The effect of TiO2 nanopigment on the optical properties of polyester fabric in UV–VIS–NIR regions

The particle size parameter is a key factor that affects radiative properties of nanopigments, and consequently, pigments of the same type but different sizes represent different spectral performance. Therefore, current study dealt with a systematic experimental investigation on the effect of TiO₂ pigmented coatings on spectral reflectance and color performance of white and colored polyester fabrics in UV, VIS, and NIR region of electromagnetic spectrum, with a special emphasis on VIS region. In order to accomplish this target, polyester fabrics were coated with TiO₂ nanopigment with various concentrations and different diameters, and their reflectance spectra were measured using spectrophotometric method. Two‐way analysis of variance (ANOVA) was utilized to investigate the significance of the effect of TiO₂ nanopigment on the color performance of coated fabrics. According to experimental observations, an organized color shift appears in color coordinate of fabrics coated with TiO₂ nanopigment of various sizes. Moreover, although TiO₂ nanopigment with 35 nm diameter has the most significant impact on short wavelength region (UV region), the effect of pigment with 250 nm diameter is more noticeable on NIR region as long wavelength region.     

Stress–strain properties of polyurethane–polyacrylate interpenetrating polymer networks

Two-component interpenetrating polymer networks (IPN) of the SIN type (simultaneous interpenetrating networks) were prepared from two different polyurethanes (a polyester type and a polyether type) and a polyacrylate of two different crosslink densities. The linear polymers and prepolymers were combined in solution, together with crosslinking agents and catalysts, films cast, and subsequently chain extended and crosslinked in situ. In all cases, maxima in tensile strengths significantly higher than the tensile strengths of component networks occurred. This was explained by an increase in crosslink density due to interpenetration.     

Effect of xenon arc irradiation on optical whitened polyester woven fabrics

In this study, the CIE whiteness (CIE WI) and whiteness tint (T_w) of optically whitened (OWA) woven (plain and twill) polyester fabrics irradiated with xenon arc light were investigated. The fabrics were whitened in four concentrations using nine different commercial optical whitening agents, and were irradiated with xenon arc light under specific conditions between 0 and 100 h at 10‐h intervals. The reflectance of the OWA fabrics was measured by using spectrophotometer, whereas the CIE WI and T_w values were calculated by using computer software. The results were investigated by statistical methods using analysis of variance and regression curves in which of the CIE WI of OWA polyester fabrics was found to decrease, while the T_w was also affected depending on irradiation time from the xenon arc light. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2013     

The swelling behavior of interpenetrating polymer networks composed of polyurethane and unsaturated polyester

The kinetics of swelling and the sorption performance were observed for the polymer compositions with interpenetrating polymer networks made up of polyurethane and unsaturated polyester during their exposure to chlorobenzene at 25°C. It was found that the rates for solvent transport and solvent absorption processes were controlled by the chemical composition of the formulation studied. On the basis of the observed swelling process, parameters could be assessed which were specific for the mass transfer process, i.e., diffusion coefficient, sorption coefficient, and permeability coefficient. Moreover, an attempt was made to evaluate structural parameters that describe topology of the obtained networks. It was found that the increasing share of polyurethane in the composition reduced crosslinking density in the polyester network that resulted in faster diffusion of the solvent and higher sorption capacity for the solvent. The higher the styrene content in the composition, the higher the crosslinking density in the system, and hence the diffusion of solvent and its sorption inside the polymer network was much more difficult. In the scanning electron microscope analysis of samples, which had been subjected to swelling, no leaching was observed for any phase present in the system, despite phase separation for both the components. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3511–3519, 2006     

Stress–strain optical study of styrene–butadiene and ethylene–propylene rubbery copolymers

Birefringence–temperature behavior at constant stress during cooling and heating of styrene–butadiene and ethylene–propylene copolymers between ?120°C and +60°C was investigated. Copolymer composition, thermal treatment, and stress levels were shown to have a pronounced effect on the photoelastic properties.     

