Dimethylol Propionic Acid Content Research Articles

Synthesis, Morphology, and Particle Size Control of Acidic Aqueous Polyurethane Dispersions.

A range of charge-stabilized aqueous polyurethane (PU) dispersions comprising hard segments formed from hydrogenated methylene diphenyl diisocyanate (H12MDI) with dimethylolpropionic acid (DMPA) and ethylenediamine, and soft segments of poly(tetramethylene oxide) of different molecular weights are synthesized. Characterization of the dispersions by mass spectrometry, gel permeation chromatography, small-angle X-ray scattering, atomic force microscopy, and infrared spectroscopy shows that they are composed of PUs self-assembled into spherical particles (primary population) and supramolecular structures formed by hydrogen-bonded H12MDI and DMPA acid-rich fragments (secondary population). Analysis of the scattering patterns of the dispersions, using a structural model based on conservation of mass, reveals that the proportion of supramolecular structures increases with DMPA content. It is also found that the PU particle radius follows the predictions of the particle surface charge density model, originally developed for acrylic statistical copolymers, and is controlled by hydrophile (DMPA) content in the PU molecules, where an increase in PU acidity results in a decrease in particle size. Moreover, there is a critical fractional coverage of hydrophiles stabilizing the particle surface for a given polyether soft-segment molecular weight, which increases with the polyether molecular weight, confirming that more acid groups are required to stabilize a more hydrophobic composition.

Synthesis and application of flame retardant self‐matting aqueous polyurethane dispersion

AbstractTo address the issues of insufficient film smoothness, and flammability of aqueous polyurethane dispersions (PUD) prepared by adding matting agents, two hydrophilic chain extenders, dimethylolpropionic acid (DMPA) and sodium 2‐[(2‐aminoethyl)amino] ethanesulphonate (A95), were used to regulate the particle size of the emulsion while using FRC‐6 flame retardant as a small molecule chain extender to prepare a self‐matting and flame retardant PUD. Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscope, and atomic force microscopy were used to structurally characterize the latex films. The results showed that as theR‐value (NCO/OH molar ratio) and soft segment content decreased, the prepolymer viscosity increased, making it difficult to emulsify and reducing the glossiness of the film. Moreover, an initial increase in DMPA content led to a decrease in film glossiness, followed by an increase. Increasing the molar ratio of A95 sulfonic acid salt‐based chain extender to EDA affected the glossiness of the film, with a 2:8 molar ratio of A95: ethylenediamine (EDA) resulting in a glossiness of the film of 6.5%. The addition of reactive flame retardant diethyl bis (2‐hydroxyethyl) aminomethyl phosphonate (FRC‐6) increased the branching content in the prepolymer, improved the flame retardancy of the film, and reduced its glossiness. As a result, the self‐prepared PUD had a flat film with a glossiness as low as 6.0% and a flame retardancy rating of level 4.

Facile fabrication of high performance hydrophilic anti-icing polyurethane methacrylate coatings cured via UV irradiation

In this article, high performance hydrophilic anti-icing coatings with carboxyl groups were facilely fabricated via UV curing polyurethane methacrylate prepolymers, which were prepared through polyaddition of isophorone diisocyanate (IPDI), poly(propylene glycol) (PPG), dimethylolpropionic acid (DMPA) and 2-hydroxypropyl methacrylate (HPMA) gradually in acetone (A series prepolymer) or isobornyl acrylate (IBOA) (B series prepolymer), and finally treated with triethylamine (TEA). The structures of A series prepolymer and the corresponding cured coating were confirmed via various techniques. The anti-icing performance of the cured coatings was investigated by ice freezing delay test, ice adhesion strength test, water contact angle and water absorption tests, and DSC test. Based on the testing results, the anti-icing behavior was defined as the incomplete icing of water on hydrophilic surface to weaken the interface adhesion. The ice adhesion strength firstly decreased as the DMPA content increased. At DMPA content of 5 %, the coating displayed a stable and very low ice adhesion strength of 40 kPa even after 25 times of icing (at −12 °C) and de-icing (at 25 °C) cycling. At even higher DMPA content, the ice adhesion strength improved because of the anchoring effect of the ice. Moreover, when IBOA was used as reactive diluent and participated in the polymerization with the prepolymers, the obtained B series coatings could have much improved mechanical properties, together with low ice adhesion strength. The facile fabrication process, excellent anti-icing performance and adjustable mechanical properties should make the coatings suitable for various purposes.

