Search

Poly(vinyl acetate), PVAc, adhesives are commonly used for wood bonding; however, they are fossil-based and the final products usually do not have a sufficient water resistance for more durable applications. In this study we prepared an adhesive formulation by grafting VAc from chitosan using emulsion polymerization, chitosan-graft-PVAc. Thereby, we could decrease the fossil-based content of the adhesive and at the same time significantly improve the water resistance. Chitosan by itself has very good bonding properties as a wood adhesive, especially regarding water resistance; however, very low solid contents of the adhesive formulation can be achieved due to a very high viscosity of chitosan adhesives. In our chitosan-graft-PVAc adhesives, we explored two chitosan samples with different molecular weights, by using as-received chitosan and hydrolyzing it to a lower molecular weight. The chitosan fractions in the adhesives prepared with a higher molecular weight chitosan were 15, 20 and 25 wt%. However, due to the high viscosity, a solid content higher than 17 wt% could not be achieved for these adhesives. Sufficient bond strengths were achieved when the adhesive was applied in 122 g/m2 solid spread rate. In order to decrease the viscosity, we used hydrolyzed chitosan, with a lower molecular weight, to allow for a higher adhesive solid content, 34 wt%, and for a higher chitosan fraction, 40 wt%. In the adhesive with 40 wt% chitosan and 17 wt% solid content, all VAc was grafted from chitosan. This decreased the molecular mobility of the chains, leading to a lower susceptibility to plastic creep in the adhesive which contributes to the final bond strength. The dry and wet strengths of the specimens bonded with adhesives containing chitosan were higher than the strength of the specimens bonded with the reference PVAc adhesive., QC 20240926

Research in smart textiles is growing due to the increased demand from the healthcare sector and people's urge to keep track of and analyze the signals and metrics from their bodies. Electrically conductive filaments are the most fundamental material for smart textiles. These filaments can be imbued with functionalities and useful in fields like energy storage, sensing, and actuation. To be able to meet the requirements that the latter applications require, fabrication techniques must be developed to provide better processability and sustainability in a cost-effective manner. Here, a mixture of a conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), and biobased cellulose nanofibrils (CNFs) was used to spin filaments utilizing a water-based process. These filaments show electrical conductivities up to 150 S/cm and tensile stiffness of 20 GPa. Interestingly, the PEDOT aligned to a similar degree as the CNFs during the spinning process without a drawing step, which is hypothesized to be caused by the attachment of PEDOT on the CNFs. Lastly, the filaments were tested in an organic electrochemical transistor (OECT) configuration, which resulted in a working device with an on/off ratio approaching 1500. Furthermore, the OECT exhibited stable behavior when changing temperature (20-80 °C) and relative humidity (40-80%). This aqueous spinning method, resulting in filaments with robust electronic properties in different temperature and humidity environments, show greats promise for future innovative smart textiles., QC 20230308

Mixtures of polyadipate of 1,4-butanediol polyol and different small amounts (0.01–0.10 wt%) of graphene oxide (GO) were added during the synthesis of waterborne polyurethane urea dispersions (PUDs) carried out with the acetone method. The addition of 0.02–0.04 wt% GO increased the T-peel strength of plasticized poly (vinyl chloride)/PUD/plasticized poly (vinyl chloride) joints whereas the addition of 0.05–0.10 wt% GO increased the single lap-shear strength of stainless steel/PUD/stainless steel joints. The improved adhesion of the PUDs containing GO was ascribed to the creation of covalent interactions between the surface groups on the GO surface and the NCO groups of the isocyanate during prepolymer formation, creating new urethane groups; during the phase inversion, the covalently bonded GO sheets were embedded between the polyurethane urea chains inside the PUD particles, this changed the degree of phase separation between the hard and the soft segments. When more than 0.04 wt% GO was added, some GO particles cannot be covalently bonded to the prepolymer during the PUD synthesis but they agglomerated and physically “trapped” between the polyurethane urea chains. As a consequence, the adhesion properties of the PU + GO films were different in the PU films containing 0.01–0.04 wt% GO and the ones containing 0.05–0.10 wt% GO.

