Polyester Binder Research Articles

Thermal Analysis and Stability of Boron/Potassium Nitrate Pyrotechnic Composition at 180 °C

Aerospace missions require that pyrotechnic compositions are able to withstand 180 °C. Therefore, this paper studies the thermal stability and output performance of boron/potassium nitrate (abbreviated BPN) used in pyrotechnic devices. Firstly, differential scanning calorimetry (DSC) and thermogravimetric (TG) tests are used to analyze the thermal reaction process of KNO3, boron, and BPN to qualitatively judge their thermal stability. Then, apparent morphology analysis, component analysis, and the p-t curve test, which is the closed bomb test to measure the output power of the pyrotechnic composition, are carried out with BPN samples before and after the high-temperature test to verify BPN stability at 180 °C. The weight change of boron powder caused by chemical reactions occurs above 500 °C. When the temperature is lower than the peak exothermic temperature of decomposition, no obvious chemical reaction occurs with KNO3, and only physical changes (crystal transformation and melting) occur. Combined with a verification test at 180 °C for two days, it is concluded that boron and KNO3 components are stable at 180 °C. With an increase in boron content, the thermal stability of BPN is improved, with the best performance achieved when the ratio is 25:75 (B:KNO3). BPN samples without binder have the best thermal stability. In a test at 180 °C for five days, the binder affects the weight loss and p-t curve of BPN, and BPN with fluororubber binder is better than BPN with unsaturated polyester binder.

Lipase catalyzed modification of functionalized polyester binders

Non-toxic coating formulations, i.e. without isocyanate, formaldehyde and toxic amines are a topic in the coating industries since decades. The replacement of cross-linking agents or functional groups to non-toxic compounds reduced often the mechanical properties of the coating film or just one toxic compounds are replaced by another toxic one. In the presenting work a biocatalytic route to functionalized polyester is presented forming reactive cyclic carbonates on the resin. The resin could be cross-linked by catalytic amount of amine to form a polyester-network with promising mechanical properties in comparison to polyester-melamine networks.

Intense pulse light sintering of an Ag microparticle-based, highly stretchable, and conductive electrode

This study proposes a highly stretchable, conductive electrode based on micro-sized Ag particles and Ag flakes incorporated into a polyester binder. The use of the microparticles in fabricating the stretchable electrode has several advantages over the spherical nanoparticles, namely, affordable, easier to synthesize, slower oxidation, and higher aspect ratio. Intense pulsed light (IPL) was employed to sinter the stretchable composite electrode printed on a polyurethane substrate. IPL was found to be an effective and fast sintering technique that lasts within seconds for stretchable electrodes consisting of Ag microparticles. The electrical and electromechanical properties were examined with varying the IPL energy intensities. The optimum IPL energy intensity was found to be 2 J/cm2 without damaging the substrate. The stretchable electrodes exhibited superior stretchability of 170% strain and high mechanical stability of over 1000 stretching cycles under 50% strain. The stretchable electrodes exhibited excellent bendability, as they could be bent up to 1 mm and withstand 1000 repetitive bending cycles at a bending radius of 2 mm. The electrodes also showed a robust static bending endurance during the 240 h test and excellent adhesion strength. The electromechanical properties of the stretchable electrode could be further enhanced by minimizing the pores and voids inside the electrode during the synthesis and sintering process.

Synthesis and Characterization of Binders for Propellants

The present work is devoted to the synthesis and characterization of polymeric binders for use in composite propellants. Polymeric binders hold together solid fuel and oxidant particles that constitute composite propellants, forming a solid elastic mass that is able to withstand thermal and mechanical stresses. Usually, the binder is also a fuel, working as a source of carbon and hydrogen for the propellant burning reaction. In the present study, polyester binders based on the reaction of green 1,2‐propanediol, 1,3‐propanediol, ethylene glycol, diethylene glycol, and 1,4‐butanediol with succinic acid were produced through two‐step polycondensations (esterification and transesterification), using the initial proportion of 4 (OH): 3 (COOH). Polymer samples were characterized with help of Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Matrix‐Assisted Laser Desorption Ionization Process (MALDI TOF) and Reaction Calorimetry (RC). The obtained results indicate that the use of the proposed polymeric binders can be advantageous for formulation of new green composite propellants.

