Saturated Polyester Resins Research Articles

Modeling effective elastic and thermal conductivity of composite materials reinforced with plastic waste: Analytical and numerical approaches

AbstractThe properties of materials used in building are enhanced by adding nanoparticles for improve energy efficiency. The objective of this study is to offer both numerical and analytical modeling methods of the thermal conductivity and mechanical property of composite materials. Various mineral charges were employed to reinforce the organic matrices of saturated polyester resin (UPR) with calcium carbonate (CaCo3) and expanded perlite particles. The study employs the finite‐element software COMSOL to conduct a numerical investigation of thermal transport in an elementary cell. The purpose is to ascertain the thermal conductivity of composites and examine the impact of contact resistance and the volume fraction of nanoparticles on the effective thermal conductivity. The results indicate that the numerical model proposed is consistent with the Hashin‐Shtrikman analytical model and experimental measurements. In another hand, the mechanical property is computed based on Mori‐tanaka analytical model of homogenization and finite element method by Digimat‐MF/FE, which gives enhanced elastic behavior of composite in function of volume fraction of nanoparticles, with high Young modulus and low Poisson ratio. The results indicate the performance of nanoparticles in improving thermomechanical behavior of building materials, and also in other applications.

Acid number, viscosity and end-point detection in a multiphase high temperature polymerisation process using an online miniaturised MEMS Fabry-Pérot interferometer

Recent advances in the latest generation of MEMS (micro-electro-mechanical system) Fabry-Pérot interferometers (FPI) for near infrared (NIR) wavelengths has led to the development of ultra-fast and low cost NIR sensors with potential to be used by the process industry. One of these miniaturised sensors operating from 1350 to 1650 nm, was integrated into a software platform to monitor a multiphase solid-gas-liquid process, for the production of saturated polyester resins. Twelve batches were run in a 2 L reactor mimicking industrial conditions (24 h process, with temperatures ranging from 220 to 240 °C), using an immersion NIR transmission probe. Because of the multiphase nature of the reaction, strong interference produced by process disturbances such as temperature variations and the presence of solid particles and bubbles in the online spectra required robust pre-processing algorithms and a good long-term stability of the probe. These allowed partial least squares (PLS) regression models to be built for the key analytical parameters acid number and viscosity. In parallel, spectra were also used to build an end-point detection model based on principal component analysis (PCA) for multivariate statistical process control (MSPC). The novel MEMS-FPI sensor combined with robust chemometric analysis proved to be a suitable and affordable alternative for online process monitoring, contributing to sustainability in the process industry.

Preparation and film formation mechanism of an environmental‐friendly polyester/epoxy ester coil coating primer

AbstractIn this investigation, we have prepared an environmental‐friendly waterborne coil coating primer. Waterborne saturated polyester resin and waterborne epoxy ester resin were selected as the binder resins, and methylated melamine resin and waterborne blocked isocyanate were selected as crosslinking resins. ZnMoO4, Zn3(PO4)2, Zn3Al(PO4)3, and AlH2P3O10 were selected as the anti‐corrosion pigments, and modified nano‐TiO2 particles and other fillers were also employed to further enhance the primer performance. It was found that when polyester/epoxy ester equals to 7/3; binder resins/curing agent equals to 5/1; pigments/binder resin is in range of 1.4–1.6; additives of each is in amount of 0.5 wt.%–1.5 wt.%, the obtained primer has ideal properties, such as T‐bend performance and qualified adhesion, and the salt spray resistance test can reach 360 h with the primer film thickness in range of 6 μm–7 μm after baking at 224 °C for 45 s. As to the coil coating primer film formation mechanism, Fourier transform infrared spectrum analysis indicates that both the amino resin and blocked isocyanate may react with the binder resin, and such chemical reactions can make them crosslinked to form a stereo‐network film, giving birth to a good overall performance of the obtained primer.

