Effects Of MgCl2 Research Articles

Hydration mechanism of hydrated magnesium citrate: The effects of MgCl2

AbstractIn this study, the evolutions of kinetic parameters, such as hydration temperature, pH, and electrical conductivity, were observed to investigate the hydration mechanism of hydrated magnesium citrate (HMC). Additionally, the effects of MgCl2 on the hydration behavior of HMC and the working performance of its bonded castables were also investigated. The results show that the hydration mechanism of HMC is dissolution–precipitation, and its hydration product is magnesium citrate tetrahydrate [Mg(H2O)6] [MgC6H5O7(H2O)n]2∙(8‐2n)H2O. The hydration process of HMC is controlled by the concentration of the C6H6O72− ions. MgCl2 could inhibit the ionization of HMC, thereby delaying the hydration progress of HMC. The second exothermic peak was delayed from 1 to 4.8 h with increased MgCl2 content to 1.0 wt.%. The working performance of HMC‐bonded castables could be improved by adding MgCl2. After adding MgCl2, the setting time, flow value, and cold modulus of rupture of HMC‐bonded castables increased by 26.7%, 25.2%, and 8.8%, respectively, while the porosity decreased by 12%.

Effects of MgCl2 on sludge anaerobic digestion: Hydrolysis, acidogenesis, methanogenesis, and microbial characteristics

Back diffused draw salt affects the anaerobic digestion performance in a forward osmosis membrane bioreactor. Previous studies have established the influence of MgCl2 on sludge anaerobic digestion; however, its effects on individual phases, such as hydrolysis, acidogenesis, and methanogenesis remain unclear. This study investigates the influence of different concentrations of MgCl2 on these stages of anaerobic digestion and compares variations in methane production under different substrates. The findings demonstrate that adding MgCl2 significantly enhances sludge hydrolysis. At a concentration of 50 g/L, the soluble chemical oxygen demand increases by 265.2 %, although with unstable reactions. MgCl2 significantly affects the production of fatty acids. Specifically, the production of acids was enhanced when the concentration of MgCl2 was below 20 g/L, while it was inhibited when the concentration exceeded 50 g/L. The highest concentration of acetic acid recorded is 1991.28 mg/L, which represents an 83.5 % increment. In contrast, methane production shows a higher susceptibility to MgCl2, experiencing inhibition at concentrations exceeding 1 g/L. The inhibitory concentration for methane production is lower than for acid production. The study also observes significant differences in microbial structure, particularly in Methanogen. When using different substrates, the predominant orders of methanogen are Methanobacteriales for tests with acid solution as a feed and Methanosarcinales for tests with waste sludge as a feed, respectively. Analyses of metabolic pathways reveal that carbon dioxide and acetic acid are the most prevalent pathways in terms of abundance. In summary, MgCl2 has varying effects on various stages of anaerobic digestion of sludge.

Effect of MgCl2 on CO2 sequestration as hydrates in marine environment: A thermodynamic and kinetic investigation with morphology insights

Oceanic hydrate-based CO2 sequestration (HBCS) holds great promise for achieving carbon neutrality. However, the presence of inorganic salts, particularly MgCl2 besides NaCl, in seawater can significantly impact the formation rate and the stability of CO2 hydrate. In this study, experimental investigations were conducted to examine the thermodynamics, kinetics, and the resulting morphological features of CO2 hydrate in the presence of MgCl2, covering mass fractions ranging from 0 to 5.0 wt%. The experimental findings reveal that MgCl2 exerts a thermodynamic inhibitory effect with its inhibitory capacity increasing with higher mass fractions. The solubility model of CO2 in MgCl2 solution was modified, demonstrating a gradual weakening of CO2 solubility as MgCl2 mass fraction increases. Additionally, the growth kinetics of CO2 hydrate decreases with increasing MgCl2 mass fraction. Regarding CO2 hydrate morphology, it was observed that at low mass fractions of MgCl2 (<1.0 wt%), a dense hydrate film rapidly formed at the gas-liquid interface after CO2 hydrate nucleation, hindering the further conversion of CO2 into hydrate. Conversely, at higher mass fractions (>3.0 wt%), CO2 hydrate exhibits a more porous and slurry-like structure, facilitating more gas-liquid contact and mass transfer, thereby enhancing the conversion of CO2 into hydrate. During hydrate dissociation, a salt-removal effect associated with CO2 hydrate formation was observed, leading to the accumulation of concentrated electrolyte (MgCl2) and facilitating CO2 hydrate dissociation. These findings have implications for understanding the CO2 hydrate formation and dissociation in the presence of MgCl2 relevant in the subsea environment and can contribute to the development of effective hydrate-based CO2 sequestration strategies.