Optimization of the water-based polyurethane with acrylate terminal process in nylon fabrics application using the Taguchi-based gray relational analysis method

This study synthesized the water-permeable and hydrophobic property of water-based polyurethane (WPU) and applied it to nylon fiber-based functional textiles. Specifically, poly-stearyl acrylate (PSA) homopolymers with different molecular weights were used as end-capping agents in the WPU to form water-based polyurethane with acrylate terminal (WPUA). In the WPUA process, dimethylacetamide was adopted as a neutralizing agent to form a stable WPUA emulsion. The effects of the design parameters, such as the hydrophilic ionic group dimethylol propionic acid (DMPA), the PSA molecular weight and content, were set as the control factors and are analyzed by the Taguchi method and gray relational analysis (GRA). The water-repellent characteristic, water vapor permeability (WVP) and fabric flexural rigidity were considered as performance parameters as multi-qualities. The Taguchi method was based on the analysis of variance and implemented orthogonal arrays for experimental design. Each performance parameter was optimized independently. Then, the performance parameters were optimized together with GRA. According to the experimental results, the most important factor for the water-repellent characteristic, WVP and fabric flexural rigidity is the DMPA content, followed by the PSA molecular weight and content. The corresponding results showed that in the optimal parameter combination, the content of DMPA was 30.8 phm (parts per hundred monomer by weight), the PSA molecular weight was 3000 g/mol and the PSA content was 4 phm. After WPUA padding, the water contact angle of the water-repellent nylon was 135.3°, the WVP was 2271.7 g/m2/day and the flexural rigidity was 2.7 cm.

Development of clean performance-tunable waterborne polyurethane using acetyl tributyl citrate for transferable holographic films

Scalable and transparent polyether-based waterborne polyurethane (WPU) thin films that adhere firmly to Al nanofilm but not to PET film without release agents have been designed and prepared. In order to realize cleaner production, eco-friendly acetyl tributyl citrate (ATBC) instead of toxic additives like N-methylpyrrolidone was introduced into polymerization system as both an effective dispersant of dimethylolpropionic acid crystal as hydrophilic chain extender and a viscosity thinner of the synthesized precursors to promote homogeneous hydrophilic extension reaction in the absence of toxic catalysts. The appropriate ATBC and dimethylolpropionic acid contents are critical to formation of stable translucent dispersion of the WPU with total hard segments as high as 56 wt% at –NCO/-OH molar ratio of 1.05. Molecular structure and ATBC existence of the WPU film have been characterized by IR, NMR, gas chromatography, and thermogravimetry, suggesting that ATBC will not release into the environment even if at 140 °C because of its high boiling point and ultralow volatility. The reserved ATBC in the WPU film also acts as an effective plasticizer and lubricant so that the WPU film can be quickly peeled off from PET. The lowest T-peel strength of 1.3 N m−1 on PET is achieved for the WPU film with a high tensile strength of 15.8 MPa and a medium elongation at break of 237%. The WPU films have tunable stickiness onto PET film from sticky to completely nonsticky. Importantly, the WPU films offer simultaneously strong adhesion to Al nanofilm and high thermal stability but high peelability from the PET, allowing to fabricate a stable holographic/photolithographic composite film by Al deposition at >1000 °C and ensure high flatness and luster of the composite film. Optimal formulations of WPU materials with high comprehensive performance including good film-processability, ultralow VOC emission, high mechanical and thermal properties, controllable surface tension, and tunable adhesion to Al nanofilm have been proposed for transferable holographic films.

