scholarly journals Bio-Based Hydrogel and Aerogel Composites Prepared by Combining Cellulose Solutions and Waterborne Polyurethane

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 204
Author(s):  
Ling-Jie Huang ◽  
Wen-Jau Lee ◽  
Yi-Chun Chen
Keyword(s):  
Weight Loss ◽  
Raw Materials ◽  
Weight Ratio ◽  
Waterborne Polyurethane ◽  
Hydroxyethyl Cellulose ◽  
Composite Aerogel ◽  
Reduce Weight Loss ◽  
Cellulose Hydrogel ◽  
Application Potential ◽  
Water Swelling

Hydrogel composites can be prepared from cellulose-based materials and other gel materials, thus combining the advantages of both kinds of material. The aerogel, porous material formed after removing the water in the hydrogel, can maintain the network structure. Hydrogel and aerogel have high application potential. However, low mechanical strength and weight loss of cellulose hydrogel due to the water dehydration/absorption limit the feasibility of repeated use. In this study, cellulose hydrogels were prepared using microcrystalline cellulose (MC), carboxymethyl cellulose (CMC), and hydroxyethyl cellulose (HEC) as raw materials. Waterborne polyurethane (WPU) was added during the preparation process to form cellulose/WPU composite hydrogel and aerogel. The influence of the cellulose type and WPU addition ratio on the performance of hydrogel and aerogel were investigated. The results show that the introduction of WPU can help strengthen and stabilize the structure of cellulose hydrogel, reduce weight loss caused by water absorption and dehydration, and improve its reusability. The mixing of cellulose and WPU at a weight ratio of 90/10 is the best ratio to make the cellulose/WPU composite aerogel with the highest water swelling capacity and heat resistance.

scholarly journals End-of-Life Alternatives of Glass Reinforced Polyester Boat Hulls Compared by LCA

2018 ◽  
Vol 27 (4) ◽  
pp. 096369351802700 ◽  
Author(s):  
Mehmet Önal ◽  
Gökdeniz Neşer
Keyword(s):  
End Of Life ◽  
Environmental Impacts ◽  
Raw Materials ◽  
Weight Ratio ◽  
Cost Effective ◽  
Raw Material ◽  
Photochemical Oxidation ◽  
Human Toxicity ◽  
Vacuum Infusion ◽  
Infusion Method

Glass reinforced polyester (GRP), as a thermoset polymer composites, dominates boat building industry with its several advantages such as high strength/weight ratio, cohesiveness, good resistance to environment. However, proper recovering and recycling of GRP boats is became a current environmental requirement that should be met by the related industry. In this study, to propose in a cost effective and environmentally friendly way, Life Cycle Assessment (LCA) has been carried out for six scenarios include two moulding methods (namely Hand Lay-up Method, HLM and Vacuum Infusion Method, VIM) and three End-of-Life (EoL) alternatives(namely Extruding, Incineration and Landfill) for a recreational boat's GRP hulls. A case study from raw materials purchasing phase to disposal/recycling stages has been established taking 11 m length GRP boat hull as the functional unit. Analysis show that in the production phase, the impacts are mainly due to the use of energy (electricity), transport and raw material manufacture. Largest differences between the methods considered (HLM and VIM) can be observed in the factors of marine aquatic ecotoxicity and eutrophication while the closest ones are abiotic depletion, ozon layer depletion and photochemical oxidation. The environmental impact of VIM is much higher than HLM due to its higher energy consumption while vacuum infusion method has lower risk than hand lay-up method in terms of occupational health by using less raw material (resin) in a closed mold. In the comparison of the three EoL techniques, the mechanical way of recycling (granule extruding) shows better environmental impacts except terrestrial ecotoxicity, photochemical oxidation and acidification. Among the EoL alternatives, landfill has the highest environmental impacts except ‘global warming potential’ and ‘human toxicity’ which are the highest in extrusion. The main cause of the impacts of landfill is the transportation needs between the EoL boats and the licenced landfill site. Although it has the higher impact on human toxicity, incineration is the second cleaner alternative of EoL techniques considered in this study. In fact that the similar trend has been observed both in production and EoL phases of the boat. It is obvious that using much more renewable energy mix and greener transportation alternative can reduce the overall impact of the all phases considerably.

scholarly journals Manufacture of all-wood sawdust-based particle board using ionic liquid-facilitated fusion process