Mixtures of polyadipate of 1,4-butanediol polyol and different small amounts (0.01–0.10 wt%) of graphene oxide (GO) were added during the synthesis of waterborne polyurethane urea dispersions (PUDs) carried out with the acetone method. The addition of 0.02–0.04 wt% GO increased the T-peel strength of plasticized poly (vinyl chloride)/PUD/plasticized poly (vinyl chloride) joints whereas the addition of 0.05–0.10 wt% GO increased the single lap-shear strength of stainless steel/PUD/stainless steel joints. The improved adhesion of the PUDs containing GO was ascribed to the creation of covalent interactions between the surface groups on the GO surface and the NCO groups of the isocyanate during prepolymer formation, creating new urethane groups; during the phase inversion, the covalently bonded GO sheets were embedded between the polyurethane urea chains inside the PUD particles, this changed the degree of phase separation between the hard and the soft segments. When more than 0.04 wt% GO was added, some GO particles cannot be covalently bonded to the prepolymer during the PUD synthesis but they agglomerated and physically “trapped” between the polyurethane urea chains. As a consequence, the adhesion properties of the PU + GO films were different in the PU films containing 0.01–0.04 wt% GO and the ones containing 0.05–0.10 wt% GO.

Several waterborne polyurethane urea dispersions (WPUUs) were prepared by mixing different amounts of two waterborne polyurethane urea dispersions made with polyester (WPUU-Polyester) and polycarbonate diol (WPUU-PCD). Their crystallinity, thermal, rheological, viscoelastic and adhesion properties depended on the segmented structure and degree of phase separation which were determined by the different content of the parent dispersions. The PUU films made with WPUU-Polyester+WPUU-PCD mixtures containing more than 50 wt% of WPUU-PCD showed higher hard segments content and lower degree of phase separation, and the addition of 25 wt% of WPUU-Polyester imparted crystallinity to the polyurethane urea due to the interactions between the carbonate groups in the soft segments. The differences in the degree of phase separation and crystallinity of the PUU films made with WPUU-Polyester+WPUU-PCD mixtures were evidenced by the increase in the glass transition temperature associated to the alpha relaxation of the soft segments, and the higher modulus at the cross-over between the storage and loss moduli. Excellent adhesion was obtained in plasticized PVC/WPUU/plasticized PVC joints, and a cohesive failure of PVC was always obtained, irrespective of the composition of WPUU-Polyester+WPUU-PCD mixtures. Furthermore, the adhesion of surface-chlorinated vulcanized styrene-butadiene (SBR) rubber/WPUU+5 wt% hardener/roughened leather joints were high and similar in all joints and a dominant cohesive failure in the rubber substrate was produced. The accelerated ageing by immersion in water at 70 °C during different times showed that the polyurethane urea film and the surface-chlorinated vulcanized SBR rubber/WPUU+5 wt% hardener/roughened leather joint made with WPUU-PCD dispersion were not affected, but noticeable hydrolytic degradation of the ester units in the soft segments was produced in PUU-Polyester and, to a less extent, in PUU-50Polyester/50PCD films and adhesive joints.

Several waterborne polyurethane urea dispersions (WPUUs) were prepared by mixing different amounts of two waterborne polyurethane urea dispersions made with polyester (WPUU-Polyester) and polycarbonate diol (WPUU-PCD). Their crystallinity, thermal, rheological, viscoelastic and adhesion properties depended on the segmented structure and degree of phase separation which were determined by the different content of the parent dispersions. The PUU films made with WPUU-Polyester+WPUU-PCD mixtures containing more than 50 wt% of WPUU-PCD showed higher hard segments content and lower degree of phase separation, and the addition of 25 wt% of WPUU-Polyester imparted crystallinity to the polyurethane urea due to the interactions between the carbonate groups in the soft segments. The differences in the degree of phase separation and crystallinity of the PUU films made with WPUU-Polyester+WPUU-PCD mixtures were evidenced by the increase in the glass transition temperature associated to the alpha relaxation of the soft segments, and the higher modulus at the cross-over between the storage and loss moduli. Excellent adhesion was obtained in plasticized PVC/WPUU/plasticized PVC joints, and a cohesive failure of PVC was always obtained, irrespective of the composition of WPUU-Polyester+WPUU-PCD mixtures. Furthermore, the adhesion of surface-chlorinated vulcanized styrene-butadiene (SBR) rubber/WPUU+5 wt% hardener/roughened leather joints were high and similar in all joints and a dominant cohesive failure in the rubber substrate was produced. The accelerated ageing by immersion in water at 70 °C during different times showed that the polyurethane urea film and the surface-chlorinated vulcanized SBR rubber/WPUU+5 wt% hardener/roughened leather joint made with WPUU-PCD dispersion were not affected, but noticeable hydrolytic degradation of the ester units in the soft segments was produced in PUU-Polyester and, to a less extent, in PUU-50Polyester/50PCD films and adhesive joints.