Effect of DMPA Content on Colloidal Stability of Jatropha Oil-based waterborne Polyurethane Dispersion

Driven by the increase of oil price in the market as well as environmental concerns by the society, a renewable raw material such as vegetable oil becomes the alternative to produce bio-based polyol to replace non-renewable polyols in polyurethane production. The recent development of aqueous polyurethane dispersion proves that environmentally waterborne PUD offers an efficient alternative to the solvent-borne PUD for the application in ink, adhesives, and coatings. In this study, the jatropha oil has been successfully functionalized to polyol (JOL) by epoxidation and oxirane ring opening steps. Jatropha oil-based waterborne polyurethane (JPU) dispersions were produced by polymerizing the JOL with isophorone diisocyanate (IPDI) and dimethylolpropionic acid (DMPA). The colloidal stability of JPU dispersions was studied in terms of particle size and zeta potential. Varying DMPA content from 5.0-7.0 wt.% resulted in small average particle size of dispersion from 39.40 nm to 133.2 nm. High zeta potential obtained in a range of -52 mV to -65 mV indicates the particles in the dispersion are sufficiently separated and therefore stable. Eventually, the study provides an overview of vegetable oil-based waterborne polyurethane dispersion with good stability for surface coating application.

Preparation and research of waterborne polyurethane phase change material

ABSTRACTThis paper first designed the molecular structure of the water-soluble polyurethane phase change material. Taking HDI (hexamethylene diisocyanate), PEG (polyethylene glycol), chain extender (DMPA (dimethylolpropionic acid), BDO (1,4- butanediol), EDA (ethylenediamine)), catalyst (DBTDL (February acid dibutyl tin)), neutralizing agent (TEA (triethylamine)) as the raw material, the paper then prepared the waterborne polyurethane phase change material, which is available for wet spinning process. The particle size, appearance, storage stability, water absorption, tensile strength and elongation at break of the WPUPCM emulsion were then tested. Moreover, the influences of reaction temperature, reaction time, R value (ie -NCO / -OH molar ratio), PEG relative molecular mass and DMPA content on the WPUPCM performance indicators were investigated. The study indicated that reaction temperature, reaction time, R value, PEG relative molecular mass and DMPA content show various influences on WPUPCM performance indicators. Therefore, in order to meet the requirements of practical application and determine optimal formulation and process parameters, further relevent studies based on comprehensive considerations of all factors are needed.

Preparation and properties of emulsifier-/NMP-free crosslinkable waterborne polyurethane-acrylic hybrid emulsions for footwear adhesives (II) – effect of dimethylol propionic acid (DMPA)/pentaerylthritol triacrylate (PETA) content

AbstractStable emulsions (solid content: 38%) of emulsifier-/N-methylpyrrolidone (NMP)-free crosslinkable waterborne polyurethane-acrylic hybrids with a fixed acrylic monomer content (20 wt.%) and different molar ratios (mole%) of dimethylol propionic acid (DMPA)/crosslinkable pentaerythritol triacrylate (PETA)(17/23, 22/17, 27/11, 32/5) were successfully prepared. This study examined the effect of mole% of DMPA/PETA on the stability and viscosity of hybrid emulsions, the tensile properties/dynamic mechanical thermal properties of hybrid film samples and the adhesive strengths of formulated adhesives for footwear at both dry and wet states. The tensile strength/modulus, storage modulus and Tgs increased with increasing PETA content. The adhesive strength at dry state increased with increasing DMPA content up to 27 mole%, and then decreased a little. However, the adhesive strength at wet state decreased with increasing DMPA content. The optimum DMPA/PETA contents were found to be 27/11 mole% to achieve high performance adhesive properties.

