Amount Of Absorbed Water Research Articles

Nonisocyanate Biobased Poly(ester urethanes) with Tunable Properties Synthesized via an Environment-Friendly Route

The objective of this study was to explore an environment-friendly route to synthesize nonisocyanate based poly(ester urethanes) of poly(1,10-bis(hydroxyethyloxycarbonylamino) decane-co-dicarboxylic acid) (PBDA) from renewable materials/resources. In specific, 1,10-bis(hydroxyethyloxycarbonylamino)decane (BHD) was first synthesized from ethylene carbonate and decamethylene diamine via the melt ring-opening reaction. Subsequently, the PBDAs with tunable properties were synthesized from BHD and five dicarboxylic acids (including three biobased ones of oxalic acid, sebacic acid, and itaconic acid) via the melt polycondensation reaction. The structural, physical, and mechanical properties of PBDAs were characterized by FTIR, NMR, XRD, GPC, TGA, and mechanical testing machine; additionally, the environmental stability was evaluated upon measuring the water absorption amount in deionized water and the degradation percentage in phosphate buffer saline. The results indicated that the PBDAs possessed reasonably good properties and thus could potentially be used for engineering applications; moreover, because their macromolecular chains/backbones contained ester and urethane groups (which would usually result in excellent cytocompatibility), it was envisioned that these PBDAs might also be suitable for some biological and/or biomedical applications.

Evaluation of Quality Characteristics of Potato Slices during Drying by Infrared Radiation Heating Method under Vacuum

The effect of drying behaviour on the drying rate and quality characteristics of potato slices in a vacuum- infrared drying system was studied. In this work, the effect of the infrared radiation powers (100, 150, and 200 W) and vacuum levels (20, 80, 140 mmHg and atmosphere pressure) at different slice thickness (1, 2 and 3 mm) on drying rate and shrinkage percentage and rehydration capacity were investigated. From the study, it was concluded that IR power level has a significant effect on processing time and drying rate. With increasing radiation power, time drying is reduced and consequently drying rate is increased. The drying rate curve of potato slices at initial drying time is in the ascending phase because of surface moisture evaporation and after this phase due to the start of influence of water from within of material to surface descending phase occurs. Also, shrinkage percentage increased with increase of sample thickness. In other words, shrinkage was decreased at different thickness with an increase of infrared radiation power and vacuum level. It was discovered that the long period of drying and increase of sample thickness may have contributed to a decrease in rehydration capacity. Because of porous texture of potato, as soon put in boiling water for 3 minutes, the water absorption process quickly started and before the insert damage to product tissues, to maximum amount of water absorption will reach. The results also showed that with increasing shrinkage, rehydration capacity was decreased.

Ion-Pair Conductivity Theory: Mixtures of Butanol with Various Non-Polar Liquids and Water

In our previous paper [A. Dukhin and S. Parlia, J. Electrochem. Soc., 162, H1 (2015)] we suggested a theory that fits experimental data for mixtures of various alcohols with toluene within the full composition range. This theory is based on the general expression for ionic strength given by Aurbach [D. Aurbach and M. Dekker, Nonaqueous Electrochemistry (1999)]. In this paper we test if the chemical nature of non-polar liquids affects conductivity of such mixtures by mixing butanol with different non-polar liquids. We discovered no effect of the non-polar liquid chemistry on mixture conductivity. This agrees with our assumption that, with regards to the non-polar media, only dielectric constant matters for ionization of these mixtures. As a next step we studied the role of contamination with water on ionization of these mixtures. Our tests suggest that even small amounts of water absorption from air contribute significantly to the conductivity of alcohol, and consequently, to the conductivity of the mixtures. This does not prevent conducting reproducible measurements because equilibrium is established quickly and solvation of various ions by alcohol molecules averages overall ion geometry. Determination of the water contribution to the conductivity allows us to estimate the dissociation constant of butanol.