2021 ◽  
Vol 55 (2) ◽  
pp. 331-349
Author(s):  
Hannes Orelma ◽  
Atsushi Tanaka ◽  
Maija Vuoriluoto ◽  
Alexey Khakalo ◽  
Antti Korpela
Keyword(s):  
Tensile Strength ◽  
Ionic Liquid ◽  
Raw Materials ◽  
Weight Ratio ◽  
Fusion Process ◽  
The Novel ◽  
Particle Board ◽  
Microscopy Technique ◽  
Twin Screw ◽  
Fusion Approach

AbstractTraditional particle board can generate harmful indoor air emissions due to the volatile resin-based compounds present. This study investigated the preparation of sawdust particle board using the novel ionic liquid based fusion approach with [EMIM]OAc. The dissolution parameters were investigated using the thermal optical microscopy technique. The particle board sheets were prepared by hot pressing sawdust in the presence of ionic liquid (IL) ([EMIM]OAc) and subsequently purifying the fusion sawdust matrix from the IL with methanol. The fusion process of the sawdust particles was analysed with SEM and mechanical testing. The raw materials and the produced materials were investigated with elemental analysis, FTIR, and 13C-SS-NMR. IL fusion of the sawdust required a temperature above 150 °C, similar to the glass transition temperature (tg) of lignin. At lower temperatures, strong particle fusion was not obtained. It was observed that the sawdust/IL weight ratio was an important parameter of the fusion process, and a 1:3 weight ratio resulted in the strongest particle boards with a tensile strength of up to 10 MPa, similar to commercial particle boards. The particle fusion process was also studied with a twin-screw extruder. The extrusion enhanced the fusion of the sawdust particles by increasing dissolution of the sawdust particles, which was subsequently seen in elevated tensile strength (20 MPa). The study provides a practical view of how sawdust-based particle board can be manufactured using ionic liquid-based fusion.

Ciprofloxacin-loaded alginate/poly (vinyl alcohol)/gelatin electrospun nanofiber mats as antibacterial wound dressings

2021 ◽  
pp. 152808372199746
Author(s):  
Tittaya Thairin ◽  
Patcharaporn Wutticharoenmongkol
Keyword(s):  
Weight Loss ◽  
Vinyl Alcohol ◽  
Diffusion Method ◽  
Poly Vinyl Alcohol ◽  
Burst Release ◽  
Electrospun Nanofiber ◽  
Total Immersion ◽  
Water Swelling ◽  
Nanofiber Mats ◽  
And Diffusion

Herein, ciprofloxacin (CIP)-loaded alginate/poly (vinyl alcohol)/gelatin (SPG) (CIP–SPG) nanofiber mats were successfully fabricated by electrospinning. The average fiber diameters of the mats before and after crosslinking were in the range of 190–260 and 385–484 nm, respectively. The chemical integrity of CIP remained intact after encapsulation into the mats. The degree of weight loss and water swelling decreased with an increase in the gelatin content of the electrospun nanofiber mats. A release study was carried out by total immersion and diffusion methods using phosphate buffer as a release medium. Burst release of CIP was observed in case of the total immersion method, while a more sustained release was observed in case of the diffusion method. The maximum amounts of CIP released during total immersion and diffusion were in the range of 70–90% and 72–85%, respectively. For both the total immersion and diffusion methods, the released amounts of CIP decreased and the release slowed down with an increase in the gelatin content; this result is consistent with the weight loss and water swelling values. The Young’s modulus increased, while the tensile strength and strain at break decreased with an increase in the gelatin content. The CIP–SPG nanofiber mats were slightly toxic to L929 mouse fibroblasts as evaluated by indirect cytotoxicity assay. The electrospun CIP–SPG nanofiber mats exhibited excellent antimicrobial activity against Staphylococcus aureus and Escherichia coli. These results reveal that the electrospun CIP–SPG nanofiber mats are potentially promising materials for wound healing applications.

