Commercial Unsaturated Polyester Resin Research Articles

Synthesis, Characterization and Application of Biobased Unsaturated Polyester Resin Reinforced with Unmodified/Modified Biosilica Nanoparticles.

This paper presents sustainable technology for environmentally friendly composite production. Biobased unsaturated polyester resin (b-UPR), synthesized from waste polyethylene terephthalate (PET) glycosylate and renewable origin maleic anhydride (MAnh) and propylene glycol (PG), was reinforced with unmodified and vinyl-modified biosilica nanoparticles obtained from rice husk. The structural and morphological properties of the obtained particles, b-UPR, as well as composites, were characterized by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The study of the influence of biosilica modification on the mechanical properties of composites was supported by hardness modeling. Improvement of the tensile strength of the b-UPR-based composite at 2.5 wt.% addition of biosilica modified with vinyl silane, named "b-UPR/SiO2-V" composite, has been achieved with 88% increase. The thermal aging process applied to the b-UPR/SiO2-V composite, which simulates use over the product's lifetime, leads to the deterioration of composites that were used as fillers in commercial unsaturated polyester resin (c-UPR). The grinded artificially aged b-UPR composites were used as filler in c-UPR for the production of a table top layer with outstanding mechanical properties, i.e., impact resistance and microhardness, as well as fire resistance rated in the V-0 category according to the UL-94 test. Developing sustainable composites that are chemically synthesized from renewable sources is important from the aspect of preserving the environment and existing resources as well as the extending their life cycle.

Enhanced performance of a bio‐based diluent with both vinyl and epoxide groups for unsaturated polyester resin applications

AbstractStyrene has been widely used as a reactive diluent for a variety of commercial unsaturated polyester resins (UPRs), but suffered from high volatility. In this work, we developed a bio‐based reactive diluent, 4‐vinylguaiacol glycidyl ether (DE4VG), via an epoxidation of 4‐vinylguaiacol (4VG). Excellent miscibility and high reactivity of DE4VG were demonstrated by a series of copolymerization tests with an unsaturated polyester prepolymer (named PMSD) synthesized from maleic anhydride, 1,3‐dihydroxypropane and succinic acid. While, significant advantages in terms of viscosity and volatility were confirmed. Additionally, DE4VG provides both vinyl and epoxide groups and the epoxide groups were cured using 4,4‐diamino diphenylmethane (DDM) to participate the network formation of the cured PMSD/DE4VG/TBPB/DDM resin, resulting in high glass transition temperature (Tg, 195°C), residual carbon (45.5%), tensile strength (41.75 MPa), and the elongation at break (4.5%), which were all significantly surpassed the cured PMSD/St/TBPB, PMSD/St/TBPB/DDM, PMSD/DE4VG/TBPB resin. This work provided a successful demonstration to replace styrene with a bio‐based reactive diluent in UPR preparation, not only overcame the high volatility of styrene, but also enhanced material performances of the cured resin.

Study on Synthesis of Unsaturated Polyester Resin with Improved Characteristics and Application in Artificial Stones

The unsaturated polyester resin (UPR) used in artificial stones is a special grade, which should satisfy all technical requirements. To synthesize this UPR, the new temperature program has been established according to fuse balance polycondensation method at maximum temperature at 200oC. This temperature program showed high stability, safety, and good reproducibility. The UPR properties respond to all technical requirements. Experiment showed, the most important requirement is keeping molar ratio (-OH): (-COOH) = 1,1 : 1,0. The physico-mechanical properties of artificial stone, using synthezied UPR – PHX (Sample S1) and commercial UPR – SHCP (Sample S2) indicated that mechanical properties of S1 is higher than that of S2. FESEM images show that S1 and S2’s morphology have UPR matrix iniformly distributed in a inorganic filler without phase separation at interphase.