Fully Automated Determination of Trimellitic Anhydride in Saturated Polyester Resins Using Programmed Temperature Vaporization-Large Volume Injection-Gas Chromatography Previous Aqueous Derivatization with Triethyloxonium Tetrafluoroborate

Trimellitic anhydride (TMAn) is an essential starting material of the chemical manufacturing industry; it is widely used in saturated polyester resins (SPR) manufacturing to produce plasticizers for different purposes. TMAn was recently added, as a new substance of very high concern, to the candidate list by the European Chemicals Agency, since it can lead to sensitization, respiratory tract irritation and lung disease. Any substance from the list of candidates if present in manufactured products at concentrations above 0.1% (w/w) obliges the manufacturer to communicate this to customers down the supply chain and to consumers. We propose here a method that allows the fully automated determination of TMAn in SPR samples by using large volume injection (LVI), with programmed temperature vaporization (PTV) injection, in a gas chromatographic (GC) system equipped with ion trap mass spectrometer (IT) operating in tandem mass spectrometry (MS/MS). The method optimization was obtained by a chemometric model, using the experimental design. Introducing the use of short chromatographic column, triethyloxonium tetrafluoroborate (TEO) as derivatization agent and IS granted specificity, sensitivity and robustness. The detection and quantification limits for TMAn were 0.01% and 0.03% w/w, respectively. Trueness (between 94 and 98%) and precision (RSD lower than 10%, n = 6) were also assessed.

Biochar From Sugarcane Waste In Polymer Matrix Composite

The present work focuses on development of new type composite using bio char as reinforcement. The bio char is derived from sugarcane waste when undergo pyrolysis process. Because of the growing demand for waste utilization development of bio char from such wastes proves to be a potential one for various applications. In this study focuses bio char reinforced saturated polyester resin for composite fabrication. The composites are prepared by solution dispersion method. Bio char of different weight percentages such as 5, 10 and 15% were reinforced polyester matrix for taken this study. The prepared specimens are subjected to tensile strength, flexural strength, hardness and impact strength.

Synthesis, Characterization and Biological Activity of Iron (III) Oxide and Titanium (IV) Oxide Nanoparticle Dispersed Polyester Resin Nanocomposites

In this work, dispersed nanoparticles of Fe2O3- and TiO2-reinforced linear saturated polyester resin nanocomposites were fabricated. Nanosized oxides of iron (III) and titanium (IV) and polyester resin were prepared throughout sol–gel deposition and polycondensation reactions, respectively. The incorporation of nanostructured metal oxides with polyester matrix was characterized. Molecular weight, structure, composition, morphology and electric property of composites were investigated by gel permeation chromatography, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and conductivity measurements. The obtained nanocomposites exhibit low crystallinity, high agglomeration and high conductivity due to the ionic cross-linking. Moreover, the biological activity of the fabricated nanocomposites was studied against selected strains of pathogenic bacteria and fungi. The biological effect of polyester nanocomposites has higher value than the free one. These nanocomposites will find potential sites in catalysis.

Soundproofing flexible polyurethane foams: Effect of chemical structure of chain extenders on micro-phase separation and acoustic damping

In this study, a new high-performance acoustic damping flexible polyurethane foam (FPUF) was successfully designed and fabricated using synthesized linear saturated aliphatic polyester resin as polyol, methylene diphenyl diisocyanate, and ethylene glycol, monoethanolamine, and ethylenediamine as chain extenders and other reagents by one-shot bulk polymerization (isocyanate index = 100 and water content = 2.5%). The effect of the chemical structure of different chain extenders on micro-phase separation and acoustic damping properties of FPUFs were investigated using comprehensive characterization techniques such as atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FT-IR), compressive strength, optical microscope, and‏ ‏impedance tube. It was indicated that the micro-phase separation degree of the FPUF matrix increased with increasing amine content in the chain extender structure due to the more bidentate hydrogen bondings formation between urea-urea groups. Also, by increasing micro-phase separation, average cell sizes decreased and compressive strength, open-cell contents%, cell walls roughness, and cell size distribution of FPUFs increased. According to the sound absorption spectra, it was found that sound absorption efficiency of FPUF containing DEA was higher than FPUF manufactured by EG by 13.23% in the range of 1500–4000 Hz due to the increase of the amine content of chain extenders. These results indicate that the acoustic properties of FPUFs can be explained with the synergistic actions of micro-phase separation including the viscoelastic behavior of hard-soft segments and increasing of airflow pathway leading to dissipating of the kinetic energy of sound waves. Finally, the results revealed that soundproofing FPUFs with an optimum condition for micro-phase separation and drainage flow can be a promising candidate for using as sound insulating materials in transportation industries such as airplanes, trains, etc.