Building wooden panels glued with a combination of natural adhesive of tannin/Eremurus root (syrysh)

The possibility of combination of tannin adhesive with natural and renewable adhesive of syrysh (Eremurus root) was investigated. The combination of Mimosa tannin adhesive with syrysh adhesive was considered in six levels. Pressing temperature was 210 °C, pressure was 35 kg/cm2, and pressing time was 7 and 10 min. The highest level of adhesive resistance was obtained for 6 % tannin + 4 % syrysh, 0.89 MPa. By increasing the percentage of the dry weight of the syrysh adhesive, the amount of water absorption and thickness swelling were decreased and reached standard level.

Thermal and Flexural Properties and Water Absorption of Caulis Spatholobi Residue Fiber Reinforced Biodegradable Poly(propylene carbonate) Composites

Abstract This paper investigated and compared the thermal and flexural properties and water absorption of natural caulis spatholobi residue fibers reinforced PPC/CSRF composites. Polypropylene carbonate (PPC) was reinforced by caulis spatholobi residue fibers (CSRF) which had been pretreated by continuous steam explosion. The effect of fiber content (10 to 60 wt%) on the properties and water absorption of PPC/CSRF biodegradable composites was investigated. The thermal properties of PPC/CSRF composites indicated that the addition of CSRF could improve the thermal stability of the composites. The flexural strength and modulus of the composites were found to be improved as the content of fiber increased. From the SEM micrographs, it was found that a small amount of fibers were pulled out on fractured surfaces of the composites, showing good network structure between the fiber and PPC matrix. The water absorption amount of the composites increased with increasing the fiber content. This paper demonstrates that the incorporation of low-cost and biodegradable caulis spatholobi residue fiber into PPC provides a practical way to produce completely biodegradable and cost-competitive composites with good mechanical properties.

ИЗМЕНЕНИЕ ПРОЧНОСТНЫХ И УПРУГИХ СВОЙСТВ ПО-ЛИМЕРНОГО КОМПОЗИЦИОННОГО МАТЕРИАЛА ПРИ ВВЕДЕНИИ В СОСТАВ ГРАФИТА

It is known that a decrease in strength composite material associated with the amount of water absorption. Some components of wood-fiber-glass compo-site material (graphite flour) is introduced with the purpose to reduce the effects of water absorption, as well as the washing of water-soluble components.

Characterizing the transplanar and in-plane water transport of textiles with gravimetric and image analysis technique: Spontaneous Uptake Water Transport Tester.

Water absorption and transport property of textiles is important since it affects wear comfort, efficiency of treatment and functionality of product. This paper introduces an accurate and reliable measurement tester, which is based on gravimetric and image analysis technique, for characterising the transplanar and in-plane wicking property of fabrics. The uniqueness of this instrument is that it is able to directly measure the water absorption amount in real-time, monitor the direction of water transport and estimate the amount of water left on skin when sweating. Throughout the experiment, water supply is continuous which simulates profuse sweating. Testing automation could even minimise variation caused by subjective manipulation, thus enhancing testing accuracy. This instrument is versatile in terms of the fabrics could be tested. A series of shirting fabrics made by different fabric structure and yarn were investigated and the results show that the proposed method has high sensitivity in differentiating fabrics with varying geometrical differences. Fabrics with known hydrophobicity were additionally tested to examine the sensitivity of the instrument. This instrument also demonstrates the flexibility to test on high performance moisture management fabrics and these fabrics were found to have excellent transplanar and in-plane wicking properties.

Effect of Purification on Nano Microbial Cellulose Pellicle Properties

Nano Microbial Cellulose (NMC) is one of the most effective biopolymer in treating the injury. It has many applications in medical field due to unique properties such as high water absorption, compatibility with body and transparency for medical examination.Accordingly, this research attempts to evaluate the characteristic of raw and purified microbial cellulose for medical usage. The chemical and physical structure of microbial cellulose layer was assessed by FTIR and XRD. In addition, water absorption, wettability and permeability of raw and purified microbial cellulose pellicle were investigated and SEM was applied for assessing the surface of nanocellulose pellicle.FTIR result confirmed the cellulosic structure of pellicle and XRD represented that the crystallinity of NMC was more than cotton (plant cellulose). The obtained result indicated that the amount of water absorption of purified layer is 10% less than raw layer but wettability of the treated layer is increased more than 50%. No permeability was representing against air pressure in raw and purified samples in wet and dry forms at 25Pa. Therefore, applying purification treatment improved the NMC pellicle properties for modern wound dressing.