Nitrogen and phosphorus recovery from sludge treatment by supercritical water gasification coupled with struvite crystallization

To recover nitrogen and phosphorus in the process water from the treatment of sewage sludge using supercritical water gasification (SCWG), struvite crystallization was coupled into the process. K2CO3 was added in SCWG to increase syngas production, and improve the migration of N and P into the aqueous phase, which was favorable for the subsequent struvite crystallization. The effect of MgCl2 and pH on the removal of N, P, and COD as well as the purity of struvite was studied during the struvite crystallization process. The results showed that the syngas yield significantly increased from 9.1 mol/kg to 14.2 mol/kg with K2CO3 addition. In the struvite crystallization process, pH had significant impact on the crystallization and the purity of struvite, while MgCl2 had only a slight effect. The highest N and P removal of 94.8 % and 99.5 % from the aqueous phase was achieved by struvite crystallization at pH 8. The obtained struvite had a high purity of 93.3 %, and the heavy metal content in struvite was lower than the value of standard, so that the obtained struvite sample can be used as fertilizer. This research could be a guideline to utilize the process water with high nutrients from sludge treatment.

Hydrothermal carbonization combined with thermochemical treatment of sewage sludge: Effects of MgCl2 on the migration of phosphorus and heavy metal

Phosphorus (P) is a non-regenerative and finite raw material. Due to its decreasing availability, and to protect the environment, recycling methods are needed. With the focus on closing nutrient cycles, sewage sludge (SS) is a potential source for P recovery. The objective of this study was to produce a mineral P-reach fertilizer. For this purpose, the treatment of SS in a multi-stage process, consisting of a hydrothermal carbonization (HTC) and thermochemical post-treatment was examined and compared with a direct thermochemical treatment. The focus was on the transformation of P and the migration of the heavy metals during the processes. In addition, the role of MgCl2 as an additive was examined. During the HTC, most of the P remained in the HTC-char, so that the P content increased in the HTC-char compared with the SS. The addition of MgCl2 to the process resulted in lower transportation rates of P in the liquid phase and higher P solubilities in water, citric acid, and alkalic ammonium citrate out of the solid phase. The thermochemical treatment of SS and the HTC-chars further concentrated P in the ash. Retention rates of >97% were achieved, and P2O5 contents in the ash were as high as ∼16 wt-%. The presence of the additive resulted in (i) higher retention rates of P in the ashes (ii) higher P-solubility and (iii) higher removal rates of easily volatile heavy metals such as Pb and Zn, and the treatment of HTC-char favored these effects compared with the direct treatment of SS.

The effect rules of MgCl2 and NaCl on the properties of potato starch: The inflection point phenomenon

The effects of MgCl2 and NaCl concentrations on potato starch were analysed. With an increase in MgCl2 and NaCl concentrations from 0 to 4 mol/L, the gelatinisation properties, crystalline properties, and sedimentation rate of potato starch all showed a trend of rising first and then falling (or falling first and then rising). The inflection points of the effect trends were observed at 0.5 mol/L. This inflection point phenomenon was further analysed. At higher salt concentrations, starch granules were found to absorb external ions. These ions enhance the hydration of starch molecules and promote starch gelatinisation. When NaCl and MgCl2 concentrations were increased from 0 to 4 mol/L, the starch hydration strength increased 52.09 and 65.41 times, respectively. At lower salt concentrations, the ions that naturally exist in starch granules seep out of the granules. The exudation of these ions may cause a certain degree of damage to the native structure of starch granules.

Effect of MgCl2 on electrophoretic deposition of TbF3 powders on Nd-Fe-B sintered magnet

Using electrophoretic deposition (EPD) method, the TbF3 powders were deposited on the surface of sintered Nd-Fe-B magnets, and the effects of MgCl2 on electrophoretic deposition and grain boundary diffusion were investigated. The results show that addition of 5 wt% MgCl2 can significantly improve the EPD efficiency and improve the adhesion of the coating by releasing local stress through the formation of special gully morphology. Combining with Biesheuvel equation, the effects of suspension concentration, voltage and time on EPD amount were studied. The Biesheuvel equation can be simplified as γ = AUSct/L, and A (= 0.0141–0.0144) in this experiment was calculated to achieve the quantitative calculation of EPD amount. After heat treatment of 875 °C × 10 h + 500 °C × 1 h, the coercivity of 48H (7 mm) sintered magnet with 0.3 wt% TbF3 increases from 18.5 to 22.4 kOe, with an increase of 21.1%. The core–shell structure was observed by a back-scattered scanning electron microscope (BSE-SEM), which proves that the addition of MgCl2 has no adverse effect on the grain boundary diffusion of Nd-Fe-B sintered magnets.