Phase distribution changes of neat unsaturated polyester resin and their effects on both thermal stability and dynamic‐mechanical properties

AbstractA relationship between phase distribution of a commercial unsaturated polyester resin (UPR) and both thermal stability and dynamical mechanical properties, measured by thermogravimetric analysis and dynamic‐mechanical analysis respectively, is observed. Changes in phase distributions are achieved varying UPR components miscibility by means of temperature. Morphologies of the internal surfaces are analyzed by atomic force microscopy showing that more homogeneous nanostructures with smaller nodules result in the increase of the storage modulus and glass transition temperature of the thermosetting UPR. Tan δ peaks show that the phase rich in UP and the phase rich in polystyrene tend to decrease their differences at higher curing temperatures. Changes in the curing mechanism and kinetics with curing temperature are verified by differential scanning calorimetry. A theoretical explanation of archived morphology is proposed using interaction parameter between UP and styrene showing that higher temperatures increased their miscibility.

The Application of an Indigenous Polymer for the Plastination of Teaching Anatomical and Biological Specimens

Plastination was fabricated in 1978 by Dr. Gunther Von Hagens at the University of Heidelberg,, Germany,which Kept for the good conservation of anatomical and biological material. The present goal was to utiliz acost- effective plastination polymers as compared to the standard S10 technique using silicone polymers. TheS10 is the original silicone polymer used for the preparation of plastinated specimens and whole dissectingbody.. Specimens were fixed in formalin 10%, dehydrated and decreasing in acetone, and at last,impregnated bylocal commercial unsaturated polyester resin and ultimately hardening at 50 °C temperature.The plastinated specimens were clean, durable ,odorless ,portable and non-toxic ,it can be kept for longdurations without any changes .The usage of widespread S10 silicon method is high costs so with the aidof using indigenous chemicals it is possible to produced low costs anatomical models for education and forstudying anatomy.

End-Cap Modified Unsaturated Polyesters With Low Styrene Emission

A benzyl end-cap-unsaturated polyester resin (BP-UPR) with low styrene emission was synthesized. The structure of BP-UPR was characterized by Fourier transform infrared (FT-IR) spectroscopy. According to gel permeation chromatography (GPC) measurement, the BP-UPR has a relative low molecular weight (Mn=1754) and narrow polydispersity of 1.68. The styrene content of BP-UPR is only 25.1%, 8.3% lower than that of a commercial unsaturated polyester resin (C-UPR) with similar viscosity. The styrene emission of BP-UPR and C-UPR was compared by Luong–Walewski method. At the gel point (17 minutes), the styrene emission of BP-UPR is only 38.9g/m2, 15.9% lower than that of C-UPR. After curing for 2 hours, the total styrene emission of BP-UPR is only 62.5 g/m2, which is 48.0% lower than that of C-UPR.

Synthesis and Characterization of Novel Star-Shaped Itaconic Acid Based Thermosetting Resins

A star-shaped thermoset resin was synthesized by direct condensation reaction of itaconic acid and glycerol (star-Ita.Gly). In order to decrease the viscosity of the resin, the carboxyl groups of the oligomers were reacted with ethanol (Tstar-Ita.Gly). Chemical structures of the resins were studied by 1H and 13C NMR and Fourier-transform infrared spectroscopy (FT-IR). The curing process was optimized by studying the residual exotherms during the curing process. Thermomechanical properties of the cured samples were studied by Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). Thermogravimetric analyses (TGA) were also carried out on both treated and pure resins to study the thermal stability of the cured samples. The viscosity of both resins were measured at different temperatures and different stress levels. Water adsorption tests were also carried out to check the water absorption properties of Tstar-Ita.Gly’s cured samples. The viscosity of the star-Ita.Gly was 154.9 Pa s at room temperature which dropped to 1.8 Pa s upon increasing the temperature to 70 °C. The viscosity of the Tstar-Ita.Gly resin was 0.35 Pa s at room temperature, and 0.04 Pa s at 70 °C. The glass temperature (Tg) of the alcohol-treated resin was 122 °C. Fully biobased content and inexpensive raw materials, biodegradability, very good thermomechanical and comparably very promising rheological properties and processability along with good thermal stability are of advantages of the synthesized resin which make the resin comparable with other thermosetting systems as well as the commercial unsaturated polyester resins.