Mechanical Properties and Water Absorption Behaviour of Durian Rind Cellulose Reinforced Poly(lactic acid) Biocomposites

<span lang='EN-AU'>Environmental concerns have resulted in replacing petrochemically derived polymer with biodegradable renewable resource. In this study, mechanical properties and water absorption behaviour of durian rind cellulose reinforced poly(lactic acid) biocomposites were investigated. Poly(lactic acid) was mixed with 25 and 35 wt. % of durian rind cellulose that was derived from durian consumption wastes. The biocomposties were melt-blended at 165 and 175 °C with 15 min using a Brabender internal mixer followed by a hot compression moulding technique. The results showed that impact strength and modulus of Young increased with increasing of cellulose content but decreased at higher mixing temperature. Water absorption behaviour of biocomposites as function of days was also investigated. It was found that the water absorption amount of biocomposites increased with increasing of cellulose content and exposure time. </span>

Hygrothermal aging effects on fatigue of glass fiber/polydicyclopentadiene composites

We investigated the effects of hygrothermal aging on the tension–tension fatigue behavior of unidirectional (UD) glass/polydicyclopentadiene (pDCPD) composites. Samples were immersed in deionized (DI) water and salt water, and glass/epoxy composites were used as a benchmark for comparison. Composites of pDCPD showed less water uptake and superior fatigue performance compared to similarly aged epoxy composites, a distinction attributed to the intrinsic hydrophobicity of the pDCPD resin. Superior fiber-matrix interface adhesion in pDCPD composites accounted for the greater strength retention after aging. Degradation of fiber and interface were coupled but not synchronous: glass fiber degradation was determined by aging time, while interface degradation depended primarily on moisture level. Salt water influenced the amount of water absorption, but no salt water corrosion was observed for either composite.

Formation and properties of core–shell pentablock copolymer/silica hybrids

Two novel core–shell pentablock copolymer/silica hybrids are prepared for coating applications via growing silica on the precursor of pentablock copolymer PDMS-b-(PMMA-b-PMPS)2 (PDMM), which is synthesized by dimethylsiloxane (DMS), methylmethacrylate (MMA) and 3-(trimethyoxysilyl)propyl methacrylate (MPS). The hybrid of PDMM core/silica shell (PDMM@SiO2) is obtained by the assembled PDMM in THF/CH3OH solution with tetraethyl orthosilicate (TEOS), but the hybrid of silica core/PDMM shell (SiO2@PDMM) is obtained by the hydrolyzed TEOS with –Si(OCH3)3 groups during assembling of PDMM in THF solution. PDMM@SiO2 could produce a film distributed agminated SiO2 particles with 45 nm roughness, but SiO2@PDMM could produce a film scatted individual SiO2 particles with 26 nm roughness. Therefore, PDMM@SiO2 film gives an obvious hydrophobicity (116°), higher Tg (121 °C), high Td (>400 °C), low amount of water absorption (300 Hz of Δf), low viscoelasticity (−0.32 of ΔD/Δf), but tight layer structure (10 × 10−6 of ΔD) and high storage modulus (2350 MPa). However, both core–shell hybrids have the similar adhesion to the substrate (185–187 N).

引っかき傷によるコンクリートブロック構工法の目地強度管理方法の検討

This paper deals with the estimation method of joint mortar strength in CB masonry with scratch for the quality control. According to the test results, it was found the correlation between strength and width of scratch. The test results also showed that the surface roughness and the moisture content in joint affected the width of scratch. The width was increased with increase of the moisture content and the surface roughness. Water absorption amount of CB from mortar depended on the mortar type, CB type and joint width and it was found that mortar strength was reduced by water absorption of CB. Finally, we proposed an estimation method for joint mortar strength using the scratch test and quality control method on the basis of these results.