Thermally stable interpenetrating polymer networks for second‐order nonlinear optical materials

We report several kinds of interpenetrating polymer networks (IPNs) with nonlinear optical (NLO) properties. DMA spectra show that the two components of the IPNs have good compatibility with each other. The NLO materials have good optical transparency. The thermal stability of alignment was improved and the poled order remained very high. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 7–9, 1999     

Thermo gravimetric analysis and morphological behavior of castor oil based polyurethane–polyester nonwoven fabric composites

Castor oil (CO) based polyurethane (PU)– polyester nonwoven fabric composites were fabricated by impregnating the polyester nonwoven fabric in a reactive composition containing CO and diisocyanate. Composites were fabricated with two different isocyanates such as toluene‐2, 4‐diisocyanate (TDI) and hexamethylene diisocyanate (HMDI). Thermogravimetric analysis (TGA) studies of the composites were performed to establish the thermal stability and their mode of thermal degradation. It was found that degradation of neat PU takes place in two steps and that of polyester nonwoven fabric reinforced PU composites takes place in three steps. From the TGA thermograms, a little improvement in thermal stability incase of polyester nonwoven fabric reinforced PU composites were noticed compared to unreinforced PUs. Degradation kinetic parameters were obtained for the composites using Broido, Coats and Redfern, and Horowitz and Metzger methods. Tensile fractured composite specimens were used to analyze the morphology of the composites by scanning electron microscopic technique. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Fire behaviour of polyester–clay nanocomposites

The aim of this study was on the one hand, to compare the fire behaviour of polyester/clay nanocomposites with that of the neat polymers added with the conventional flame retardant melamine isocyanurate (MIC) and on the other hand, to study the effect of the flame retardant added to the nanocomposites. Polyester/clay nanocomposites were prepared by using polybutylene terephthalate (PBT) and a co‐polyester elastomer as polymeric matrices and a commercial organoclay as filler. As verified by X‐ray diffractometry (XRD) and transmission electron microscopy (TEM) intercalated structures were obtained by mixing the molten polymer with the layered silicate in a corotating twin screw extruder. The fire behaviour of these materials was investigated by means of an oxygen consumption calorimetry (Cone Calorimeter). Peak heat release rate of 3‐mm thick samples measured at 50 kW/m² external heat flux was reduced by a factor of 2–3 by the addition of organically modified montmorillonite to the polymers. The further addition of MIC did not give a significant improvement in the behaviour of the materials. Copyright © 2005 John Wiley & Sons, Ltd.     

Stress–strain properties and thermal resistance of polyurethane–polyepoxide interpenetrating polymer networks

Two-component interpenetrating polymer networks (IPN) of the SIN type (simultaneous interpenetrating networks) were prepared from three different polyurethanes and two epoxies. The linear prepolymers were combined in solution, together with crosslinking agents and catalysts, films cast, and subsequently chain extended and crosslinked in situ. Two of the IPN's showed significant improvement in thermal resistance, as measured by thermogravimetric analysis (TGA). All of the IPN's showed maxima in tensile strength significantly higher than the tensile strengths of the component networks at 25% polyurethane and minima at 75% polyurethane. The minima were explained by an initial dilution of the strong polyurethane hydrogen bonds by the epoxies, and the maxima, by an increase in crosslink density due to interpenetration.     

Polymaleamide–polymaleimide networks

Polymaleamide–polymaleimide networks were obtained as films by the thermal treatment of mixtures with different ratios of an aliphatic–aromatic polymaleamide (PMA) and 4,4′‐bis(maleimidodiphenylmethane) (BMI), in N‐methyl‐2‐pyrolidinone (NMP) as a solvent. The polymaleamides were synthesized by ring‐opening polyaddition of 1,6‐hexamethylene–bisisomaleimide with 4,4′‐diaminodiphenylmethane in NMP at room temperature. The networks are infusible and insoluble in organic solvents; therefore, they were studied by solid‐state techniques such as IR, DSC, thermooptical analysis (TOA), TG/DTG analysis, and TEM. Thermal treatment of pure PMA and BMI occurs with the formation of crosslinked structures as proved by IR spectra. DSC and TOA curves show the appearance of chemical interactions between PMA and BMI in cured films and the formation of ordered morphologies, especially when BMI is the major component. TG/DTG and TEM results supported these observations. The PMA–polymaleimide network films present electrical insulator properties superior to individual polyamides or polyimides. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 779–788, 2004     

Stress–strain behaviour of fire exposed self‐compacting glass concrete

Concrete normally suffers from low stiffness and poor strain capacity after exposure to high temperatures. This study focused on evaluating the effect of recycled glass (RG) on the residual mechanical properties of self‐compacting glass concrete (SCGC) after exposure to elevated temperatures. RG was used to replace fine aggregate at ratios of 0%, 25%, 50%, 75% and 100% by weight. The residual properties were evaluated according to compressive strength, elastic modulus, stress–strain behaviour and strain at pre‐load and peak stress. A comparative assessment of different curing conditions on the SCGC was also conducted. The results showed that there were significant decreases in compressive strength, elastic modulus and concrete stiffness of the concrete with increasing temperature. The use of RG had little influence on the elastic modulus at ambient temperature; however, after exposure to 800°C, the mechanical properties of the concrete were greatly enhanced by incorporating RG. Copyright © 2012 John Wiley & Sons, Ltd.     