RATIONAL PROCESS PARAMETERS OF CHOPPED SEMI-FINISHED PRODUCTS PRODUCTION USING EMULSIONS FROM COLLAGENCONTAINING RAW MATERIALS

2020 ◽  
pp. 199-213
Author(s):  
I. Kaltovich
Keyword(s):  
Heat Treatment ◽  
Weight Loss ◽  
Connective Tissue ◽  
Raw Materials ◽  
Steam Treatment ◽  
Point System ◽  
Technological Parameters ◽  
Genus Lactobacillus ◽  
Rational Process

The article presents the results of research on the determination of rational technological parameters for the production of chopped semi-products using emulsions from collagen-containing raw materials fermented by bacteria of the genus Lactobacillus. Water dosages are installed in the composition of chopped semi-finished products: 12% – with emulsions from pork skin and tails and 11% - with emulsion from connective tissue. Duration of ingredients mixing (5 minutes), sequence of raw materials laying during manufacture of articles, as well as duration of heat treatment of chopped semiproducts is determined: 25 minutes – during steaming (t = 95–100 °С), 20 minutes – during baking (t = 180 °C), 15 minutes – during frying (t = 110 °C), while recommended methods of bringing semifinished products to culinary readiness are steam treatment and baking, which allow for improved functional and technological (TUS – 79.3-81.8%, weight loss during heat treatment – 5.1–7.9%), structural and mechanical (PNS - 1413.9–1470.4 Pa) and organoleptic indicators (juiciness, appearance, consistency, taste, smell) of these products (9 points according to the 9-point system).

Identification of Forming Limits for Unidirectional Carbon Textiles in Reality and Mesoscopic Simulation

2013 ◽  
Vol 554-557 ◽  
pp. 423-432 ◽  
Author(s):  
Patrick Böhler ◽  
Frank Härtel ◽  
Peter Middendorf
Keyword(s):  
Raw Materials ◽  
Weight Ratio ◽  
Experimental Tests ◽  
Simulation Method ◽  
Failure Criteria ◽  
Forming Process ◽  
Mesoscopic Simulation ◽  
Sewing Thread ◽  
Young’S Moduli ◽  
Definition Of

In several fields of engineering the use of carbon fibre reinforced material (CFRP) is increasing. Minimized weight due to CFRPs could lead to lower consumption of raw materials especially in the automotive area. The goal within the research project TC² is the decrease of costs and production time for composite materials. To achieve better performance to weight ratio and to get acceptable production conditions the draping of dry unidirectional textiles and a following RTM process is investigated. Due to the high degree of complexity of automotive structures the forming process is challenging. Gapping in the textile could appear at corners as well as wrinkling or flexion of the fibres. To be able to define the amount and direction of layers or patches it is necessary to know the limits of forming for unidirectional material and to be able to predict the behaviour of the textile during the forming process. For the definition of the process limits several draping strategies are performed on different corner blend geometries. The goal of that work is to define the critical gradient of the flange to get first failures such as wrinkling or gapping. It is also important to understand the influence of different draping strategies. Parallel to the experimental tests a mesoscopic simulation method using an approach with roving and sewing thread is developed and presented. It is able to predict the material behaviour in critical areas (gapping, wrinkling). Different Young’s moduli and failure criteria can be implemented for the two main directions as well as for the bending of the textile. A validation with the experimental results is performed with the aim to enable the prediction of the textile behaviour using simulation methods.

Softened food reduces weight loss in the streptozotocin-induced male mouse model of diabetic nephropathy

2018 ◽  
Vol 52 (4) ◽  
pp. 373-383 ◽  
Author(s):  
Sisse A Nørgaard ◽  
Fredrik W Sand ◽  
Dorte B Sørensen ◽  
Klas SP Abelson ◽  
Henrik Søndergaard
Keyword(s):  
Weight Loss ◽  
Diabetic Nephropathy ◽  
Mouse Model ◽  
Diabetic Mouse ◽  
Diabetic Mice ◽  
Reduce Weight Loss ◽  
Normal Chow ◽  
Corticosterone Metabolites ◽  
Reducing Stress ◽  
Humane Endpoint

The streptozotocin (STZ)-induced diabetic mouse is a widely used model of diabetes and diabetic nephropathy (DN). However, it is a well-known issue that this model is challenged by high weight loss, which despite supportive measures often results in high euthanization rates. To overcome these issues, we hypothesized that supplementing STZ-induced diabetic mice with water-softened chow in addition to normal chow would reduce weight loss, lower the need for supportive treatment, and reduce the number of mice reaching the humane endpoint of 20% weight loss. In a 15 week STZ-induced DN study we demonstrated that diabetic male mice receiving softened chow had reduced acute weight loss following STZ treatment ( p = 0.045) and additionally fewer mice were euthanized due to weight loss. By supplementing the diabetic mice with softened chow, no mice reached 20% weight loss whereas 37.5% of the mice without this supplement reached this humane endpoint ( p = 0.0027). Excretion of corticosterone metabolites in faeces was reduced in diabetic mice on softened chow ( p = 0.0007), suggesting lower levels of general stress. Finally, it was demonstrated that the water-softened chow supplement did not significantly affect the induction of key disease parameters, i.e. %HbA1C and albuminuria nor result in abnormal teeth wear. In conclusion, supplementation of softened food is refining the STZ-induced diabetic mouse model significantly by reducing stress, weight loss and the number of animals sacrificed due to humane endpoints, while maintaining the key phenotypes of diabetes and nephropathy.