Experimental characterization and simulation of water vapor diffusion through various encapsulants used in PV modules

Water vapor ingress significantly impacts the performance and the long-term reliability of copper indium gallium selenide photovoltaic modules. A cost effective packaging method that can protect photovoltaic modules from the operating environment is critical to their widespread commercialization. Due to the sensitivity of both the copper indium gallium selenide cells and the electrodes to water vapor, they need an encapsulant with low water vapor permeation as well as side sealing materials, resulting in a high cost of manufacturing. Hence, a packaging strategy without sealing materials is proposed with new encapsulant materials. In this study, the overall amount of permeated water vapor through ionomer and polyvinyl butyral encapsulants was investigated and compared with widely used encapsulants such as ethylene vinyl acetate. The diffusion and solubility coefficients were calculated from the experimentally determined water vapor transmission rate in both transient and steady state transport regimes. To understand the permeation mechanism of water vapor through the encapsulant, the temperature dependence of the diffusion and solubility coefficients was investigated. Based on experimentally determined permeation properties, the amount of water vapor absorption and the ingress speed into the PV module under a continuously varying environment were investigated. Ethylene vinyl acetate shows its excellence among encapsulants, when simply considering ingress speed of water vapor (slower permeation), while ionomer dominantly outperforms other materials, when focusing on the total amount of water absorption (less permeation).

Mechanical activation of chemically activated high phosphorous slag content cement

Abstract Increase of specific surface area by mechanical activation accelerates hydration reactions of cements and results in higher compressive strengths. The compressive strength development of chemically activated high phosphorous slag content cement at different Blaine finenesses has been investigated. Mixes of phosphorous slag (80 wt.%), Portland cement (14 wt.%), and compound chemical activator (6 wt.%) were prepared at different Blaine finenesses using a laboratory ball mill. Compressive strengths of mortar specimens cured in lime-saturated water were measured at different curing times. Results show that increasing fineness to 450 m2/kg, provides the possibility of achieving high 28-day compressive strengths up to almost 93 MPa. Complementary measurements confirmed that increasing fineness results in significant reductions in the amount of water absorption and the total open pore volume of mortar specimens. The simultaneous application of both chemical and mechanical activations, therefore, provides complementary improving effects in the quality of high phosphorous slag content cements.

수분 흡수가 단열재의 열전도계수에 미치는 영향에 관한 연구

IInsulation material is generally used for preventing heat loss from heat transport fluids, and water absorption severely reduces the insulation property. The purpose of this study is to evaluate the amount of water absorption supplied by the pouring method and spraying method, to investigate the effects of water absorption on the thermal conductivity of an insulation material, and modeling the relation between water absorption and thermal conductivity. E-glass, a kind of glass fiber, and HYPERLITE, mainly composed of pearlite, are selected, to compare hygroscopic and insulation properties. E-glass is found to have much higher water absorptivity, compared to HYPERLITE. The thermal conductivity of the water-absorbed E-glass is increased by more than 150%, compared to that of no absorption, while variation of the thermal conductivity of HYPERLITE with water absorption is insignificant. A three-stage model of water absorption for thermal conductivity is developed, and the modeling results are found to be in good agreement with the experimental data.