Synthesis and characterization of methacrylated star‐shaped poly(lactic acid) employing core molecules with different hydroxyl groups

ABSTRACTA set of novel bio‐based star‐shaped thermoset resins was synthesized via ring‐opening polymerization of lactide and employing different multi‐hydroxyl core molecules, including ethylene glycol, glycerol, and erythritol. The branches were end‐functionalized with methacrylic anhydride. The effect of the core molecule on the melt viscosity, the curing behavior of the thermosets and also, the thermomechanical properties of the cured resins were investigated. Resins were characterized by Fourier‐transform infrared spectroscopy, 13C‐NMR, and 1H‐NMR to confirm the chemical structure. Rheological analysis and differential scanning calorimetry analysis were performed to obtain the melt viscosity and the curing behavior of the studied star‐shaped resins. Thermomechanical properties of the cured resins were also measured by dynamic mechanical analysis. The erythritol‐based resin had superior thermomechanical properties compared to the other resins and also, lower melt viscosity compared to the glycerol‐based resin. These are of desired characteristics for a resin, intended to be used as a matrix for the structural composites. Thermomechanical properties of the cured resins were also compared to a commercial unsaturated polyester resin and the experimental results indicated that erythritol‐based resin with 82% bio‐based content has superior thermomechanical properties, compared to the commercial polyester resin. Results of this study indicated that although core molecule with higher number of hydroxyl groups results in resins with better thermomechanical properties, number of hydroxyl groups is not the only governing factor for average molecular weight and melt viscosity of the uncured S‐LA resins. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45341.

Effect of lactic acid chain length on thermomechanical properties of star‐LA‐xylitol resins and jute reinforced biocomposites

AbstractStar‐shaped bio‐based resins were synthesized by direct condensation of lactic acid (LA) with xylitol followed by end‐functionalizing of branches by methacrylic anhydride with three different LA chain lengths (3, 5 and 7). The thermomechanical and structural properties of the resins were characterized by 13C NMR, Fourier transform IR spectroscopy, rheometry, DSC, dynamic mechanical analysis (DMA), TGA and flexural and tensile tests. An evaluation of the effect of chain length on the synthesized resins showed that the resin with five LAs exhibited the most favorable thermomechanical properties. Also, the resin's glass transition temperature (103 °C) was substantially higher than that of the thermoplast PLA (ca 55 °C). The resin had low viscosity at its processing temperature (80 °C). The compatibility of the resin with natural fibers was investigated for biocomposite manufacturing. Finally, composites were produced from the n5‐resin (80 wt% fiber content) using jute fiber. The thermomechanical and morphological properties of the biocomposites were compared with jute‐PLA composites and a hybrid composite made of the impregnated jute fibers with n5 resin and PLA. SEM and DMA showed that the n5‐jute composites had better mechanical properties than the other composites produced. Inexpensive monomers, good thermomechanical properties and good processability of the n5 resin make the resin comparable with commercial unsaturated polyester resins. © 2017 Society of Chemical Industry

Synthesis, characterization and curing optimization of a biobased thermosetting resin from xylitol and lactic acid

A biobased thermoset resin was synthesized by direct condensation reaction of lactic acid with xylitol followed by the end-functionalization of the hydroxyl groups of branches by methacrylic anhydride. Chemical structures of resins were evaluated and confirmed by 13C NMR and Fourier-transform infrared spectroscopy (FT-IR). Different techniques were employed for the optimization of the curing process. Techniques including Microscopy, Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Thermal Analysis (DMTA) were employed for characterization of the cured resins. Thermogravimetric analyses (TGA) were also carried out to check the thermal stability of the cured resins. The viscosity of the neat resin was measured at different temperatures and different stress levels. Water adsorption tests were also carried out to check the water absorption properties of cured resins. The glass temperature (Tg) of the resin was 98°C, and the viscosity of the resin was 2.97Pas at room temperature which drops to 0.07Pas upon increasing the temperature to 85°C. The biobased content of the resin was calculated as 77%. Cheap raw materials, high biobased content, biodegradability, good thermomechanical and rheological properties, good processability and good thermal stability are of advantages of the synthesized resin which makes the resin comparable with commercial unsaturated polyester resins.