Microscopic mechanisms of inorganic salts affecting the performance of aqueous foams with sodium dodecyl sulfate: View from the gas–liquid interface

Inorganic salts contained in wellbore accumulations have a significant impact on the suitability and effectiveness of foam draining technology in gas wells. Despite many studies on the effects of such salts on the stability of water-based foams generated by surfactant, the findings are not conclusive due to the differences in surfactant structures and research methods used. In order to gain a better understanding of the influence of inorganic salt types and concentrations on foam systems containing sodium dodecyl sulfate (SDS), a combined experimental and molecular simulation-based approach was used. The experimental results showed that MgCl2 significantly improves the stability of the SDS foam system, while NaCl greatly improves its liquid carrying capacity. Distinguishing from the traditional classification including foam generation, gas coarsening and bubble rupture, the process of foam system from generation to rupture was divided into three new stages, as manifest in foam generation, liquid drainage and gas transfer. In conjunction with molecular dynamics simulations, the effect of MgCl2 and NaCl on these three stages was explored. In addition, the microscopic mechanisms by which MgCl2 and NaCl influenced the stability and liquid-carrying properties of the SDS foam system were clarified. It was found that MgCl2 improved the foam stability by reducing the gas–liquid interfacial tension and enhancing the strength of the interface containing SDS, while NaCl improved the liquid-carrying capacity of the SDS foam system through hydration. The understanding of this study is of great importance for the application of aqueous foams with SDS in upstream natural gas industry.

Effects of Different Coagulants on Quality Characteristics and Flavor Components of Tofu

To study the quality characteristics and flavor components of tofu made with different coagulants, the effects of MgCl2, CaSO4, lactic acid, acetic acid, GDL and fermented soy whey (FSW) on the yield, texture, chromatic aberration, microstructure and volatile flavor compounds of tofu were analyzed by texture profile and scanning electron microscopy analysis and solid phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). The moisture content and yield of the FSW tofu and GDL tofu were significantly higher than those of other coagulants tofu (P<0.05). The acetic acid tofu had the highest hardness (244.04 mN) and chewiness (176.34 mJ) and the lowest L* value (82.77). CaSO4 tofu and GDL tofu had dense network structure, while lactic acid tofu had rough surface and pores. In addition, a total of 100 volatile flavor compounds of soymilk and tofu made with different coagulants, including alcohols, aldehydes, ketones, esters, acids and phenols, were detected. The total volatile compounds in soy milk were significantly higher than those in tofu with different coagulants (P<0.05). FSW tofu had higher numbers of volatile compounds and lower total amount of the compounds of beany flavor. The cluster analysis showed that the volatile flavor characteristics of lactic acid tofu, acetic acid tofu and MgCl2 tofu had high similarity, while CaSO4 tofu and GDL tofu had high similarity. The principal components analysis shows that the volatile flavor compounds contributed greatly to the flavor of tofu were 2, 4-nonadienal, (E)-2-octenal, 1-hexanol, (E)-2-decenal and (E, E)-2, 4-decadienal. Sensory evaluation showed that CaSO4 tofu and FSW tofu were superior to other coagulants tofu. Therefore, the type of coagulant has significant effects on the yield, texture, chromatic aberration, microstructure and volatile flavor compounds of tofu, and CaSO4 and FSW can make tofu with better quality and flavor, and their tofu have higher consumption appeal.

Effect of MgCl2 and GdCl3 on ORAI1 Expression and Store-Operated Ca2+ Entry in Megakaryocytes.