Opto‐thermal properties of fibers: XVII. Structure characterization of cold drawn boiled viscose fibers

A two‐beam interferometric method is used to study the change of optical parameters of cold drawn boiled viscose fibers at different times. A stress–strain device conjugated to the Pluta polarizing interference microscope is used to investigate the dynamical behavior of opto‐mechanical properties at room temperature. Some structural parameters such as the number of molecules per unit volume, the virtual and isotropic refractive indices, the optical orientation factor and angle, the strain and the stress optical coefficients are evaluated. Some mechanical parameters such as, Young's modules, elastic shear modules and the compressibility are calculated over different strain values. Also the number of network chain per unit volume N_c, work per unit volume W, average work per chains W′, reduction in entropy ΔS, and the optical configuration parameter Δα are determined. Also calculation of the constants of Moony–Rivilin equation are given. A systematic study over different wavelengths range extending from 405 to 590 nm was carried out to obtain the dielectric constant at infinity. The obtained results clarify that new reorientations occurred due to cold drawing at different conditions. Empirical formula is suggested to correlate the change in Δn, f(θ), W, W′, A, θ, and N_c with different draw ratio, and its constants were determined. Microinterferograms and curves are given for illustrations. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1185–1201, 1999     

Evaluation of the mechanical properties of sisal–polyester composites as a function of the polyester matrix formulation

In this work a comparative study on the impact and tensile properties of polyester/sisal fiber reinforced composites was undertaken. The polyester matrix was used bare and modified with: (1) a silane coupling agent; (2) a flame retardant system; and (3) a blend of the silane agent and the flame retardant system. The experimental results show that the flame retardant acts as a particulate reinforcement to the polyester matrix and the silane coupling agent acts as a plasticizer. The simultaneous addition of these two compounds to the polyester resin tended to decrease the performance of the composites. The results obtained show that strength or toughness could be tailored, and although none of the composites manufactured with the modified polyester matrices showed a significant improvement on the fiber–matrix interface strength, a better compromise between impact and tensile properties was obtained with the silane modified matrix. The critical fiber volume fraction was also evaluated and shown to be less than 10% for the sisal–polyester composite investigated here. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1209–1217, 2004     

聚酯装置增容能力的分析探讨

介绍了仪征化纤 6万吨 /年聚酯装置 ,在不增加设备投入的前提下 ,仅通过对酯化段和缩聚段部分工艺参数的优化调整 ,从而达到提高装置产能的目的。并分析装置增容过程中出现的问题 ,提出解决方案 ,为同类装置的增容提供借鉴     

Fire behavior and smoke emission of phosphate–based inorganic fire‐retarded polyester resin

The fire behavior and the smoke emission of an unsaturated polyester resin modified by the addition of three phosphorus‐based fire‐retardant materials (ammonium polyphosphate (APP), silane‐coated APP, and melamine pyrophosphate) at two concentration levels (20% w/w, 35% w/w) have been investigated. Scanning electron microscopy, Fourier transform infrared spectroscopy and optical microscopy analysis have been performed to verify the dispersion and the action mechanism of additives within the resin. Results from cone calorimetric tests demonstrated that the incorporation of the fire retardants at 35% w/w has a strong effect on flammability and smoke suppressant properties with respect to both the neat resin and the loaded systems at 20% (w/w). In particular, the smoke formation and smoke parameters are reduced by 50% and 80%, respectively, leading to the conclusion that APP can be used single‐handedly without combination with specific smoke suppressors. Copyright © 2011 John Wiley & Sons, Ltd.     

Preparation of a novel alloy composed of fluorene‐based polyester and polycarbonate and their properties for the optical uses