Highly stretchable and conductive conductors based on Ag flakes and polyester composites

In stretchable electronics, the development of conductors that have high stretchability and low electrical resistance is a crucial technical issue. In this study, we developed a highly stretchable Ag conductor composed of Ag flakes and a polyester binder. We focused on the IR-curing technique to develop the stretchable Ag conductor, which was printed on the polyurethane elastomer substrate. The effects of the temperature and duration of curing on the electrical resistance and electromechanical properties of the Ag conductor were investigated. The electromechanical properties of the stretchable Ag conductor were evaluated in stretching, bending, and cyclic endurance tests. We achieved stretchable conductors with a low sheet resistance of 46 mΩ/sq., a superior stretchability of 150%, and a bending radius of 1 mm. The Ag conductor also exhibited outstanding mechanical durability in the cyclic stretching and bending endurance tests. In this study, the optimized IR-curing duration and temperature were 5 min and 130 °C, respectively. However, in future research, the curing duration could be further reduced by the optimization of the IR parameters. The results of the pencil hardness test and the peel-off adhesion test (i.e., the cross-cut test) indicated that the stretchable Ag conductor had excellent hardness and strength of adhesion between the conductor and the substrate.

Development and Life Cycle Assessment of Polyester Binders Containing 2,5-Furandicarboxylic Acid and Their Polyurethane Coatings

This work presents a new polyester binder based on 2,5-furandicarboxylic acid (FDCA) as precursors of polyurethane (PU) coatings. The new 100% bio-based structure is composed of four different monomers such as glycerine (Gly), 1,3-propanediol (1,3-PD), 2,5-furandicarboxylic acid (FDCA) and succinic acid (SA). The corresponding PU coating was obtained by crosslinking with a conventional polyisocyanate (Vestanat 1890/100). Evaluation of technological performances is present and benchmarked against partially bio-based (75% renewable carbon) polyester binder and fossil-based polyester binder, already developed in one of our previous work. The study showed a stiffer PU coating and a more hydrophilic character leading to better adhesion where a possible potential application may be interesting as an intermediate layer/primer in the field of metal coating (coil coating, automotive). Afterwards, the evaluation of the total impact of greenhouse gas emissions (GHG), the total non-renewable energy use (NREU) by the Life Cycle Assessment (LCA) for the new polyester binder are included on a cradle-to-gate approach, and considering an FDCA production process starting from sugar beet (primary data). The results showed a very noteworthy reduction in terms of GHG emissions (− 36 and − 79%) and a noticeable reduction impact in terms of NREU (− 38 and − 60%) compared to 75% bio-based and fossil-based polyester binders respectively. Moreover, a sensitivity analysis regarding sugar production from beet cultivation was developed through different LCA calculation methodologies. Those methodologies showed a not very significant difference between them.Graphical

A Research on Tensile Properties of Nonwoven Fabrics Produced from Staple Polyester and Sheath/Core Low Melting Staple Polyester Binder Fibres with Carding, Needle Punching and Pressing Machines

A Research on Tensile Properties of Nonwoven Fabrics Produced from Staple Polyester and Sheath/Core Low Melting Staple Polyester Binder Fibres with Carding, Needle Punching and Pressing Machines

Morphology and properties of poly(ethylene terephthalate) and thermoplastic polyester elastomer blends modified in the melt by a diisocyanate chain extender and filled with a short glass fiber