Interfacial properties of glass fiber/unsaturated polyester resin/poplar wood composites prepared with the prepreg/press process

Combining glass fiber-based composites to fast growing wood can remarkably enhance the mechanical properties of these wood materials, although it is really challenging to obtain an excellent adhesion between wood and commercial unsaturated polyester resin (UPR) composites even using structural adhesives. Herein, a Prepreg/Press process was investigated to prepare glass fiber/UPR/poplar wood composites by directly molding prepreg glass fiber onto the wood surface with the curing of the matrix. The effects of fabrication pressure and thickness gauge on the interfacial properties of composites were analyzed. To understand the formation of the wood/UPR interface, the wettability and penetrability between UPR and wood were evaluated, and the interface microstructure was observed with scanning electron microscopy. Results indicated that the Prepreg/Press process can achieve an interfacial adhesion between wood and glass fiber layer with the shear strength of up to 11.93 MPa. During a period of ten minutes, the contact angle of UPR onto wood significantly decreased from 103 ° to 33 °, and UPR had an absorptivity of 1.0×10−4 g/mm2 onto wood as high as water did. The favorable wettability and penetrability of UPR allowed it to penetrate into wood along the catheter and form a firm wood/UPR interface during the fabrication process.

Synthesis and characterization of unsaturated lactic acid based thermoset bio-resins

Bio-based thermoset resins have been synthesized using lactic acid oligomers, which were functionalized with carbon–carbon double bonds, in order to allow their crosslinking by a free radical mechanism. Two different resin structures were synthesized. One resin was composed of an allyl alcohol terminated lactic acid oligomer, which was end-functionalized with methacrylic anhydride (MLA resin). The second resin was a mixture of the same allyl alcohol-lactic acid oligomer, and penthaerythritol. This mixture was end-functionalized with methacrylic anhydride, in order to get a methacrylate functionalized lactic acid oligomer, and methacrylate functionalized penthaerythritol (PMLA resin). The synthesized resins were characterized using FT-IR, 1H NMR and 13C NMR spectroscopy, differential scanning calorimetry as well as dynamic mechanical analysis to confirm the resin structure and reactivity. The flow viscosities were also measured in order to evaluate the suitability of the resins to be used as a matrix in composite applications. The results showed that the PMLA resin has better mechanical, thermal and rheological properties than the MLA resin, and both had properties which were comparable with a commercial unsaturated polyester resin. The high biobased content of 90% and the high glass transition temperature at 100°C for the PMLA resin makes it an attractive candidate for composite applications where crude oil based unsaturated polyester resins are normally used.

Curing copolymerization kinetics of styrene with maleated castor oil glycerides obtained from biodiesel‐derived crude glycerol

ABSTRACTKinetics of curing of maleated castor oil glycerides with styrene was studied by differential scanning calorimetry and rheology. The resin was synthesized from biodiesel‐derived crude glycerol. Curing rates were fitted to several empirical models (autocatalytic model, Kamal's model and a model with vitrification). The three models showed a good fitting with experimental data at conversions lower than 0.55 for temperatures ranging from 30 to 50°C. However, the model that includes vitrification showed a better fitting in the entire range of conversions and the same temperatures. At higher temperatures (50–60°C), some deviations were observed for the three models at low and high conversions. Gel times were obtained from rheological studies and the apparent activation energies were calculated thereof. Gel times were 300–2700 s. The values of apparent activation energy obtained for this castor oil‐based copolymer (47.2–52.3 kJ/mol) were within range of commercial unsaturated polyester resins. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41344.

Synthesis and characterization of bio‐based thermosetting resins from lactic acid and glycerol

ABSTRACTA bio‐based thermoset resin has been synthesized from glycerol reacted with lactic acid oligomers of three different chain lengths (n): 3, 7, and 10. Lactic acid was first reacted with glycerol by direct condensation and the resulting branched molecule was then end‐functionalized with methacrylic anhydride. The resins were characterized by Fourier‐transform infrared spectroscopy (FT‐IR), by 13C‐NMR spectroscopy to confirm the chemical structure of the resin, and by differential scanning calorimetry and dynamic mechanical thermal analysis (DMTA) to obtain the thermal properties. The resin flow viscosities were also measured using a rheometer with different stress levels for each temperature used, as this is an important characteristic of resins that are intended to be used as a matrix in composite applications. The resin with a chain length of three had better mechanical, thermal, and rheological properties than the resins with chain lengths of seven and 10. Also, its bio‐based content of 78% and glass transition temperature of 97°C makes this resin comparable to commercial unsaturated polyester resins. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40488.