Synthesis and characterization of waterborne polyurethane emulsions based on poly(butylene itaconate) ester

Waterborne polyurethane (WPU) prepolymer was synthesised by the reaction of poly(butylene itaconate) ester (PBI, Mn = 1109 g/mol), 1,6-hexanediol, dimethylol propionic acid (DMPA), 2,4-toluene diisocynate (TDI), hydroxyethyl acrylate (HEA), and absolute ethanol as blocking agent, triethylamine as neutralizer. Cross-linked WPU was synthesized by trimethylolpropane (TMP) as crosslinker. The influences of PBI, DMPA, and TMP content on WPU emulsions and films were investigated. The structure of WPU was determined by Fourier transform infrared (FTIR) spectra, thermal properties and glass transition temperature of WPU films were determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively, and morphology of the emulsion particles was observed by transmission electron microscopy (TEM). Through TGA, the heat resistance of the cross-linked WPU film was better than WPU film. By DSC analysis, glass transition temperature of cross-linked WPU film (21 °C) was higher than WPU film (10 °C).

Biocompatible, Biodegradable, and Electroactive Polyurethane-Urea Elastomers with Tunable Hydrophilicity for Skeletal Muscle Tissue Engineering

It remains a challenge to develop electroactive and elastic biomaterials to mimic the elasticity of soft tissue and to regulate the cell behavior during tissue regeneration. We designed and synthesized a series of novel electroactive and biodegradable polyurethane-urea (PUU) copolymers with elastomeric property by combining the properties of polyurethanes and conducting polymers. The electroactive PUU copolymers were synthesized from amine capped aniline trimer (ACAT), dimethylol propionic acid (DMPA), polylactide, and hexamethylene diisocyanate. The electroactivity of the PUU copolymers were studied by UV-vis spectroscopy and cyclic voltammetry. Elasticity and Young's modulus were tailored by the polylactide segment length and ACAT content. Hydrophilicity of the copolymer films was tuned by changing DMPA content and doping of the copolymer. Cytotoxicity of the PUU copolymers was evaluated by mouse C2C12 myoblast cells. The myogenic differentiation of C2C12 myoblasts on copolymer films was also studied by analyzing the morphology of myotubes and relative gene expression during myogenic differentiation. The chemical structure, thermal properties, surface morphology, and processability of the PUU copolymers were characterized by NMR, FT-IR, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and solubility testing, respectively. Those biodegradable electroactive elastic PUU copolymers are promising materials for repair of soft tissues such as skeletal muscle, cardiac muscle, and nerve.

Waterborne polyurethane dispersions synthesized from jatropha oil

A series of waterborne polyurethane dispersions derived from jatropha oil-based polyol (JOL) with different OH numbers ranging from 138 to 217mgKOH/g, were successfully prepared. Jatropha oil-based polyols were synthesized by epoxidation and oxirane ring opening using methanol. The JOLs produced were then used to prepare jatropha oil based waterborne polyurethane (JPU) dispersions by reaction with isophrene diisocyanate (IPDI). Dimethylol propionic acid (DMPA) was used as an internal emulsifier to enable the dispersion of polyurethane in water. The influence of the OH number, DMPA content and hard segment content on the stability of the wet JPU dispersions, as well as the physical, mechanical and thermal properties of the dry JPU films were investigated. The results reveal that with increasing OH number, the DMPA content and hard segment content significantly decrease the particle size from 1.1μm to 53nm, indicating increasing stability of the dispersions. JPU films exhibit the stress–strain behavior of an elastomeric polymer with a Young's modulus ranging from 1 to 28MPa, a tensile strength of 1.8 to 4.0MPa and elongation at break ranging from 85 to 325%. The polyurethane dispersions synthesized in this work possess good pendulum hardness, water repellence and thermal stability with promising application as a binder for wood and decorative coatings.