The stability of polyacrylate and polyester based aqueous dispersions designed for ultrathin coating of extruded plastic films, especially bi-axially oriented polyethylene terephthalate (BOPET), was studied. Also, the effect of the gemini surfactant based defoaming/wetting agent on the properties of the dispersions was examined. The addition of the defoaming/wetting agent resulted in reducing the surface free tension of the polyacrylate and polyester dispersion by 15% and 20%, respectively and the initial foam height by 60% and 15%, respectively. At the same time, the agent addition did not compromise the temperature and pH stability of the dispersions. Such modified dispersion can be utilized for ultrathin coating of plastic film used for packaging, to improve their processability, printability, and metallization.

Waterborne adhesives for rubber to metal bonding have been available since 1990. However, published information about their formulation has been limited, as proprietary restrictions are exercised by companies. As a consequence, the way these adhesives interact with substrates has not been studied extensively. With the aim of investigating the effect the components of a waterborne adhesive have on rubber to metal bonding, fractional factorial and surface response methodologies of design of experiments were employed in this study. Twenty six formulations were prepared with a polychloroprene latex as the adhesive polymer. Viscosity, wettability and non-volatile solids content were measured with each liquid adhesive, while the mechanical strength was evaluated by applying a tensile mechanical stress over cured solid adhesive films. Adhesion properties were evaluated by using a single lap-shear test on metal to metal joints and a pull-out test on rubber to metal joints. The results showed that the components with the largest relative influence on cohesive and adhesives forces were tackifier resin, silicon dioxide and polychloroprene latex type. In order to better understand the contributions of these variables, mathematical models correlating them with the response variables were obtained. This study is valuable in explaining how, through statistical methods, a waterborne adhesive for rubber to metal bonding can be formulated with a reasonably low number of experiments.

Waterborne adhesives for rubber to metal bonding have been available since 1990. However, published information about their formulation has been limited, as proprietary restrictions are exercised by companies. As a consequence, the way these adhesives interact with substrates has not been studied extensively. With the aim of investigating the effect the components of a waterborne adhesive have on rubber to metal bonding, fractional factorial and surface response methodologies of design of experiments were employed in this study. Twenty six formulations were prepared with a polychloroprene latex as the adhesive polymer. Viscosity, wettability and non-volatile solids content were measured with each liquid adhesive, while the mechanical strength was evaluated by applying a tensile mechanical stress over cured solid adhesive films. Adhesion properties were evaluated by using a single lap-shear test on metal to metal joints and a pull-out test on rubber to metal joints. The results showed that the components with the largest relative influence on cohesive and adhesives forces were tackifier resin, silicon dioxide and polychloroprene latex type. In order to better understand the contributions of these variables, mathematical models correlating them with the response variables were obtained. This study is valuable in explaining how, through statistical methods, a waterborne adhesive for rubber to metal bonding can be formulated with a reasonably low number of experiments.

The stability of polyacrylate and polyester based aqueous dispersions designed for ultrathin coating of extruded plastic films, especially bi-axially oriented polyethylene terephthalate (BOPET), was studied. Also, the effect of the gemini surfactant based defoaming/wetting agent on the properties of the dispersions was examined. The addition of the defoaming/wetting agent resulted in reducing the surface free tension of the polyacrylate and polyester dispersion by 15% and 20%, respectively and the initial foam height by 60% and 15%, respectively. At the same time, the agent addition did not compromise the temperature and pH stability of the dispersions. Such modified dispersion can be utilized for ultrathin coating of plastic film used for packaging, to improve their processability, printability, and metallization.