ABSTRACTThe structural features and rheological, mechanical, and relaxation properties of poly(ethylene terephthalate) (PET) blends with 7–50 wt % polyester thermoplastic polyester elastomer (TPEE), a block copolymer of poly(butylene terephthalate) and poly(tetramethylene oxide), chemically modified by a diisocyanate chain extender (CE) and reinforced with 30% glass fibers (GF) were studied. The composites were obtained by reactive extrusion with a twin‐screw reactor–mixer with a unidirectional rotation of screws. The molecular–structural changes in the materials were judged against data provided by differential scanning calorimetry, scanning electron microscopy, relaxation spectrometry, and rheological analysis of the melts. Regardless of the TPEE concentration in the blends with GF‐reinforced PET, the addition of CE resulted in the growth of the indices of the mechanical properties at straining, bending, and impact loading and an increase in the melt viscosity. In addition, an increase in the average length of short GFs in the composites and an intensification of interphase adhesion in the polyester binder–GF surface system were observed. The introduction of CE promoted a slowdown in PET crystallization in the composites and intensified the interphase adhesion in the binder–GF system at temperatures higher and lower than the PET glass‐transition temperature. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45711.

Electrically conductive palm oil-based coating with UV curing ability

Abstract Environmentally friendly products are gaining popularity recently, in line with the increasing global demands for green technology. UV-curable coating is one of them since it involves minimal, if any, emission of volatile organic compounds during the curing process. Besides, UV curing technology enables coatings to be cured within a much shorter time compared to the thermal curing process. The aim of this study is to produce an electrically conductive UV-curable coating which is environmentally friendly. Polyaniline is a polymer with excellent electrical conductivity and known to exhibit anti-corrosion properties through passivation. However, polyaniline itself is not a good coating binder, as it tends to produce a brittle film with poor adhesion properties. Therefore, in this work, palm oil-based polyester binder was synthesized and blended with polyaniline to produce an electrically active coating with improved film adhesion properties. The alkyd resin was formulated with a considerable amount of maleic acid formulation in order to render it UV curable. Both alkyd and polyaniline were characterized using FTIR, 1 H NMR, TGA, and UV-Vis. Some of the tests carried out to investigate the film properties of the coatings included the pencil hardness test, adhesion tape test, water and chemical resistant test, conductivity, and thermal stability. In addition, corrosion studies of the coatings on mild steels were determined using open circuit potential (OCP) values, Tafel analysis and electrochemical impedance spectroscopy (EIS).

Optical characterization and modelling of paint top-coatings for low-emittance applications

The study reports on characterization of low-infrared-emittance paint top-coatings for interior building applications in which the thermal radiation becomes important in comparison with thermal conductance. The top-coating that consist of a binder with aluminium flakes has been optically characterized in the infrared wavelength range in order to determine single flake and binder emittance from reflectance measurements. The single flake emittance was found to be 0.12 for non-leafing cornflake. The absorption coefficient that determines the binder emittance as a function of binder thickness was 0.060 [μm]−2 and 0.085 [μm]−2 for Lumiflon and polyester respectively. These results were used as parameters in a simple model of the flake-binder top-coating to investigate how the emittance of the top-coating was influence by the two components and compared with a state-of-art low-emittance commercial paint. It was found from the modelling that replacing the polyester binder with Lumiflon reduces the infrared emittance (at room temperature) from 0.36 to 0.30. Increasing flake reflectance from 0.88 to 0.96 and at the same time reduce flake thickness from 2 to 1μm gives an emittance of 0.20. However, the real samples prepared with Lumiflon showed a severe degradation caused by the flakes floating up closer to the surface which indicates a viscosity problem that needs to be solved for practical use. Thinner flakes with higher reflectance can be found if vacuum metallised pigments are used instead of ball-milled.