A review on the mechanical properties of textile structural composite T-beams

2019 ◽  
Vol 90 (5-6) ◽  
pp. 710-727 ◽  
Author(s):  
Yiwei Ouyang ◽  
Xianyan Wu
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Raw Materials ◽  
Research Progress ◽  
Future Research ◽  
Research Directions ◽  
Structural Composite ◽  
Delamination Resistance ◽  
Application Potential ◽  
Future Research Directions

In order to review the most effective ways to improve the mechanical properties of composite T-beams and further increase their application potential, research progress on the mechanical properties of textile structural composite T-beams was summarized based on two-dimensional (2-D) ply structure composite T-beams, delamination resistance enhanced 2-D ply structure T-beams, and three-dimensional (3-D) textile structural composite T-beams; future research directions for composite T-beams were also considered. From existing literature, the research status and application bottlenecks of 2-D ply structure composite T-beams and T-beams with enhanced delamination resistance performance were described, as were the specific classification, research progress, and mechanical properties of 3-D textile structural composite T-beams. In addition, the superior mechanical properties of 3-D braided textile structural composite T-beams, specifically their application potential based on excellent delamination resistance capacity, were highlighted. Future research directions for composite T-beams, that is, the applications of high-performance raw materials, locally enhanced design, structural blending enhancement, functionality, and intelligence are presented in this review.

Swelling of PVA/Chitosan/TiO2 Nanofibers Membrane in Different PH

2020 ◽  
Vol 990 ◽  
pp. 220-224
Author(s):  
Ari Dwi Nugraheni ◽  
Diki Purnawati ◽  
Ani Rohmatillah ◽  
Dian Nur Mahardika ◽  
Ahmad Kusumaatmaja
Keyword(s):  
Time Constant ◽  
Weight Ratio ◽  
Low Ph ◽  
Membrane Stability ◽  
Swelling Behavior ◽  
Cross Linking ◽  
High Ph ◽  
Chitosan Concentration ◽  
Nanofiber Membranes ◽  
Water Swelling

The nanofiber PVA/chitosan have been successfully fabricated by the addition of TiO2 or without TiO2. Nanofiber membranes of PVA/chitosan/TiO2 were fabricated with weight ratio of PVA/chitosan (w/w) 90/10, 85/15, and 80/20. Glutaraldehyde cross-linking was added to increase membrane stability in water. Swelling behavior was tested in three different pH to investigate the swelling behavior of nanofiber membranes of PVA/chitosan with and without TiO2. The result indicated that the addition of chitosan concentration would decrease the swelling index, and increase the time constant (τ). The swelling index will increase in high pH (pH 10.01) compare to low pH (pH 4.01).

Microbial Oil Production from Lignocellulosic Biomass – Recent Development and Prospect

2014 ◽  
Vol 541-542 ◽  
pp. 397-403
Author(s):  
Zhang Nan Lin ◽  
Hong Juan Liu ◽  
Zhi Qin Wang ◽  
Jia Nan Zhang
Keyword(s):  
Lignocellulosic Biomass ◽  
Large Scale ◽  
Raw Materials ◽  
Oil Production ◽  
Renewable Resource ◽  
Raw Material ◽  
Biodiesel Production ◽  
Microbial Oil ◽  
Key Issues ◽  
Application Potential

Microbial oil is one of the ideal raw materials for biodiesel production because of its rapid reproduction and less influence by the climate and season variation. However, the high cost is one of the key issues that restricted its production in a large-scale. Lignocellulosic biomass, the cheap and renewable resource, might be the best raw material for microbial oil production by oleaginous microorganisms. Recent development on the microbial oil production from lignocellulosic biomass was summarized in this paper. Furthermore, the challenges and application potential of microbial oil were prospected.

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