Waterborne adhesives for rubber to metal bonding have been available since 1990. However, published information about their formulation has been limited, as proprietary restrictions are exercised by companies. As a consequence, the way these adhesives interact with substrates has not been studied extensively. With the aim of investigating the effect the components of a waterborne adhesive have on rubber to metal bonding, fractional factorial and surface response methodologies of design of experiments were employed in this study. Twenty six formulations were prepared with a polychloroprene latex as the adhesive polymer. Viscosity, wettability and non-volatile solids content were measured with each liquid adhesive, while the mechanical strength was evaluated by applying a tensile mechanical stress over cured solid adhesive films. Adhesion properties were evaluated by using a single lap-shear test on metal to metal joints and a pull-out test on rubber to metal joints. The results showed that the components with the largest relative influence on cohesive and adhesives forces were tackifier resin, silicon dioxide and polychloroprene latex type. In order to better understand the contributions of these variables, mathematical models correlating them with the response variables were obtained. This study is valuable in explaining how, through statistical methods, a waterborne adhesive for rubber to metal bonding can be formulated with a reasonably low number of experiments. © 2016 Elsevier Ltd

Waterborne adhesives for rubber to metal bonding have been available since 1990. However, published information about their formulation has been limited, as proprietary restrictions are exercised by companies. As a consequence, the way these adhesives interact with substrates has not been studied extensively. With the aim of investigating the effect the components of a waterborne adhesive have on rubber to metal bonding, fractional factorial and surface response methodologies of design of experiments were employed in this study. Twenty six formulations were prepared with a polychloroprene latex as the adhesive polymer. Viscosity, wettability and non-volatile solids content were measured with each liquid adhesive, while the mechanical strength was evaluated by applying a tensile mechanical stress over cured solid adhesive films. Adhesion properties were evaluated by using a single lap-shear test on metal to metal joints and a pull-out test on rubber to metal joints. The results showed that the components with the largest relative influence on cohesive and adhesives forces were tackifier resin, silicon dioxide and polychloroprene latex type. In order to better understand the contributions of these variables, mathematical models correlating them with the response variables were obtained. This study is valuable in explaining how, through statistical methods, a waterborne adhesive for rubber to metal bonding can be formulated with a reasonably low number of experiments. © 2016 Elsevier Ltd

Waterborne adhesives for rubber to metal bonding have been available since 1990. However, published information about their formulation has been limited, as proprietary restrictions are exercised by companies. As a consequence, the way these adhesives interact with substrates has not been studied extensively. With the aim of investigating the effect the components of a waterborne adhesive have on rubber to metal bonding, fractional factorial and surface response methodologies of design of experiments were employed in this study. Twenty six formulations were prepared with a polychloroprene latex as the adhesive polymer. Viscosity, wettability and non-volatile solids content were measured with each liquid adhesive, while the mechanical strength was evaluated by applying a tensile mechanical stress over cured solid adhesive films. Adhesion properties were evaluated by using a single lap-shear test on metal to metal joints and a pull-out test on rubber to metal joints. The results showed that the components with the largest relative influence on cohesive and adhesives forces were tackifier resin, silicon dioxide and polychloroprene latex type. In order to better understand the contributions of these variables, mathematical models correlating them with the response variables were obtained. This study is valuable in explaining how, through statistical methods, a waterborne adhesive for rubber to metal bonding can be formulated with a reasonably low number of experiments. © 2016 Elsevier Ltd

Moisture content in furan bonded sand and water based coatings can be one of the main causes for gas related defects in large cast iron parts. Moisture diffusion coefficients for these materials are needed to precisely predict the possible moisture levels in foundry moulds. In this study, we first compare two different experimental methods that can be used to determine moisture diffusion coefficients. Then, we determine diffusion coefficients for water based coatings and for different types of furan binders and we investigate the effects of compaction, dust levels and temperature. Finally, we provide an example on how it is possible to apply this knowledge to estimate moisture variation in a sand mould during production.

We show that water-based porosimetry (WBP), a facile, simple, and nondestructive porosimetry technique, accurately evaluates both the pore size distribution and throat size distribution of sacrificially templated macroporous alumina. The pore size distribution and throat size distribution derived from the WBP evaluation in uptake (imbibition) and release (drainage) mode, respectively, were corroborated by mercury porosimetry and X-ray micro-computed tomography (μ-CT). In contrast with mercury porosimetry, the WBP also provided information on the presence of "dead-end pores" in the macroporous alumina., QC 20131122