Property profile of poly(urethane urea) dispersions containing dimer fatty acid-, sugar- and amino acid-based building blocks

The understanding of the polymer composition–properties relationship is of great importance to improve the mechanical properties of bio-based polyurethanes containing long chain fatty acid derivatives. In this work, water-borne poly(urethane urea) dispersions containing dimer fatty acid-based diisocyanate (DDI), ethyl ester l-lysine diisocyanate (EELDI), 1,4:3,6-dianhydro-d-glucitol (isosorbide, IS) and dimethylolpropionic acid (DMPA) residues were prepared. The investigation focuses on the thermal and mechanical properties of these dispersion-cast films as well as on the morphology in correlation with the polymer composition. Significant dependencies of these properties and the morphology on the polymer composition are observed. By partially replacing the flexible DDI with the rigid EELDI as well as by increasing the isosorbide contents in the monomer feed, the Tg as measured by DSC was significantly enhanced from 18 to 58°C (1st Tg) and to above 70°C (2nd Tg). As evidenced from the DSC, AFM and FT-IR measurements, the H-bonds-induced micro-phase separation was influenced by the polymer composition. The observed improved phase mixing at relatively high EELDI-to-DDI ratio was related to the increased EELDI content and the corresponding urethane/urea bonds. The viscoelastic behavior of these dispersion-cast films showed a strong dependence on the ratio of the flexible DDI to the rigid EELDI and were less dependent on the IS and DMPA contents.

Properties and paper sizing application of waterborne polyurethane emulsions synthesized with isophorone diisocyanate

In this work, a two-step synthesis methodology has been used to synthesize a series of waterborne polyurethane (WPU) emulsions with isophorone diisocyanate (IPDI), poly-caprolactone diol (PCL) and dimethylol propionic acid (DMPA) as monomers and ethylenediamine (EDA) as the chain extender, respectively. The influences of the NCO/OH molar ratio, DMPA content, chemicals-adding sequence, and acetone content on the physical properties of the resultant emulsions have been investigated in detail. The results show that the emulsion viscosity increases with an increase in the NCO/OH molar ratio or DMPA content whereas it declines sharply as the acetone amount increases. The emulsion particle size is seen to increase with the NCO/OH molar ratio but it decreases as the DMPA content increases. The chemicals-adding sequence is observed to strongly affect the particle size and viscosity of the resultant emulsions. For cast films, with an increase in the NCO/OH molar ratio, the elongation monotonically decreases while the tensile strength is seen to increase at first and then deceases. The film water absorption capacity is found to go up as the DMPA content increases. Furthermore, after sized with the emulsions, the paper water resistance is markedly improved and the 30s Cobb value is seen to decrease by 63% as compared to the unsized counterpart. The paper folding resistance and the tensile index are also improved to certain extents. For producing well-performed WPU emulsions for sizing paper sheets, an NCO/OH molar ratio of 1.6–1.8 and a DMPA content of 6.0–7.0 wt.% are preferably chosen.

Reactivity and Regio-Selectivity of Renewable Building Blocks for the Synthesis of Water-Dispersible Polyurethane Prepolymers

To prepare water-borne polyurethane dispersions (PUD) from novel, renewable-based, asymmetric, bifunctional building blocks, it is important to understand the reactivity and regio-selectivity differences between the various functional groups and reagents, respectively. This paper first describes the mutual reactivity and regio-selectivity of biomass-derived asymmetric 1,4:3,6-dianhydro-d-glucitol (isosorbide, IS) and ethyl ester l-lysine diisocyanate (EELDI) in polyurethane (PU) syntheses. The regio-selectivities of the endo- and exo-OH functional groups of IS and the primary ε-NCO and secondary α-NCO of EELDI were found to have only minor consequences for the formation of NCO-terminated PU prepolymers. In addition, a model study of IS, dimethylolpropionic acid (DMPA), EELDI, and a dimer fatty acid-based diisocyanate (DDI) in their respective PU reactions revealed the reaction rate differences between these four compounds. Surprisingly, a comparatively low reaction rate of DMPA was observed. For the PU prepolymers synthesized from the four mentioned components, an enrichment in DMPA near the polymer chain ends may thus be expected. Finally, PU dispersions prepared from these four-component prepolymers showed a good storage stability. The relatively small particle size at a low DMPA content and a high EELDI and IS content is predominantly regarded as the result of the hydrophilicity of EELDI, IS, and possibly the enhanced DMPA concentration near the chain ends of the PU prepolymer.