This paper is concerned with the structures and properties for fluorene‐based polyester‐polycarbonate (FBP/PC) alloys. Obtained alloys were characterized thermodynamically, optically, and viscoelastically, and the relationship between drawing behavior and molecular dynamics were also investigated. FBP/PC alloys showed transparent and a single glass transition temperature (Tg) for all compositions that indicated the complete compatibility in FBP/PC alloy systems. Tendency of the maximum draw ratios for alloy sheets was very similar to the profile of Tg versus FBP content. Maximum draw ratio was increased linearly with FBP content, demonstrating the intimate relationship between the large deformation and the molecular motion. A large amount of orientational birefringence occurred in PC sheet, but in the case of FBP/PC alloys and FBP, orientational birefringence was drastically decreased or not observed at all. This meant that positive birefringence of PC molecules was compensated by the absolutely smaller birefringence of FBP molecules. From a molecular mobility perspective, relaxation time (T2) for PC was smaller even at 200°C. However, for FBP and its alloys, T2 were much larger, showing the considerably enhanced molecular mobility in FBP or FBP/PC alloys. In this study, we could first reveal that the relationship between Tg and FBP content was very similar to the behaviors of birefringence (Δn)/draw ratio (λ) versus FBP content, T2 versus FBP content and 1/maximum draw ratio (λ_max) versus FBP content. Based on these results, we were able to propose a novel alloy with high refractive index, low orientational birefringence, and higher processability by alloying FBP with PC. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Development of unsaturated polyester matrix – carbon nanofibers nanocomposites with improved electrical properties

In this work, the dispersion of carbon nanofibers (CNFs) in an unsaturated polyester (UP) resin was performed by mean of the calendering process. The calendering process allows to obtain good dispersion of the nanoparticles, and, with respect to the other techniques, is also possible to scale it up at the industrial level. Optimization of the calendering conditions for the processing was carried out as a first step of this study. Optimization, in this case, means to reach the best dispersion level, as rapidly as possible and with the lowest amount of styrene evaporation. The dispersion level reached was investigated by the technique of scanning electron microscopy. The investigation on electric conductivity of the nanocomposites at different CNF concentrations has revealed that the electrical percolation threshold exists at around 0.3 wt %, where electrical conductivity switches from 10^?13 to 10^?7 S/cm. The rheological characterization has been performed to verify if the improved electrical properties are obtained at the expense of loss of workability, that is a significant increase of viscosity. Eventually, a mechanical characterization was carried out. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Physicochemical characterization of the filler–matrix interface in elastomer‐encapsulated fly ash/polyester particulate composites

An attempt was made to improve the toughness of fly ash (FA)/general‐purpose unsaturated polyester resin (GPR) composites. Elastomer [styrene–butadiene rubber (SBR) or acrylic copolymer (AC)]‐encapsulated fillers (FA or CaCO₃) were made through the coagulation of the emulsified elastomer containing the filler with constant stirring. The elastomer‐encapsulated fillers were added to GPR at concentrations as high as 15 wt % to make FA/SBR or AC/GPR composites. The mechanical properties (i.e., the tensile strength, tensile modulus, tensile elongation, flexural strength, flexural modulus, impact strength, and hardness) of FA/GPR, FA/SBR/GPR, and FA/AC/GPR composites were studied. The tensile‐fractured surfaces of all the composites were studied with scanning electron microscopy. The thermal stability was studied with thermogravimetric analysis. An analysis of the results indicate that this modification technique is rather easy and more economical than the chemical modification of filler surfaces with functional silane coupling agents. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 171–184, 2005     

The effect of the morphology on the hygroelastic behaviour of polyester and epoxy resins

The effect of the morphology on the hygroelastic behaviour of polyester and epoxy resins is studied. The morphology is expressed by two factors, namely, the free volume of the polymer and a two-phase formation. The first factor is varied in styrene-crosslinked polyester using different styrene/alkyd proportions, and by using different immersion temperatures. The second is investigated in polyesters by replacing styrene with bromostyrene inducing a two-phase structure, and in epoxies by changing the hardener/epoxy ratio. It is shown that the hygroelastic response is affected markedly by the morphology. In general, both the moisture content and its rate of absorption are higher when the polymer network is more open and when more free volume is available. In some cases, however, the hygroelastic parameters are dominated by a two-phase structure where present.     

Synthesis and characterization of ZnS/hyperbranched polyester nanocomposite and its optical properties

The ZnS/hyperbranched polyester nanocomposite with higher refractive index was prepared by incorporating the acrylated 2-(2-mercapto-acetoxy)-ethyl ester-capped ZnS nanoparticles into the acrylated Boltorn™ H20 (H20). The acrylated 2-(2-mercapto-acetoxy)-ethyl ester-capped colloidal ZnS nanoparticles were synthesized by the reaction of zinc acetate with thioacetamide in N,N-dimethylformamide. The acrylated hyperbranched polyester was obtained by reacting acryloyl chloride with hydroxyl group of H20. The acrylated H20 plays an important role in stabilizing and dispersing ZnS nanoparticles with a diameter of 1-4 nm. The refractive indices of ZnS/hyperbranched polyester nanocomposites, depending on ZnS content, were determined to be in the ranges of 1.48-1.65.