Polyurethane anionic adhesives were synthesized as waterborne polyurethane dispersions (PUDs) by modified dispersing procedure, using isophorone diisocyanate, dimethylol propionic acid, ethylenediamine as a chain extender and a range of soft segments with various macrodiols proportions. The soft segment was formed by replacing poly(propylene glycol) (PPG) as polyether polyol with polycarbonate diol (PCD), as polyester polyol. The effect of the macrodiols proportions of soft segment on the thermal properties of polyurethane films was measured by thermogravimetry analyses (TGA) and differential scanning calorimetry (DSC) methods. The infrared spectroscopy (FTIR) was used for evaluating the degree of phase separation. The results showed that phase separation between hard and soft segments of poly(ester-urethane) is more significant than of poly(ether-urethane). The phase separation degree of polyurethane dispersion significantly affected the glass transition temperature (T-g) and film properties. While the phase separation degree increased, T-g proportionally decreased, but the hardness and gloss of the dried films increased, as expected. However, thermal stability was influenced by the molecular weight of used polyols and chemical structure of the polyols, and it was described by the effect of oxygen content, and interaction between the soft and hard segment, and the soft segment composition. The soft segment can be achieved with a proper selection, in order to fine-tune the performance of waterborne polyurethane dispersion, considering certain practical application. (C) 2012 Elsevier Ltd. All rights reserved.

[ES] En el presente trabajo se ha llevado a cabo una revisión de los métodos y materiales consolidantes de pinturas en la historia y en la actualidad y se ha realizado una comparativa entre tres grupos de adhesivos. En el proceso experimental de esta investigación han sido analizadas diferentes mezclas adhesivas, todas ellas con base acuosa., [EN] This work was carried out a review of methods and materials consolidatings used throughout history and today and performed a comparison between three groups of adhesives. In the experimental process of this research have been analyzed different adhesive mixtures, all with water-based.

[ES] En el presente trabajo se ha llevado a cabo una revisión de los métodos y materiales consolidantes de pinturas en la historia y en la actualidad y se ha realizado una comparativa entre tres grupos de adhesivos. En el proceso experimental de esta investigación han sido analizadas diferentes mezclas adhesivas, todas ellas con base acuosa., [EN] This work was carried out a review of methods and materials consolidatings used throughout history and today and performed a comparison between three groups of adhesives. In the experimental process of this research have been analyzed different adhesive mixtures, all with water-based.

Polyurethane anionic adhesives were synthesized as waterborne polyurethane dispersions (PUDs) by modified dispersing procedure, using isophorone diisocyanate, dimethylol propionic acid, ethylenediamine as a chain extender and a range of soft segments with various macrodiols proportions. The soft segment was formed by replacing poly(propylene glycol) (PPG) as polyether polyol with polycarbonate diol (PCD), as polyester polyol. The effect of the macrodiols proportions of soft segment on the thermal properties of polyurethane films was measured by thermogravimetry analyses (TGA) and differential scanning calorimetry (DSC) methods. The infrared spectroscopy (FTIR) was used for evaluating the degree of phase separation. The results showed that phase separation between hard and soft segments of poly(ester-urethane) is more significant than of poly(ether-urethane). The phase separation degree of polyurethane dispersion significantly affected the glass transition temperature (T-g) and film properties. While the phase separation degree increased, T-g proportionally decreased, but the hardness and gloss of the dried films increased, as expected. However, thermal stability was influenced by the molecular weight of used polyols and chemical structure of the polyols, and it was described by the effect of oxygen content, and interaction between the soft and hard segment, and the soft segment composition. The soft segment can be achieved with a proper selection, in order to fine-tune the performance of waterborne polyurethane dispersion, considering certain practical application. (C) 2012 Elsevier Ltd. All rights reserved.

[ES] En el presente trabajo se ha llevado a cabo una revisión de los métodos y materiales consolidantes de pinturas en la historia y en la actualidad y se ha realizado una comparativa entre tres grupos de adhesivos. En el proceso experimental de esta investigación han sido analizadas diferentes mezclas adhesivas, todas ellas con base acuosa., [EN] This work was carried out a review of methods and materials consolidatings used throughout history and today and performed a comparison between three groups of adhesives. In the experimental process of this research have been analyzed different adhesive mixtures, all with water-based.