Global saturated polyester resin market to grow at a CAGR of 5.83% from 2016 to 2021: M&M

Global saturated polyester resin market to grow at a CAGR of 5.83% from 2016 to 2021: M&M

Layered double hydroxides as transesterification catalysts and nanofillers for polyester resin

Saturated polyester resins were prepared by reaction of dimethylterephthalate with alkylene glycols in the presence of layered doublehydroxides (hydrotalcites, HT). The effect of HT composition (cation and aniontypes) on the rate and progress of transesterification was investigated. It was found that zinc-aluminum HT intercalated with anionic form of aminolauric acid[HT(ZnAl)ALA] efficiently catalyzes transesterification process, increasing therate of reaction or lowering its temperature when compared to the reaction with use of conventional organic tin catalyst. The polyester resin obtained in this way is transparent, which along with X-ray diffraction data indicates the delamination of clay layers and formation of nanocomposite. The limitation of using ALA-intercalated HT as an additive for polyesters used in coatings is coloration of the resin with an increase of the reaction temperature above 180°C. Colorless polyester was obtained using more thermally stable hydrotalciteintercalated with ethylenediaminetetraacetic acid, however, at the expense of significantly longer reaction time. Using HT(ZnAl)ALA catalyst a two-step synthesis of carboxyl polyester resin was performed and the obtained product was used as a component of powder coating formulation.

Studing Some Effective Parameter on The Dielectric Properties of Composite Materials Containing of Un Saturated Polyester Resin

Studing Some Effective Parameter on The Dielectric Properties of Composite Materials Containing of Un Saturated Polyester Resin

Advances in high-field insulating polymeric materials over the past 50 years

The development of electrical insulation is closely associated with the development of electrical apparatus. Up to about 1925 only naturally occurring products such as asphalt, rubber, mica, cotton thread or fabric were generally used. Mineral oil-impregnated paper was used in transformers, capacitors, and underground cables at voltages up to 69 kV [1]. Then the first synthetic insulating materials, namely phenolic (Bakelite®) and alkyd (saturated polyester) resins, were used in insulating varnishes. Polyvinylchloride was introduced in 1936 to replace natural rubber in underground cable and house wiring, but in spite of tremendous advances in compounding polyvinylchloride to improve its properties, the electrical losses could not be reduced sufficiently. It was restricted to LV applications up to a few kilovolts. A variety of synthetic elastomers was used to replace natural rubber for HV applications, e.g., butyl rubber in the 1940s and ethylene-propylene rubber later on. Epoxy and polyester resins became available around 1945 and were first used for molding and encapsulation of electronic components, then mostly in laminated form as electrical insulation for LV applications [2]. Increased knowledge of the chemistry of insulating materials, and improved processing, then led to the availability of a large number of plastic materials such as polyethylene terephthalate, polycarbonate, polystyrene, low- and high-density polyethylene, polypropylene, polytetrafluoroethylene and fluorinated ethylene-propylene copolymer, suitable in thin film form for capacitor applications. These thin films could work at high electrical stresses or, put more practically, at minimal dielectric thickness appropriate to the capacitor working voltage. Thin films (<;10 μm) of these materials have intrinsic electric strengths in the range 500 to 1,100 V/μm at room temperature, probably 2 to 10 times higher than the average breakdown strength of plastic-film capacitors at the time [3]. Polyethylene-insulated of electrical energy, a statement that is still valid today and certainly will remain valid in the future. The objective of this paper is to give an overview of the research carried out over the last 50 years that has contributed to the development of high-field polymer dielectric materials in a broad sense. During this time thermoplastic polymers have been used in a large variety of electrical systems, e.g., cables, capacitors, transformers, bushings, electrical machines, and accessories operating in a large variety of environments (space, nuclear, thermal, etc.). Progress has been highly nonlinear in time, entangled with progress in material sciences, our understanding of the electrical properties of insulating polymers, and advances in material processing. We emphasize what are, in our view, the main features.

