Rheological Studies on Glycerol Plasticized Gelatin and Its Blends with Epoxidized Soybean Oil

Blends of gelatin(Ge)plasticized with varying amounts of glycerol(Gly),buffer solution pH 10 and epoxidized soybean oil(ESO)to enhance hydrophobicity were prepared by mixing and injection-molding.Blends were characterized by rheological tests and microscopy to select optimal conditions for scaling up their processing.The effect of each component on rheological response was analyzed using parallel plate geometry.Coating of gelatin specimens with PDMS during rheological tests led to reliable and reproducible results since water evaporation was prevented.A gradual increment in ESO concentration led to blends with increased degree of phase separation,as evidenced by optical and confocal microscopy.Limited compatibility between ESO and Ge increased viscosity at high ESO levels,but up to 10%Gly could be replaced with ESO without a significant variation of rheological behavior.

Plant Oil-Based Waterborne Polyurethanes: A Brief Review

The increasing pressure from consumers and policy makers to reduce the use of synthetic polymers,whose production contributes to the depletion of non-renewable resources and are usually non-biodegradable,has prompted the efforts to find suitable bio-based sources for the production of polymers.Vegetable oils have been a frequently spotted in this search because they are versatile,highly available and a low cost liquid biosource,which can be used in the synthesis of a wide plethora of different polymers and reactive monomers.Following the same idea of reducing the environmental stress,the traditional polyurethanes that are soluble in organic solvents have been targeted for replacement,particularly in applications such as adhesives and coatings,in which the solvent is released to the atmosphere increasing the air pollution.Instead,waterborne polyurethanes(WBPU),which are polyurethane dispersions(PUD)prepared in aqueous media,release benign water to the atmosphere during use as supported or self-standing films for different applications.In this brief review,the contributions to the development of WBPUs based on vegetable oils are discussed,focusing mainly on the contributions of the last decade.The synthesis of ionic and nonionic PUDs,their characterization and the properties of the resulting dried materials,as well as derived composite materials are considered.

Synthesis and evaluation of nickel cobalt ferrite magnetic ceramics employing two alternative routes

Ni_(0.5)Co_(0.5)Fe_(2)O_(4)(NCF)powders were obtained employing two alternative synthesis routes:solid-state reaction and Pechini’s methods.The ceramic powders were pressed and sintered in the temperature range of 1100℃ to 1250℃.Microstructural and structural properties were evaluated by SEM,XRD,and Raman spectroscopy.Magnetic hysteresis loops of sintered samples were also recorded.A secondary phase was observed in samples synthesized by Pechini’s method,whereas samples obtained by the solid-state reaction method,with the mechanochemical activation of the reagents,only produced the spinel structure.Magnetic properties of samples obtained by the solid-state method displayed higher magnetic saturations and lower coercive fields than those obtained from the Pechini’s method.

Zeolites for food applications:A review Cristian

Zeolites have been little investigated for food applications,despite their chemical composition is similar to clays and clay minerals,which have been extensively analyzed for various applications,including food.Zeolites can be distinguished from clay materials,since the former have a porous microstructure characterized by intracrystalline cavities and channels,while the latter have a laminar microstructure.The goal of this review paper was to give a comprehensive perspective in terms of the different food applications found so far for zeolites,namely:antimicrobial materials,ethylene scavengers,fillers for food packaging materials,food nanoreactors,food substance sensors,immobilizers and stabilizers of active compounds and enzymes,molecular sieves for the pretreatment of food samples,as well as intelligent food contact materials.The main food applications from zeolites are related to their good properties as adsorbent materials,and these properties can be altered and tuned by ion exchange,surface organo-modification,among others,for a specific designed application.Zeolites for food applications have been investigated primarily as antimicrobial materials,concentrators of target analytes and sensors for food substances.However,the other potential food applications indicated above from zeolites are booming,since they are harmless materials recognized by various organizations.