Digital printing using high-speed inkjet technology puts heavy demands on paper's ability to rapidly absorb the liquid. This is important for both the runability during the printing process and for the print quality. In this article, the dynamics of inkjet droplet absorption and penetration is discussed. The LucasWashburn equation has been applied to experimental results from inkjet printing on paper. The ink absorption on different paper grades is discussed in terms of the physical properties of the surface such as surface energy, surface roughness and porosity. The results of this study indicate that ASA used as internal sizing reduces the absorption speed of water based dye inkjet ink and that evaporation affects the result. The Lucas-Washburn equation can be used to some extent for describing micro-scale droplet absorption into paper, depending on the properties of the paper., Next Generation substrates for inkjet printing

Digital printing using high-speed inkjet technology puts heavy demands on paper's ability to rapidly absorb the liquid. This is important for both the runability during the printing process and for the print quality. In this article, the dynamics of inkjet droplet absorption and penetration is discussed. The LucasWashburn equation has been applied to experimental results from inkjet printing on paper. The ink absorption on different paper grades is discussed in terms of the physical properties of the surface such as surface energy, surface roughness and porosity. The results of this study indicate that ASA used as internal sizing reduces the absorption speed of water based dye inkjet ink and that evaporation affects the result. The Lucas-Washburn equation can be used to some extent for describing micro-scale droplet absorption into paper, depending on the properties of the paper., Next Generation substrates for inkjet printing

Digital printing using high-speed inkjet technology puts heavy demands on paper's ability to rapidly absorb the liquid. This is important for both the runability during the printing process and for the print quality. In this article, the dynamics of inkjet droplet absorption and penetration is discussed. The LucasWashburn equation has been applied to experimental results from inkjet printing on paper. The ink absorption on different paper grades is discussed in terms of the physical properties of the surface such as surface energy, surface roughness and porosity. The results of this study indicate that ASA used as internal sizing reduces the absorption speed of water based dye inkjet ink and that evaporation affects the result. The Lucas-Washburn equation can be used to some extent for describing micro-scale droplet absorption into paper, depending on the properties of the paper., Next Generation substrates for inkjet printing

Digital printing using high-speed inkjet technology puts heavy demands on paper's ability to rapidly absorb the liquid. This is important for both the runability during the printing process and for the print quality. In this article, the dynamics of inkjet droplet absorption and penetration is discussed. The LucasWashburn equation has been applied to experimental results from inkjet printing on paper. The ink absorption on different paper grades is discussed in terms of the physical properties of the surface such as surface energy, surface roughness and porosity. The results of this study indicate that ASA used as internal sizing reduces the absorption speed of water based dye inkjet ink and that evaporation affects the result. The Lucas-Washburn equation can be used to some extent for describing micro-scale droplet absorption into paper, depending on the properties of the paper., Next Generation substrates for inkjet printing

Digital printing using high-speed inkjet technology puts heavy demands on paper's ability to rapidly absorb the liquid. This is important for both the runability during the printing process and for the print quality. In this article, the dynamics of inkjet droplet absorption and penetration is discussed. The LucasWashburn equation has been applied to experimental results from inkjet printing on paper. The ink absorption on different paper grades is discussed in terms of the physical properties of the surface such as surface energy, surface roughness and porosity. The results of this study indicate that ASA used as internal sizing reduces the absorption speed of water based dye inkjet ink and that evaporation affects the result. The Lucas-Washburn equation can be used to some extent for describing micro-scale droplet absorption into paper, depending on the properties of the paper., Next Generation substrates for inkjet printing

Tailoring the chemical and physical properties of molecular materials by rational design to increase density, reduce toxicity, or to improve overall stability characteristics continues to be an important research endeavor. Achieving this by the structural modification of neutral organic compounds offers a limited scope of opportunities. Organic-like solid and liquid salts significantly enhance this flexibility for properties tailoring by pairing different classical heterocyclic cations with a plethora of different counteranions. Over the past 25 years, this is re-emphasized with salts based on neutral heterocyclic compounds. Rekindled interest in this approach appears to initiate with the unique properties exhibited by the hygroscopic binary 1-ethyl-3-methyl-1,3-imidazolium (EMIM) chloroaluminate salt followed by a subsequent report of non-hygroscopic, air stable, binary EMIM salts containing other anions. Later, triazolium cations are used to form salts with common anions. We now report the synthesis and characterization of salts containing heterocyclic cations that are paired with two different three-dimensional polyhedral borane/carborane anions, [B12H12](2-) and [CB11H12](-), as well as a new aqueous preparation method that does not require air-free techniques., Prepared in collaboration with the Department of Chemistry and Biochemistry, University of Maryland, College Park, MD and the Department of Chemistry, Colorado State University, Fort Collins, CO. For publication in Organic Letters, v11 n12 p2623-2626, May 2009. The original document contains color images. All DTIC reproductions will be in black and white.