칼집을 낸 현미의 수화 및 취반 특성

본 연구는 현미의 취반 시 물리적 특성을 개선하기 위하여 칼날로 일정 깊이 흠집을 낸 현미(0.07 및 0.20 mm SBR)와 일반 현미(NBR) 및 백미(NR)의 수분 흡수 특성, 취반 전 후의 무기질 함량, 취반 시 밥알의 물성 차이 및 엿기름에 의한 가수분해 정도를 측정하였다. 수침에 따른 수분함량, 부피 및 무게 증가량은 수침 210분이 지남에 따라 NBR<0.07 SBR<0.20 SBR=NR순으로 NR과 0.20 SBR이 유사한 수준을 나타내었다. 호화에 따른 쌀의 수분함량은 NR이 51.14%, 0.07 SBR이 42.53%, 0.20 SBR이 44.93%, NBR이 38.36%로 도정도 및 칼집 수준에 따라 유의성이 인정되었다(p<0.05). 호화에 따른 쌀의 경도 변화는 NR<0.20 SBR<0.07 SBR<NBR 순의 유의성이 인정되었다(p<0.05). 호화미의 가수분해 정도는 효소 반응 전과 비교하여 반응 6시간 후에 각각 3.28(NR), 1.71(NBR), 2.09(0.07 SBR) 및 2.23배(0.20 SBR) 증가하여 NBR<0.07 SBR<0.20 SBR<NR순이었다. 취반 전 후 무기질 함량은 백미와 현미군 사이에 차이가 뚜렷하였다. 이상의 결과를 종합하면 칼집 현미는 현미의 취반 시 단점을 보완할 뿐 아니라 영양 성분의 유실을 적게 하는 장점이 있어 현미 칼집 깊이의 적합한 수준이 0.20 mm 임을 확인하였다. In order to improve the physical properties of brown rice by hydration and cooking, the amount of water absorption, hardness, reducing sugar, and minerals were measured for rice (NR), brown rice (NBR), and scratched brown rice (SBR). The amounts of water absorption were present in the order of NBR<0.07 SBR<0.20 SBR=NR after 210 min. The moisture contents of gelatinization rice were significantly different by degree of milling and scratch. The hardness of gelatinization rice were present in the order of NR<0.20 SBR<0.07 SBR<NBR. The reducing sugars of gelatinization rice were increased by 3.28, 1.71, 2.09, and 2.23 times for NR, NBR, 0.07 SBR, and 0.20 SBR, respectively, as compared with the non-reaction sample after 6 hours. The minerals of rice before and after cooking were significantly different between NR and NBR. In conclusion, SBR is evenly prepared in the merit of NR and NBR, and the most appropriate level is 0.20 SBR.

STONE-GROUND WOOD PULP-REINFORCED POLYPROPYLENE COMPOSITES: WATER UPTAKE AND THERMAL PROPERTIES

Two of the drawbacks of using natural-based composites in industrial applications are thermal instability and water uptake capacity. In this work, mechanical wood pulp was used to reinforce polypropylene at a level of 20 to 50 wt. %. Composites were mixed by means of a Brabender internal mixer for both non-coupled and coupled formulations. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to determine the thermal properties of the composites. The water uptake behavior was evaluated by immersion of the composites in water until an equilibrium state was reached. Results of water absorption tests revealed that the amount of water absorption was clearly dependent upon the fiber content. The coupled composites showed lower water absorption compared to the uncoupled composites. The incorporation of mechanical wood pulp into the polypropylene matrix produced a clear nucleating effect by increasing the crystallinity degree of the polymer and also increasing the temperature of polymer degradation. The maximum degradation temperature for stone ground wood pulp–reinforced composites was in the range of 330 to 345 oC.

