potential to be part of a sustainable circular economy. Ideally, natural fibers, such as the extremely strong fibers from hemp, can be combined with matrix materials such as the core or hurd from hemp or kenaf to produce a completely renewable biomaterial. However, these materials cannot always meet all of the performance attributes required, necessitating the creation of blends of petroleum-based and renewable material-based composites. This article reviews composites made from natural and biodegradable polymers, as well as the challenges encountered in their production and use.


2018 ◽  
Vol 51 (1) ◽  
pp. 26-35
Author(s):  
Steven C Peterson ◽  
Sanghoon Kim

Heat-treated starch (HTS) is a renewable material that can be used to modify the surface chemistry of small particles. In this work, HTS was used to coat hydrophilic biochar particles in order to make them more hydrophobic. Then, when added as filler to hydrophobic styrene–butadiene rubber (SBR), the coated biochar dispersed more easily and had enhanced filler–matrix interactions, which were reflected in the tensile properties of the final composites. Biochar particles modified with 5% (weight) HTS showed increases of 59% in the ultimate tensile strength, 49% in elongation percentage, and 79% in fracture toughness of SBR composites compared to unmodified biochar particles. This shows that HTS can be used to improve the tensile properties of composites filled with biochar and potentially other hydrophilic filler materials.


2021 ◽  
Vol 15 (3) ◽  
pp. 287-295
Author(s):  
Liucheng Wang ◽  
Huanhuan Zhao ◽  
Xianglin Song ◽  
Yake Li ◽  
Dong Li

Heavy metal pollution has adversely affected the ecological environment. As an eco-friendly and renewable material, biochar has a positive effect on environmental restoration. For study the feasibility of removing lead using corn straw biochar, the adsorption characteristics and mechanism were studied. This work prepared corn straw biochar at 300 °C, and its surface properties were characterized. The adsorption kinetics, isotherm, thermodynamics were determined. The result indicated the mechanism belonged ion exchange and complexation, and the experiment were controlled by comprehensive process, which included reaction rate and diffusion. The Langmuir model had better fitting results for the adsorption data, which indicated that adsorption was chemical adsorption and single molecular layer adsorption, and the maximum adsorption amount of corn straw biochar at 25 °C, 35 °C and 45 °C were 81.63 mg/g, 83.89 mg/g and 89.21 mg/g respectively. The thermodynamic analysis showed that increasing temperature was helpful to adsorption, and the adsorption was spontaneous. The results can be used for comprehensive utilization of straw and treatment of lead pollution.


Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2725 ◽  
Author(s):  
Jānis Andersons ◽  
Mikelis Kirpluks ◽  
Ugis Cabulis

Rigid low-density closed-cell polyurethane (PU) foams are widely used in both thermal insulation and structural applications. The sustainability of PU foam production can be increased by using bio-based components and fillers that ensure both enhanced mechanical properties and higher renewable material content. Such bio-based foams were produced using polyols derived from rapeseed oil and microcrystalline cellulose (MCC) fibers as filler. The effect of MCC fiber loading of up to 10 wt % on the morphology, tensile stiffness, and strength of foams has been evaluated. For estimation of the mechanical reinforcement efficiency of foams, a model allowing for the partial alignment of filler fibers in foam struts was developed and validated against test results. It is shown that although applying MCC fibers leads to modest gains in the mechanical properties of PU foams compared with cellulose nanocrystal reinforcement, it may provide a higher content of renewable material in the foams.


Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 140 ◽  
Author(s):  
Shidan Cummings ◽  
Yujie Zhang ◽  
Niels Smeets ◽  
Michael Cunningham ◽  
Marc Dubé

The substitution of petroleum-based synthetic polymers in latex formulations with sustainable and/or bio-based sources has increasingly been a focus of both academic and industrial research. Emulsion polymerization already provides a more sustainable way to produce polymers for coatings and adhesives, because it is a water-based process. It can be made even more attractive as a green alternative with the addition of starch, a renewable material that has proven to be extremely useful as a filler, stabilizer, property modifier and macromer. This work provides a critical review of attempts to modify and incorporate various types of starch in emulsion polymerizations. This review focusses on the method of initiation, grafting mechanisms, starch feeding strategies and the characterization methods. It provides a needed guide for those looking to modify starch in an emulsion polymerization to achieve a target grafting performance or to incorporate starch in latex formulations for the replacement of synthetic polymers.


2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Nik Alnur Auli Nik Yusuf ◽  
Mohammad Khairul Azhar Abdul Razab ◽  
Mohamad Bashree Abu Bakar ◽  
Khor Jia Yen ◽  
Chee Wing Tung ◽  
...  

This study summarizes the research on organic fillers, where eggshells were used as the reinforcement and banana peels as the matrix in the manufacturing of biocomposite thin film. Banana peel fibers exhibit a good characteristic of renewable material for the substitution of cement-based composites. However, biocomposite properties are limited by the poor adhesion between natural fiber interface and polymer matrix, which can be improved by chemical modification of fibers. In this research, banana peels were subjected to silane treatment. Biocomposite thin film manufacturing processes were carried out using blending and hand lay-up techniques with various concentrations of epoxy/waste banana peels/eggshell filler (EWE) ratios (EWE 0%, EWE 5%, and EWE 10%). X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and thickness swelling test were conducted on silane-treated and untreated banana peel biocomposite samples. In XRD analysis, it was found that EWE 10% sample had the highest crystallinity compared to EWE 0% and EWE 5%, and silane-treated samples had higher crystallinity than untreated samples.  For FTIR test, lignin component was removed in silane treatment based on the changes of IR peak characteristic where the new bonds (-Si-O-C-, -Si-O-Si-, and -Si-C-) were found in treated samples. Besides, TGA results showed that the thermal stability of silane-treated samples was improved significantly with the increase of eggshell filler percentage, which was proven by the decrease in the decomposition stage. In thickness swelling test, the samples achieved higher swelling percentage as the percentage of eggshell filler increased. However, the decrease of 5–6% in thickness swelling of treated samples was possibly offset by the enhancement in fiber/matrix interfacial adhesion. 


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