Swelling behavior of butyl and chloroprene rubber composites with poly(sodium acrylate) showing high water uptake

2019 ◽  
Vol 137 (14) ◽  
pp. 48535 ◽  
Author(s):  
Yuya Oyama ◽  
Yusuke Hiejima ◽  
Koh‐hei Nitta
Keyword(s):  
Water Uptake ◽  
High Water ◽  
Swelling Behavior ◽  
Sodium Acrylate ◽  
Rubber Composites ◽  
Chloroprene Rubber

Hydraulic segmentation does not protect stems from acute water loss during fire

2021 ◽  
Author(s):  
William A Hoffmann ◽  
Amanda C Rodrigues ◽  
Nicholas Uncles ◽  
Lorenzo Rossi
Keyword(s):  
Water Uptake ◽  
Water Loss ◽  
High Water ◽  
Fire Plume ◽  
Magnolia Grandiflora ◽  
Hydraulic Failure ◽  
Factors Influencing ◽  
Wide Range ◽  
Transport Path ◽  
Measured Water

Abstract The heat plume associated with fire has been hypothesized to cause sufficient water loss from trees to induce embolism and hydraulic failure. However, it is unclear whether the water transport path remains sufficiently intact during scorching or burning of foliage to sustain high water loss. We measured water uptake by branches of Magnolia grandiflora while exposing them to a range of fire intensities, and examined factors influencing continued water uptake after fire. Burning caused a 22-fold mean increase in water uptake, with greatest rates of water loss observed at burn intensities that caused complete consumption of leaves. Such rapid uptake is possible only with steep gradients in water potential, which would likely result in substantial cavitation of xylem and loss of conductivity in intact stems. Water uptake continued after burning was complete, and was greatest following burn intensities that killed leaves but did not consume them. This post-fire uptake was mostly driven by rehydration of the remaining tissues, rather than evaporation from the tissues. Our results indicate that the fire-plume hypothesis can be expanded to include a wide range of burning conditions experienced by plants. High rates of water loss are sustained during burning, even when leaves are killed or completely consumed.

Preparation and properties of water-absorbent composites of chloroprene rubber, starch, and sodium acrylate

2010 ◽  
Vol 22 (12) ◽  
pp. 1778-1785 ◽  
Author(s):  
Shuai-Shuai Song ◽  
Hong-Bin Qi ◽  
You-Ping Wu
Keyword(s):  
Sodium Acrylate ◽  
Chloroprene Rubber

Processing polymer nanocomposites with natural additives for medical applications

2019 ◽  
Vol 39 (2) ◽  
pp. 178-185
Author(s):  
Demet Topaloğlu Yazıcı ◽  
Arzu Yener
Keyword(s):  
Olive Oil ◽  
Polymer Nanocomposites ◽  
Water Uptake ◽  
High Water ◽  
Medical Applications ◽  
Drug Adsorption ◽  
Hydrophobizing Agent ◽  
Images Processing ◽  
Natural Additive ◽  
Natural Additives

Abstract The aim of this study is to analyze the effect of natural additive incorporation on processing nanocomposites and their effect on the functional characteristics of nanocomposites such as water uptake characteristics, drug adsorption and dissolution behaviors. Chitosan and montmorillonite were processed with olive oil and glycerin natural additives. In order to compare the processing results, the structure and the morphology of the polymer nanocomposites were examined by using infrared spectra, X-ray diffractograms and electron microscope images. Processing with nontoxic and healthful olive oil as a hydrophobizing agent overcame the high water uptake properties of the polymer nanocomposites and eliminated the use of other expensive chemicals. The nanocomposites without additives adsorbed the highest amounts of methylene blue at equilibrium. In vitamin B12 dissolution studies, not only the additives but also the reinforcement affected the results. Obviously, it can be seen that both the natural additive types and the reinforcement modification effects governed the drug adsorption and dissolution behaviors of the new tailored polymer nanocomposites. Moreover, the additives also improved the processing and handling abilities of these polymer nanocomposites. According to the results, these nanocomposites are promising candidates for medical applications like as a carrier for drug delivery and for skin treatment studies.

scholarly journals New Semi-IPN Hydrogels Based on Cellulose for Biomedical Application

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
S. K. Bajpai ◽  
M. P. Swarnkar
Keyword(s):  
Free Radical ◽  
Kinetic Model ◽  
Water Uptake ◽  
Diffusion Coefficients ◽  
Biomedical Application ◽  
Paper Industry ◽  
Swelling Behavior ◽  
Late Time ◽  
Cellulose Pulp ◽  
Uptake Data

Cellulose pulp, obtained from a paper industry, has been dissolved in PEG/NaOH system and the resulting solution has been polymerized in the presence of monomer acrylic acid (AA) and crosslinker N,N′ methylene bisacrylamide via free radical polymerization. The Cell/PEG/poly (SA) ternary semi-IPN hydrogel, so prepared, was characterized by FTIR and TG analysis. The dynamic water uptake of various hydrogels, having different compositions, was investigated in the physiological buffer of pH 7.4 at 37°C. The various hydrogels exhibited chain-relaxation controlled swelling behavior. The uptake data was best interpreted by Schott kinetic model. The various diffusion coefficients, that is, initial (Di), average (Dave), and late time (DL), were also calculated using the dynamic water uptake data. The hydrogels showed fair pH and salt-dependent swelling behavior.

Influence of Citric Acid and Curing Time on Water Uptake

2014 ◽  
Vol 625 ◽  
pp. 123-126 ◽  
Author(s):  
Sohibatul Muizzah Mohamad Izhar ◽  
Ku Zilati Ku Shaari ◽  
Zakaria Man ◽  
Yon Norasyikin Samsudin
Keyword(s):  
Citric Acid ◽  
Water Uptake ◽  
Barrier Properties ◽  
High Water ◽  
Cross Linking ◽  
Curing Time ◽  
Gas Barrier ◽  
Water Sensitivity ◽  
Hydrophilic Character ◽  
Starch Films

Starch is highly promising biopolymer for the production of packaging material since it gives films a good tensile and gas barrier properties. However, non-plasticized starch films are brittle and their hydrophilic character results in poor moisture barrier properties and high water sensitivity. In order to improve films formation and material properties of starch, plasticization and chemical modification such as cross-linking of the starch is required. The cross-linking reaction able to improve thermal stability, tensile strength and decreased the dissolution of starch films in water and formic acid. From the study, the percentage of water uptake reduced when the blending ratio of citric acid increased.The percentage of water uptake highly affected by curing time compared to blending ratio. Increasing the curing time from 1 hour to 2 hour significantly reduced the percentage of water uptake. At 4 hour curing time, the percentage water uptake reached equilibrium faster than 3 hour curing time. This shows that more citric acid molecules were chemically bonded with the starch chains, resulting in higher cross link degree and thus, reduced the percentage of water uptake.

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