In chronic kidney disease, hyperphosphatemia upregulates the Ca2+ channel ORAI and its activating Ca2+ sensor STIM in megakaryocytes and platelets. ORAI1 and STIM1 accomplish store-operated Ca2+ entry (SOCE) and play a key role in platelet activation. Signaling linking phosphate to upregulation of ORAI1 and STIM1 includes transcription factor NFAT5 and serum and glucocorticoid-inducible kinase SGK1. In vascular smooth muscle cells, the effect of hyperphosphatemia on ORAI1/STIM1 expression and SOCE is suppressed by Mg2+ and the calcium-sensing receptor (CaSR) agonist Gd3+. The present study explored whether sustained exposure to Mg2+ or Gd3+ interferes with the phosphate-induced upregulation of NFAT5, SGK1, ORAI1,2,3, STIM1,2 and SOCE in megakaryocytes. To this end, human megakaryocytic Meg-01 cells were treated with 2 mM ß-glycerophosphate for 24 h in the absence and presence of either 1.5 mM MgCl2 or 50 µM GdCl3. Transcript levels were estimated utilizing q-RT-PCR, protein abundance by Western blotting, cytosolic Ca2+ concentration ([Ca2+]i) by Fura-2 fluorescence and SOCE from the increase in [Ca2+]i following re-addition of extracellular Ca2+ after store depletion with thapsigargin (1 µM). As a result, Mg2+ and Gd3+ upregulated CaSR and blunted or virtually abolished the phosphate-induced upregulation of NFAT5, SGK1, ORAI1,2,3, STIM1,2 and SOCE in megakaryocytes. In conclusion, Mg2+ and the CaSR agonist Gd3+ interfere with phosphate-induced dysregulation of [Ca2+]i in megakaryocytes.

Effect of various salt concentrations on the ruminal parameters of goats

The objective of this study was to evaluate the effects of various concentrations of sodium chloride (NaCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2) on the growth and in vitro fermentation of cellulolytic, glycolytic, and amylolytic microorganisms from the rumen of a goat. Six concentrations of each salt were tested separately, namely 0 mg/dL, 100 mg/dL, 200 mg/dL, 400 mg/dL, 800 mg/dL, and 1600 mg/dL in the culture medium. The experiments were conducted in a completely randomized design, in a 6 x 3 factorial arrangement of salt concentration and substrate (starch, cellulose, and glucose) with three replications of each treatment combination. Concentrations of microbial protein, ammonia (NH3-N), and volatile fatty acids (acetate, propionate, and butyrate) were measured. A quadratic effect of CaCl2 concentration on the production of microbial protein was observed in the cellulose medium. The effect of MgCl2 on NH3-N production in the cellulose medium decreased linearly. Propionate concentration decreased linearly with increasing levels of NaCl and MgCl2 in the media containing starch. There was a decreasing linear effect of MgCl2 on the concentration of butyrate in the media containing glucose. In conclusion, concentrations of NaCl and CaCl2 up to 1,600 mg/dL did not affect the microbial activity of starch, cellulose, and glucose-fermenting organisms. However, the microbial activity of starch-fermenting microbes was inhibited at salt concentrations above 800 mg/dL. Thus, brackish water could be used by goats in semiarid regions, but its use should be managed carefully so that it does not have a negative impact on rumen microbial populations.Keywords: cellulose, glucose, saline water, starch, ruminants

Effects of MgCl2 and Mg(NO3)2 loading on catalytic pyrolysis of sawdust for bio-oil and MgO-impregnated biochar production

For high-quality utilization of biomass resources, co-production of bio-oil and MgO-impregnated biochar from catalytic pyrolysis of Mg-loaded biomass samples is a prospective approach. In this study, the effects of MgCl2 and Mg(NO3)2 loading on catalytic pyrolysis of sawdust for production of high value-added bio-oil and biochar, as well as the catalytic pyrolysis process mechanism were explored. The thermal degradation process behavior and the pyrolysis products of non-condensable gas, bio-oil and biochar were obtained by thermogravimetric analyzer (TGA) and lab-scale fixed-bed reactor system. The product properties were analyzed and characterized by gas chromatography (GC), gas chromatography-mass spectrometry (GCMS), N2 adsorption-desorption, X-rays diffraction (XRD) and transmission electron microscopy (TEM). The obtained results indicated that the loading of Mg salts favored the thermal degradation process of catalytic pyrolysis due to the weakened hydrogen-bonding networks and disrupted the crystalline structures. The enhanced cross-linking and repolymerization reactions of pyrolysis intermediates by the catalytic effect of Mg resulted in the increased non-condensable gas and biochar yields and the decrease of bio-oil yield. The loading of Mg salts also resulted in the decreased CO yield and increased CO2 yield. The relative contents of ketones and furans increased, and the relative contents of phenols and sugars decreased for Mg-loaded SD samples in bio-oil. In addition, the Mg salts loading also favored the formation of developed pore structure and uniformly dispersed MgO nanoparticles in obtained biochar. In general, catalytic pyrolysis of MgCl2-loaded or Mg(NO3)2-loaded sawdust is a feasible method to obtain high value-added bio-oil and MgO-impregnated biochar products.