Bisphenol A based polyester binder as an effective interlaminar toughener

Bisphenol A based thermoplastic polyesters are commonly used in the industry as binders, or tackifiers, to produce cost-saving preforms in Liquid Composite Moulding processes such as Vacuum Assisted Resin Transfer Moulding (VARTM). However, it is often reported that the presence of these polyesters has a detrimental effect on the mechanical properties of the resulting composite laminates. In contrast, this study shows that interlaminar toughness can be increased without negatively affecting other properties by coating the reinforcing plies with a bisphenol A based thermoplastic polyester if some precautions are taken in mind.The polyester was added to an epoxy resin in order to study its effect on the thermophysical properties and fracture toughness of the bulk epoxy. The polyester molecules acted as a plasticizer for the epoxy resin when the polyester was added in low amounts. This increased the bulk fracture toughness of the epoxy resin by 30%. Polyester modified glass/epoxy laminates were produced and tested for Mode I interlaminar fracture toughness and flexural properties. The increased toughness of the epoxy matrix led to a 60% increased Mode I interlaminar fracture toughness of the laminates, without negatively affecting flexural stiffness and strength of the laminates.

Development of technology to introduce carbon nanotubes into a polyester-binder composition

Technological regimes of introducing carbon nanotubes (CNTs) into a polyester matrix composite are considered, and the properties of the obtained composition are studied. It is established that agglomerates that cannot be broken up by a mechanical stirring are formed at the moment of CNT wetting with the polyester binder. The use of an ultrasound disperser makes it possible to get rid of agglomerates but leads to enhanced porosity, with additional technological operations being necessary for reducing the latter.

Applications of High‐Nitrogen Energetics in Pyrotechnics: Development of Perchlorate‐Free Red Star M126A1 Hand‐Held Signal Formulations with Superior Luminous Intensities and Burn Times

AbstractPerchlorate‐free hand‐held signal illuminant formulations for the M126A1 red star parachute have been developed. The formulations exhibited longer burn times and higher luminous intensities compared to the US Army in‐service M126A1 formulation. The perchlorate‐free formulations derive their enhanced performance from the inclusion of strontium bis‐(1‐methyl‐5‐nitriminotetrazolate) monohydrate, the choice of magnesium used, and replacing a polyester binder system with an epoxy binder system.

Modification of polyester binders for glass fiber-reinforced plastics with phosphorus-containing metacrylates for reduction of composite flammability

Synthetic procedures for methacrylic derivatives of phosphorus acids are developed. Their copolymerization with unsaturated polyesters gives binders for low-flammable composite materials. Novel fiberglass plastics for shipbuilding are presented.

Water vapor properties of two hemp wools manufactured with different treatments

Hemp wools are environmentally friendly materials that are used for thermal insulation of building. These fibrous materials are the places of moisture transfer and storage that impact on thermal performances of the material. In this work, two kinds of hemp wool are studied: hemp wool with an organic binder (called HW1) and hemp-cotton wool with a polyester binder (called HW2). The investigations are based on water vapor sorption and on water vapor permeability measurements. The two kinds of hemp wool show similar sorption isotherm with quite high values of water content. The water vapor permeability is quite high too.

Structure–property correlations of flexible clear coats

In this paper thermomechanical and mechanical properties of various free clear coat films for coil-coated steel sheets were studied by dynamic mechanical analysis and tensile testing. To establish structure–property correlations, polyacrylate and polyester binder resins with varying molar mass and functionality were investigated. The clear coat films based on polyacrylate binders exhibited higher glass transitions values, crosslinking densities, elastic modulus and tensile strength values. For both resin types, a relationship of the properties glass transition temperature, crosslinking density, stiffness and tensile strength and the functionality considering the molar mass and the hydroxyl value of the resins was obtained. The elastic strain energy of the investigated brittle clear coat films depended mainly on the elastic modulus.