Synthesis and characterization of saturated polyester and nanocomposites derived from glycolyzed PET waste with varied compositions

Saturated polyester resin, derived from the glycolysis of polyethyleneterephthalate (PET) was examined as an effective way for PET recycling. The glycolyzed PET (GPET) was reacted with the mixture of phthalic anhydride and ethylene glycol (EG) with varied compositions and their reaction kinetic were studied. During polyesterification of GPET, acid and EG, the parameters like degree of polymerization (DP n ), extent of reaction (p) acid value and hydroxyl values were measured. The thermomechanical properties and the morphologies of the saturated polyester nanocomposites were examined by using a differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), wide angle X-ray diffraction (WAXRD) and transmission electron spectroscopy (TEM). There were significant differences observed in \({T}_{\textrm{g}}\), \({T}_{\textrm{m}}\) and \({T}_{\textrm{c}}\) before and after addition of GPET and clay content. Nanocomposites with lower content of organoclay showed intercalated morphology while by increasing the amount of organoclay, the exfoliated morphology was more prevalent. Water vapour transmission (WVT) was determined for saturated polyester nanocomposite sheets according to ASTM E96-80.

The durability of clear polyurethane coil coatings studied by FTIR peak fitting

A step scan phase modulation photo-acoustic (SS-PM-PA) Fourier transform infrared (FTIR) peak fitting method has been developed and applied to study (i) the degradation of the polyurethane (PU) coatings crosslinked with different isocyanates, (ii) the harshness of the natural exposure sites, and (iii) the correlation between the accelerated and natural exposure sites in terms of the degradation. Methyl ethyl ketoxime (MEKO) blocked hexamethylene diisocyanate biuret (HDI-BI), MEKO blocked hexamethylene diisocyanate cyclic trimer (HDI-CT) and 3,5-dimethyl pyrazole (DMP) blocked isophorone diisocyanate cyclic trimer (IPDI-CT) were used as-received to crosslink a cycloaliphatic saturated polyester resin binder. It was found that HDI-CT crosslinked PU coating is more durable compared to the HDI-BI. IPDI-CT crosslinked PU coating gives higher durability than the HDI-CT and the HDI-BI. The areas of deconvoluted peaks with Centre X (cm−1) = 1573, 1553 and 1535 (amide II, NH–CO) and Centre X (cm−1) = 1832, 1813, 1792 and 1770 (acid, anhydride, peracid) are used for degradation index calculation, due to their consistent decreasing and increasing trends, respectively, along with the degradation. It has been found that the natural weathering site in Kuala Lumpur, Malaysia (KL) is harsher than that at Vereeniging, South Africa (SA). The harshness of one year SA and KL natural weathering is comparable to 300 h–900 h of the QUV A exposure test. FTIR peak fitting method outperformed the integration method by giving a better correlation between the accelerated and natural weathering tests in terms of the degradation.

Solubility and diffusivity of CO 2 in carboxylated polyesters

The solubility of CO 2 in saturated polyester resins at different temperatures (306 and 343 K) and pressures (0.1–30 MPa) has been measured using a magnetic suspension balance. The solubility data were used for estimating the binary diffusion coefficients. The results show a good solubility of CO 2 in polymers, up to 0.64 g CO 2/g polymer. The diffusion coefficients of supercritical CO 2 in polymers have generally high values and are in the range from 0.156 × 10 −8 to 10.38 × 10 −8 cm 2/s. DSC and XRD analyses of the semi-crystalline polymer samples indicate that amorphous degree of polymers after exposure to CO 2 is increased. The observed structural effects are dependent on pressure, temperature and time of exposure to CO 2.

The role of chemical oxidation in combined chemical-physical and biological processes: experiences of industrial wastewater treatment

In this work, some experiences are described concerning the application of chemical oxidation in the treatment of industrial wastewaters in combination with other chemical-physical and/or biological processes. In the first case, two different wastewaters from saturated and unsaturated polyester resin production were considered. In a second case, optimal process conditions were assessed for the treatment of a wastewater deriving from polystyrene production. A third experience dealt with a comparison among different processes (flocculation, Fenton process, ozonisation, oxidation by means of ozone and hydrogen peroxide, oxidation by means of hydrogen peroxide and UV radiation), for the pretreatment of two industrial wastewaters (the first one being produced in a textile factory, the second one coming from detergent manufacturing). The evaluation of different processes was carried out by means of laboratory scale tests, considering treatment efficiency (organic substance removal, changes in wastewater biodegradability) and parameters (chemicals and energy consumption, sludge production) which play an important role in cost determination.