Investigation of Corrosion of 304 Stainless, Inconel 625, and Haynes 230 in a Chloride-Salt-Based Thermal Storage Medium

One of the critical challenges for latent heat thermal energy storage systems in concentrating solar power applications is corrosion of metallic alloys as containment and heat transfer fluid tube materials in corrosive salts at high temperatures. In this study, the effects of MgCl2 on the corrosion of stainless steel 304, Inconel 625, and Haynes 230 alloys were investigated through embedded metal samples in the graphite foam/MgCl2 storage medium. Four experimental testing modules were fabricated, and experimental tests were conducted under controlled environment by heating the testing modules to and keeping them at 750 °C for 100, 200, 500, and 1000 h. The estimated corrosion rates based on the weight losses for stainless steel 304, Inconel 625, and Haynes 230 were 94, 9, and 8 μm/year, respectively. The fitted equations for the loss of the thickness as functions of the exposure time show that the corrosion rates decrease with the exposure time. The results on the corrosion zones or depths and chromium segregation ranges of the experimental samples are also presented.

Effect of MgCl2 on the Corrosion Behavior of Copper Under Periodic Wet/Dry Cycle Condition

The corrosion behaviors of copper under periodic wet/dry cycle conditions were investigated. The characteristics of the corrosion product formed on copper were analyzed by x-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and in situ electrochemical impedance spectroscopy. Weight loss results showed that the corrosion of copper under an MgCl2 deposition condition was more severe than that under NaCl. The main corrosion products formed on the tested sample under NaCl deposition condition consisted of Cu2Cl(OH)3 and Cu2O, while those under the MgCl2 deposition condition consisted of Cu2Cl(OH)3 and Mg2(OH)3Cl·4H2O. In the case of the NaCl deposition condition, a two-layered structure formed during the corrosion process. However, the corrosion product layer formed on copper under the MgCl2 deposition condition had an extremely loose structure. The effect of MgCl2 on the corrosion mechanism of copper is discussed.

MgCl2 and its applications in organic chemistry and biochemistry: a review.

MgCl2 has been reported to be a versatile reagent especially as a Lewis acid catalyst in a variety of organic transformations including the preparation of heterocyclic compounds, the protection of functional groups and condensation reaction. Also the use of MgCl2 in the preparation of metallic magnesium and the application of magnesium chloride in biochemistry such as anesthetic for cephalopods, the separation of serum high-density lipoprotein, effect of MgCl2 on rabbit bronchial smooth muscle, antimicrobial properties of magnesium chloride and effect of MgCl2 on the quality of life for patients with fibromyalgia have been reported. Therefore, in this article the use of MgCl2 in organic chemistry and biochemistry is reviewed. MgCl2 has been reported to be a versatile reagent especially as a Lewis acid catalyst in a variety of organic transformations including the preparation of heterocyclic compounds, the protection of functional groups and condensation reaction. Also the use of MgCl2 in the preparation of metallic magnesium and the application of magnesium chloride in biochemistry such as anesthetic for cephalopods, the separation of serum high-density lipoprotein, effect of MgCl2 on rabbit bronchial smooth muscle, antimicrobial properties of magnesium chloride and effect of MgCl2 on the quality of life for patients with fibromyalgia have been reported. Therefore, in this article the use of MgCl2 in organic chemistry and biochemistry is reviewed.

Effects of MgCl2 on the gasification kinetics of petroleum coke

ABSTRACTMgCl2 is used as catalysts for petroleum coke-CO2 gasification. The effect of catalyst addition amount and gasification temperature on petroleum coke-CO2 gasification is studied by using thermogravimetric analyzer. It is shown that magnesium chloride has a catalytic effect on petroleum coke gasification. At the same temperature, the time required for complete gasification of petroleum coke decreases with the increase of catalyst dosage. There is a limit to the amount of catalyst added, and the best amount of magnesium chloride is 5%. The kinetics model of petroleum coke catalytic gasification is described by using the homogeneous model, the shrinkage model, and the Gaussian model, respectively. Compared with the gasification reaction activation energy calculated by the conversion method. It is shown that the shrinkage model can better describe the dynamic characteristics of petroleum coke catalytic gasification.