Properties and paper sizing application of waterborne polyurethane emulsions synthesized with TDI and IPDI

Waterborne polyurethane (WPU), used as surface-sizing agents, has received increasing concerns in the papermaking industry. In this work, using two-step synthesis techniques of pre-polymerization and chain-extending reaction, a series of new self-emulsifying WPUs have been obtained with toluene diisocyanates (TDI) and isophorone diisocyanate (IPDI) as the monomers, dimethylol-propionic acid (DMPA) as hydrophilic chain extender. The influences of the NCO/OH molar ratio, DMPA contents, and TDI/IPDI molar ratio on the physical properties of the resultant emulsions have been investigated in detail using various characterization methods. Furthermore, the emulsions synthesized have been used for paper surface sizing applications. After sized, the paper water resistance along with other properties has been improved greatly as compared with the unsized counterparts. In view of the paper sizing effect, well-performed WPUs may be synthesized with NCO/OH molar ratio of 1.6–1.8, DMPA of 5.0–7.0% and TDI/IPDI molar ratio of 5:1.

Novel polyurethane dispersions based on renewable raw materials—Stability studies by variations of DMPA content and degree of neutralisation

Renewable resources, especially natural oils, have received increasing attention as raw materials for polymers. The synthesis and characterisation of novel aqueous polyurethane dispersions derived from rapeseed oil are investigated. The applied renewable polyol is high-hydrophobic due to the triglyceride backbone. Dimethylolpropionic acid (DMPA) as internal emulsifier was used to incorporate hydrophilic groups into the polymer chain to achieve stable self-emulsifying dispersions. By neutralisation of the carboxyl groups with triethylamine a predominately electrostatic stabilisation was generated. A weak steric stabilisation by pending chain ends exists beside the predominant electrostatic stabilisation. Outgoing from a DMPA content of 5.6wt% related to the polymer, the content was decreased successively with the objective being to analyse the influence of ionic concentration and stability. Furthermore, the influence of the degree of neutralisation with respect to the stabilisation of these novel dispersions was investigated.

The waterborne polyurethane dispersions based on polycarbonate diol: Effect of ionic content

Three water-based polyurethane dispersions (PUD) were synthesized by modified dispersing procedure using polycarbonate diol (PCD), isophorone diisocyanate (IPDI), dimethylolpropionic acid (DMPA), triethylamine (TEA) and ethylenediamine (EDA). The ionic group content in the polyurethane-ionomer structure was varied by changing the amount of the internal emulsifier, DMPA (4.5, 7.5 and 10 wt.% to the prepolymer weight). The expected structures of obtained materials were confirmed by FTIR spectroscopy. The effect of the DMPA content on the thermal properties of polyurethane films was measured by TGA, DTA, DSC and DMTA methods. Increased DMPA amounts result in the higher hard segment contents and in the increase of the weight loss corresponding to the degradation of the hard segments. The reduction of hard segment content led to the elevated temperature of decomposition and to the decrease of the glass transition temperature and thermoplasticity. The atomic force microscopy (AFM), results indicated that phase separation between hard and soft segment of PUD with higher DMPA content is more significant than of PUD with lower DMPA content. The physico-mechanical properties, such as hardness, adhesion test and gloss of the dried films were also determined considering the effect of DMPA content on coating properties.