Epoxy esters as corrosion inhibitors for aluminium pigment

The hydrogen evolution caused by aluminium pigment in aqueous alkaline media is inhibited by several epoxy ester resins. At pH 8 less hydrogen is evolved than at pH 10. One particular epoxy ester resin (EPE b) is an excellent corrosion inhibitor especially at the high pH value of 10. An increase of epoxy ester addition results in a decreased hydrogen evolution, ie, an increase of corrosion inhibition. Corrosion inhibition of aluminium pigment by the epoxy ester EPE b is not significantly affected by the addition of paint resins, saturated polyester or melamine resin.

Cyclic oligomers in saturated polyesters

To get an in-depth understanding of the structure–property relationship in saturated polyester resins, the reactivity of various diols and diacids as well as reaction conditions were studied. Adipic acid (AA), phthalic anhydride (PA), isophthalic acid (IPA), terephthalic acid (TPA), 2-butyl-2-ethyl-1,3-propanediol (BEPD) and 2,2-dimethyl-1,3-propanediol (NPG) were addressed. It was found that in addition to linear oligomers with carboxyl and/or hydroxyl end groups cyclic oligomers were detected. Cyclic dimers of TPA and NPG are known to migrate to the coating surface causing “blooming”. The understanding of this phenomenon and the monomers capable of forming cyclic dimers are the subject of this study, where we combined molecular modeling and analytical characterization. The probability of the formation of macrocyclic structures was shown to decrease in the order: BEPD–PA>BEPD–AA≥BEPD–IPA>BEPD–TPA. The temperature dependence was found to be small.

Investigations into vinylogic addition reactions of modified polyester resins

Saturated polyester resins were modified with acetoacetate or N-substituted 3-aminocrotonate (enamine) groups. The modified vehicles were combined with unsaturated acrylates which are commercially available for radiation curing. The combinations undergo vinylogic addition reactions which were investigated by means of differential scanning calorimetry (DSC) and other techniques. For comparison, the curing properties of films on glass and steel surfaces were studied. The investigation of the Michael addition between acetoacetate modified resins and various acrylates showed that this reaction can occur in two steps, probably due to the reaction of the second CH-acidic H atom. However, conversion of acrylate groups and crosslinking density proved to be insufficient. Hence, the mechanical and chemical resistance properties were out of discussion for practical use in the field of coatings. Better results with respect to surface properties, crosslinking density, conversion of acrylate groups, and reaction enthalpy were found after further treatment of the acetoacetate modified polyester with amines. The results, however, were strongly affected both by the acrylate oligomer selected and by the amine used for the second modification step (i.e. by the individual alkyl substitution on the aminocrotonate group). Surprisingly, the n-butyl amine derivative gave higher reactivity or better surface properties, respectively even compared to the reaction product with ammonia (which totally failed) and to the methyl amine derivative.

The scope of pyrolysis methylation reactions

Simultaneous pyrolysis—alkylation—gas chromatography procedures have recently been reported. The method is applicable to macromolecular material amenable to hydrolysis and subsequent alkylation, particularly esters and phenolic compounds. This paper outlines some further developments in the application of this procedure to the examination of saturated polyester resins, complex esters in drug formulations and UV light stabilisers, phenol-for-maldehyde resins, fatty acid triglycerides, natural waxes, kerogen and proteins, indicating the wider potential for the method.

Coir Fibres II: Evaluation as a Reinforcement in Unsaturated Polyester Resin Composites

Hybrid laminates consisting of glass fiber mat, chopped bristle coir fibers and un saturated polyester resin matrix were fabricated. Effect of treatment of coir fibers with alkali and dichloro methyl vinyl silane on the mechanical properties of the laminates was investigated. The hybrid composites having 66% resin (w/w) and 19.7% chopped coir fiber (1cm long) showed 35% improvement in flexural strength and 70% in flexural modulus over the neat polyester resin sheets. Mechanical properties of laminates increased on increasing the coir fiber length up to 1 cm beyond which a decrease in strength was observed. Hybrid laminates fabricated from NaOH treated coir fibers had better mechanical properties than those fabricated from untreated coir fibers. A decrease in thermal conductivity was observed with increasing weight fraction of coir fibers.