Flexible clear coats—Effect of curing conditions

The effect of curing at different conditions was investigated for flexible model clear coat films for coil coating applications. Based on a commercial polyester binder two formulations with isocyanate based crosslinking agents (hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI)) were prepared. The clear coats were baked at laboratory (145 °C) and industrial processing (300 °C) conditions. While for high temperature curing the baking time was kept constant at 30 s, the curing time at 145 °C, which is above the deblocking temperature of the crosslinking agents, was varied from 10 to 90 min. The clear coat films were characterized as to their thermomechanical and mechanical properties by dynamic mechanical analysis (DMA) and by tensile testing. Regarding DMA loading in tensile and penetration mode was performed. By baking at 300 °C for 30 s and at 145 °C for at least 20–45 min similar thermomechanical and mechanical properties were obtained. Thus, it was shown that it is possible to prepare specimens at a moderate curing temperature under laboratory conditions, which are comparable to clear coat films baked at processing conditions. While HDI-cured films exhibited lower glass transition temperatures and a ductile to brittle transition depending on curing time at 145 °C, for the investigated IPDI crosslinked films about 20 °C higher glass transition temperatures and a brittle deformation behavior independent of curing time were obtained. Both clear coat formulations baked at 145 °C to free films exhibited a similar relationship between crosslinking density and curing time. For DMA in tensile and penetration mode a good agreement of the determined glass transition temperatures as a function of curing time was established. Whereas DMA in tensile mode was not applicable for rather brittle films, DMA in penetration mode proved to be a more appropriate testing method for the determination of glass transition temperatures of coat films or even coatings applied to a substrate.

Flow behavior of unsaturated polyester resin—Microsized 17‐4PH stainless steel powder—Feedstocks

AbstractFor the realization of stainless steel parts carrying either surface relief microstructures or possessing dimensions in submillimeter‐range the different variants of micro injection molding are suitable replication techniques, followed by thermal postprocessing like debinding and sintering. With respect to warpage‐free sintered parts the initial solid load in the feedstock should be as large as possible. A reduction of the binder viscosity enables a reduction of the feedstock viscosity; hence, larger solid loads can be achieved. Using an unsaturated polyester binder, diluted with different amounts of the reactive thinner styrene, feedstocks with a solid content up to 46 vol% were realized. The influence of the filler on the feedstock viscosity, the maximum accessible load and the flow activation energy was investigated intensely. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers

414 ナノ粒子の大面積自己整列とエッチングマスク応用に関する研究(T03-3 マイクロナノ理工学:nmからmmまでのテクスチャリングの創成と機能(3),大会テーマセッション,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

Self-assembly of nano-particles has been applied to large-scale Si substrates and PET films. Dip coating technique successfully allows φ300nm-SiO_2 particles to be uniformly assembled on Si wafer of 100 millimeters diameter with small variations in the particles coverage. The suspension containing acrylic or polyester binder enables the particle coverage to be higher with the drawing speed, when the drawing speed is above specific value. It is estimated to be about 100 μm/s. It has been demonstrated that reactive ion etching selectively etches the opening among SiO_2 phrticles to fabricate nanostntctures onto Si surface. The morphology of etched surface has an army of pillars of several hundreds nanometers height with specific pitch according to the particle diameter. The φ110nm SiO_2 particles are also assembled on PET films. The effective index of refraction is approximately 1.22 in the assembled particles, so that it increases the transmittance of PET film.

Chemically Produced Toner Containing a Binary Polyester Binder

The fuser roller is commonly used in electrophotograhic machines such as copiers, laser printers and multifunctional printers to fix toner image on paper. For improving printing speeds, image gloss and energy consumptions, an increasing number of printers are designed to adopt polyester toner. Polyester toner, with its low fusing temperatures, is aimed to accommodate fuser rollers operated at low temperatures to reduce energy consumption. Although polyester toner has the above advantages, low fusing temperatures on the other hand can cause hot-offset defects on the fuser roller. This paper reports the study of chemically produced toner (CPT) consisting of a binary polyester binder. The toner was prepared by phase-separation/aggregation (PSA) method. It was found a balance of low-temperature fixing and anti-offset characteristics can be achieved by incorporating a binary polymer mixture of low- and high-molecular weight polyesters. The addition of wax was also used to provide an option to tune the fixing and anti-offset characteristics. Wax content, however, was found to exhibit some threshold value, above which wax tends to separate from the toner and the resultant wax leaks can contaminate associated printer parts to cause streaking defects.