Highly mesoporous activated carbon synthesized by pyrolysis of waste polyester textiles and MgCl2: Physiochemical characteristics and pore-forming mechanism

Abstract Activation-pyrolysis of textile wastes was considered a sustainable technique to fabricate activated carbon. Highly mesoporous activated carbon was prepared from waste polyester textiles by employing MgCl2 as the activation and template agents. The influences of different preparation conditions on textual property and crystalline structure of carbon were identified by N2 adsorption-desorption isotherms and X-ray diffraction. The optimum pyrolysis temperature, time and mixing ratio for MgCl2/waste polyester textiles are 900 °C, 1.5 h and 5:5 with the carbon thus obtained manifested a surface area of 1307 m2/g, total pore volume of 3.56 cm3/g of which 98% is mesopore. The effect of MgCl2 on the full-cycle pyrolysis pathway of waste polyester textiles was systematically investigated by various characterization methods to explore the pore-forming mechanism of activated carbon. The results demonstrated that MgCl2 was capable of catalyzing the dehydrogenation, decarboxylic and cross-linking reaction of waste polyester textiles and inhibited the formation of tars during pyrolysis process, indicating that the addition of MgCl2 was conducive to the formation of carbonaceous materials and open pores. Meanwhile, acted as the template, MgO particles derived from the decomposition of MgCl2 could develop massive homogeneous mesopores in the carbon matrix.

MgCl2: The Key Ingredient to Improve Chloride Containing Electrolytes for Rechargeable Magnesium-Ion Batteries

The effect of MgCl2 on a series of chloride containing magnesium electrolytes was investigated. In the presence of extra MgCl2, the electrochemical properties of Grignard reagents (RMgCl, R = Ph, Et, iPr) were significantly improved, and the advantage of MgCl2 was further demonstrated in Mg-Mo6S8 rechargeable batteries with improved capacities and much smaller over-potentials. MgCl2 was then further proven to be a powerful reagent to improve the performance of well-established strong Lewis acid derived magnesium electrolytes including the “all-phenyl” complex (APC) and alkoxide-based magnesium electrolytes. The results suggest that MgCl2 salt is a very important species to benefit all chloride containing electrolytes for rechargeable magnesium-ion batteries.

Volumetric interactions of a series of α-amino acids in aqueous magnesium chloride solutions at 278.15, 288.15, 298.15, and 308.15 K

In this work, the partial molar volumes of glycine, l-alanine, l-valine, l-serine, and l-threonine in aqueous solutions of magnesium chloride at 0.0, 0.1, 0.3, 0.7, and 1.0 molal are addressed between 278.15 and 308.15 K. Volumes of transfer were obtained, following the rank serine > glycine ≈ threonine > alanine > valine. Differently, the hydration numbers follow the sequence serine > valine > alanine > threonine > glycine, and dehydration of the amino acids is observed, rising the temperature or salt molality. The data suggest that interactions are mainly pairwise, between the ions and charged/hydrophilic groups of the amino acids. Within the Friedman and Krishnan formalism, a group-contribution scheme has been successfully applied to the pairwise volumetric interaction coefficient. Finally, the dehydration effect of MgCl2 on glycine, alanine, and serine has been predicted applying empirical correlations developed before, showing satisfactory results.

Effect of magnesium chloride hexahydrate on thermal and mechanical properties of starch/PVA films

Starch/poly(vinyl alcohol) (PVA) blend films were prepared from the aqueous solutions containing starch, PVA and magnesium chloride hexahydrate (MgCl2.6H2O). The interaction between MgCl2.6H2O and starch/PVA was studied by Fourier transform infrared spectroscopy. The plasticising effect of MgCl2.6H2O on starch/PVA film was studied by scanning electron microscopy (SEM), X-ray diffraction, thermogravimetric analysis, dynamic mechanical analysis and tensile testing respectively. The water content of starch/PVA films increased with the content of MgCl2.6H2O. The absorbed water can act as the plasticiser for starch/PVA film. The crystals of starch and PVA were destroyed, and the crystallinity of starch/PVA film decreased with the plasticising effect of MgCl2.6H2O and water. SEM micrographs showed that the compatibility between starch and PVA improved with the addition of MgCl2.6H2O. The toughness of starch/PVA film increased with the content of MgCl2.6H2O.