Surface graft polymerization of conducting polyaniline on waterborne poyurethane‐urea film and its phenol sensing

AbstractWaterborne polyurethane‐ureas (pristine WBPUs: WBPU‐19 and WBPU‐24, fixed soft segment content: 60 wt %) containing dimethylol propionic acid (DMPA)/ethylene diamine (EDA) contents (19/16.8 and 24/11.4 mol %) were prepared. The polyaniline (PANI)‐graft‐WBPU (PANI‐graft‐WBPU) films were prepared by oxidative graft polymerization of aniline on the surface layer of WBPU films. This study focused on the effects of reaction conditions (concentrations/treating times/temperatures of aniline and APS) and DMPA content on the %grafting, conductivity, and mechanical properties of PANI‐graft‐WBPU films. To obtain the maximum %grafting (PANI‐graft‐WBPU‐19: 6.2, and PANI‐graft‐WBPU‐24: 7.4) and conductivity (PANI‐graft‐WBPU‐19: 3.6 × 10−2S/cm, and PANI‐graft‐WBPU‐24: 4.7 × 10−2S/cm), the optimum concentrations/treating times/temperatures of aniline and APS, were found to be 0.35M/10 min/25°C and 0.2M/10 min/0°C, respectively. The tensile strength of film samples was found to be increased in the order of PANI‐graft‐WBPU‐19>pristine WBPU‐19>PANI‐graft‐WBPU‐24>pristine WBPU‐24. The PANI‐graft‐WBPU‐19 (%grafting: 6.2) films on exposure to 0–10,000 ppm phenol solutions showed a well‐defined response behavior, demonstrating high promise for application in aqueous phenol sensors. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Waterborne polyurethane/poly(n-butyl acrylate-styrene) hybrid emulsions: Particle formation, film properties, and application

In this work, a hybrid synthesis technology has been used to fabricate waterborne polyurethane (WPU)/poly(n-butyl acrylate-styrene) (PBS) emulsions with dimethylol-propionic acid (DMPA) as chain extender. The influences of the PBS, styrene, and DMPA contents on the physical properties of the resultant emulsions and cast films have been investigated in detail using various characterization methods. The experimental results show that with an increase in the PBS or styrene content, the particle size in emulsions increases but the viscosity of the emulsions decreases and that the opposite applies for the DMPA content. For cast films, with an increase in the styrene or DMPA content, the tensile strength increases whereas the elongation decreases. The water absorption capacity of the film decreases with an increase in the styrene content or a decrease in the DMPA content. Furthermore, the emulsions synthesized have been used for paper sizing applications. The treated papers exhibit greatly improved water resistance, and the Cobb values at 30 and 60s are only 10.23 and 11.89%, respectively, of those of unsized papers. The other paper properties, such as gloss, smoothness, folding resistance, and burst strength, are also considerably improved.

Synthesis and Characterization of Anionic Polyester-Polyurethane Dispersion as Environmentally-Friendly Waterbased Resins

Aqueous polyurethane dispersions (PUDs) have recently emerged as important alternatives to their solvent-based counterparts for various applications due to increasing health and environmental awareness (green chemistry). Anionic polyester-polyurethane dispersions were synthesized by three steps. In the first step, macromonomer diisocyanate having carboxylic acid was prepared by isophorone diisocyanate (IPDI), dimethylol propionic acid (DMPA) in percent of acetone as solvent and dibutyldtin dilaurate (DBTDL) as catalyst. Then, carboxylic polyurethane was prepared by reaction macromonomer diisocyanate having carboxylic acid with linear aliphatic polyester (Mw=2000), trifunctional polyester (Mw=2800) and butanediol (BDO) as chain extender. The next step involved neutralization and dispersion in water, where acidic polyurethane was neutralized by the addition of triethylamine (TEA). Factors influencing the synthesis of polyurethane dispersion mainly involve reaction temperature, reaction time, the concentration of catalyst, DMPA content and BDO content, were studied. The polymers have been characterized with DSC and FTIR.