This revision to the Joint Test Report for Validation of Alternatives to Lead-Containing Dry Film Lubricants for Antigalling/Antifretting, Antiseizing, and Assembly Aid Applications includes an additional test requirement for humidity resistance. This requirement was identified by turbine engine original equipment manufacturers based on experience in evaluating water-based dry film lubricants (DFLs) for antigalling/antifretting applications. Exposure of some DFLs to hot, humid conditions has the potential to rehydrate the binder, rendering the DFL as a "wet" coating that is susceptible to removal. This report was prepared by the NDCEE. This report was prepared on behalf of, and under guidance provided by the Propulsion Environmental Working Group (PEWG) and the Joint Group on Pollution Prevention (JG-PP). The structure, format, and depth of technical content of the report were determined by the JG-PP Working Group, PEWG, original equipment manufacturers, and other Government technical representatives in response to the specific needs of this project., Engineering and Technical Services for Joint Group on Acquisition Pollution Prevention (JG-PP). Sponsor report no. NDCEE-CR-2004-013.

Solution deposition processes for the production of thin multi-element metal oxide films continue with great interest and varied success. Solution deposition via either sol-gel or MOD (Metal Organic Decomposition) methods are of interest due to the ability to produce a wide variety of compositional products at low capital investment cost. The sol-gel method generally uses hydrolytically sensitive metal alkoxides as the starting materials. Manipulation of the reagents and different hydrolysis rates for multi-element mixtures are issues. The MOD method utilizes large organic acid metal salts as the starting materials. In general, MOD solutions are more hydrolytically stable than the sol-gel solutions. MOD process challenges include large quantities of carbon to be decomposed during the firing, shrinkage and stress of the thin films, variable chemistry in synthesis of the starting materials (especially when the starting materials for the MOD precursors are metal alkoxides), and long reaction times for the synthesis. For both the sol-gel and MOD precursors, toxic and volatile organic chemical (VOC's) solvents are employed as the vehicle. This paper will review the chemistry-related issues to production of consistent high-quality metal oxide films via the MOD process. The fabrication of thin Ba(x)Sr(1-x)TiO3 (BST) films is described. A new class of MOD precursor has been implemented using polyether acids as the organic vehicle. These new materials are both water stable and water soluble. High quality BST thin films made from these precursors are described and capacitors made from these films are compared to the aliphatic acid MOD materials. Improved capacitors using lower resistance electrodes and interconnects are described, as well as devices designed specifically for our specific application., This article is from the Materials Research Society symposium proceedings, v720 p23-28, 2002. Prepared in cooperation with Pennsylvania State Univ. University Park, PA; Univ. of Pittsburgh, Pittsburgh, PA. This article is from ADA410712 Materials Research Society Symposium Proceedings; Volume 720. Materials Issues for Tunable RF and Microwave Devices III Held in San Francisco, California on April 2-3, 2002

Citrikleen is a terpene based solvent and its component is derived from d-limonene or pine tree. It is also a biodegradable water based solvent. Because of this property, US Army has used this environmentally friendly solvent as a purging solution in all military fuel tanks including Heavy Expanded Mobility Truck (HEMTT) for the last eight years. Recently, TACOM Logistic Assistance Representative (LAR) reported that Citrikleen solvent damages rubber seal equipped in Tank and Pump Units (TPUs), HEMTTs, and 5000 gallons of fuel delivery trucks. To clarity this problem, a seal compatibility test was conducted with Citrikleen solvents according to the ASTM D 471 test method for Rubber Property-Effect of Liquids. To draw a baseline for this evaluation, two fuel samples (i.e., JP-8 and DF-2) were tested along with Citrikleen. In addition, three more solvent were also tested to make a comparison against Citrikleen solvent Based on the seal compatibility test results, this paper summarizes test results and findings, and redefines Citrikleen solvent as a purging solution for military fuel tanks.

Formulation studies using commercial Saran microspheres and halogenated latex binder led to the development of aqueous intumescent coatings. When modified with certain flame retardant additives, compositions impart excellent flame spread resistance to wood substrates. Microsphere/latex compositions modified with decabromodiphenyl oxide provide good flame insulation properties for steel panels; panel backside temperatures remained below 1000 F during flame exposure of phosphatized steel panels coated with intumescent composition. Latex/microsphere intumescent coatings show good quality and appearance when applied to wood. Further work on primer systems is needed, however, to eliminate cracking and discoloration of coatings when applied to steel panels.