폴리비닐아세테이트(PVAc)를 이용한 복합공법의 수밀성능 향상에 관한 연구

본 연구에서는 시멘트에 작용하는 아크릴 코폴리머의 화학반응을 통해 강한 점착성과 유연성을 가지는 친환경적인 폴리비닐아세테이트(PVAc)를 이용하여 수밀성을 향상시키는 복합공법의 가능성을 알아보고자 하였으며, 이를 위한 실험 방법으로 1차로 실리케아트계 침투성 방수제를 도포 한 후, 2차로 PVAc를 혼입한 모르타를 도포한 후에 부착강도 및 흡수량에 대한 특성을 검토하였다. 이 실험 결과를 토대로 하여 현장 적용을 위한 Mock-up 부재를 제작하였고, 이 시험 부재에 대하여 복합공법을 적용한 후 실내 시험과 동일한 성능을 검토하였다. 또한, 탄산화 및 염소 이온 침투저항성 평가를 실시하여 내구성이 취약한 환경에 적합한지 여부를 검토 하였다. 그 결과 PVAc를 이용한 복합공밥을 적용한 시험체가 수밀성능이 가장 우수하였으며, 부착강도 또한 우수한 성능을 나타내었다. 또한, 간이 Mock-up 부재에 대한 성능평가에서 실내 시험과 동일한 경향을 보였으며, 압축강도 시험결과 보강 효과를 발휘함을 알 수 있었다. 탄산화 및 염소 이온 침투저항성 내구 성능 평가에서 가장 우수한 결과를 나타내어 지하구조물 및 해양구조물 등과 같은 취약한 지역에 적용이 가능함을 확인 할 수 있었다. In this study, hybrid method using polyvinyl acetate (PVAc) which has a strong adhesion and flexibility in which acrylic copolymer chemical-reaction reacts with cement, and is eco-friendly, is to improve the watertightness. The hybrid method is applied applied primarily waterproof stuff comprising silicate system and secondary mortar mixed with PVAc on the concrete surface. And then, in order to evaluate the performance, the properties of bond strength and amount of water absorption were measured. Based on the above experiments, mock-up specimens for field application were fabricated, and then the properties were evaluated as laboratory experiments. As the results, specimens cast from hybrid method using PVAc showed the best results on watertightness and bond strength. And also, with respect to experiment of mock-up specimens, the properties were in agreement with laboratory results. Especially, it could know that PVAc has strengthening effect from the results of the compressive strength. Due to outstanding results of carbonation depth and resistance to chloride ion penetration, it may be applied in weak areas such as underground and marine structures.

Mechanical and thermal properties and water absorption of jute fiber reinforced poly(butylene succinate) biodegradable composites

The poly(butylene succinate) (PBS) biodegradable composites reinforced with jute fibers were developed. The effect of fiber content (10–60wt%) on the properties and water absorption of jute/PBS biodegradable composites was studied. The effect of alkali, silane, and combined alkali and silane surface treatment on the properties and water absorption of jute/PBS composites was investigated. The mechanical properties of surface treated jute/PBS composites were significantly higher than those of untreated ones. Compared with alkali or silane treatment, the combined alkali and silane surface treatment showed better mechanical properties of jute/PBS composites. The best mechanical properties of jute/PBS composites were achieved at 50wt% in this study, which showed an increase in tensile strength by 517.9%, tensile modulus by 3529.8%, flexural strength by 302.6%, and flexural modulus by 1949.1% compared with those of PBS resin. Fractured surface morphologies of composite specimens exhibited an improvement of interfacial fiber–matrix adhesion in the composites reinforced with surface-treated jute fibers. The surface-treated jute/PBS composites having good fiber–matrix adhesion resulted in stable composites with better thermal stability than untreated jute/PBS composites. The water absorption amount of the composites increased with increasing the fiber content. The surface-treated jute/PBS composites showed relatively lower water absorption behavior compared to untreated ones.

The effect of water absorption on critical heat flux enhancement during pool boiling

A pool-boiling critical heat flux (CHF) correlation that can reflect the effect of capillary wicking on micro- and nano-structured surfaces was developed based on Kandlikar’s CHF correlation dealing with wettability. Capillary wicking tests were performed to examine the significant pool-boiling CHF enhancement on a zirconium surface due to anodic oxidation modification. The amount of water absorption was measured using a capillary tube. Compared with a bare or wettable surface, the micro- and nano-structured surfaces showed much higher absorption ability. The behavior was different for each surface. The amount of water absorption indicated the effective capillary wicking on the surface and was used to explain the CHF enhancement provided by the zirconium surfaces. The tendency toward water absorption, depending on the surface, agreed with the experimental CHF data. A simple and additional contribution to Kandlikar’s CHF correlation was proposed to account for the effect of capillary wicking. This modified correlation was in good agreement with CHF results from experiments.