Interacting blends of Styrenated unsaturated poly (ester–amide)s with commercial unsaturated polyester resin (o-phthalic anhydride based)

Unsaturated poly (ester–amide)s resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol-A (DGEBA) and unsaturated aliphatic bisamic acids (B1–4) using a base catalyst. These UPEAs were then diluted by styrene and blended with commercial unsaturated polyester resin (o-phthalic anhydride based) to produce a homogeneous resin. The curing of these Styrenated UPEAs–UPR blends was carried out using Benzoyl peroxide (BPO) as a catalyst and N,N′-Dimethyl aniline (DMA) as a promoter. The glass fiber reinforced composites (i.e. laminates) of these Styrenated UPEAs–UPR (o-phthalic anhydride based) blends were fabricated. The mechanical and chemical resistance properties of the glass fiber composites have also been evaluated. The unreinforced cured samples of the Styrenated UPEAs–UPR (o-phthalic anhydride based) blends were also analyzed by thermogravimetry (TGA).

Porous functional poly(unsaturated polyester-co-glycidyl methacrylate-co-divinylbenzene) polyHIPE beads through w/o/w multiple emulsions: preparation, characterization and application

AbstractPoly(unsaturated polyester-co-glycidyl methacrylate-co-divinylbenzene) poly high internal phase emulsion (HIPE) beads were synthesized via water-in-oil-in-water (w/o/w) multiple emulsions. HIPEs were prepared by using a commercial unsaturated polyester resin (UPR) and a mixture of glycidyl methacrylate (GMA) and divinylbenzene (DVB) as the cross-linker. The external surfactant was found to be a strong influence on the morphology of the beads. The porosity and the pore morphology of the resulting polyHIPE beads were investigated by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) molecular adsorption method, respectively. Post-functionalization of the beads was carried out with multifunctional amines such as 1,4-ethylenediamine (EDA), 1,6-hexamethylenediamine (HMDA) and 4-aminosalicylic acid (ASA). Elemental analysis was used to confirm the functionalization. Resulting functional beads were tested on the adsorption of Ag(I), Cu(II), and Cr(III) under non-competitive conditions and atomic absorption spectroscopy (AAS) was used to calculate the adsorption capacities. The maximum adsorption capacities of the functional beads were found to be decreasing in the order of Ag(I)>Cu(II)>Cr(III).

Selección de resinas de poliéster insaturado para procesos de transferencia de resina en molde cerrado

En este artículo se analizan tres tipos de resinas poliéster in-saturado comerciales de amplio uso en el mercado nacional y se evalúa su conveniencia de uso en procesos de transferencia de resina en molde cerrado (RTM), de acuerdo con criterios de visco-sidad y reactividad. Se compara la viscosidad de las resinas entre 15 y 50°C, así como la reactividad mediante curvas de curado a temperatura ambiente, con porcentajes de catalizador del 1, 1.5 y 2%. De acuerdo con los resultados se determinó que algunas de las resinas son susceptibles de uso en procesos RTM, por su apropiada viscosidad, estabilidad en la reactividad y su velocidad de curado. Estas características son de gran importancia al momento de seleccionar las resinas poliéster insaturado, de acuerdo con las condiciones del proceso en molde cerrado.

Kompozyty handlowych nienasyconych zywic poliestrowych z dodatkiem nanonapelniaczy Nanobent

Kompozyty handlowych nienasyconych zywic poliestrowych z dodatkiem nanonapelniaczy Nanobent

A new type of unsaturated polyester resin with low dielectric constant and high thermostability: preparation and properties

A new type of unsaturated polyester resins (UP) with low dielectric constant (κ) and high thermostability was prepared by doping N-phenylmaleimides containing perfluoroalkyl substituents (–CF3 and –C6F13) into a commercial unsaturated polyester resin. In comparison with neat UP resin, the doped UP resins showed decreased dielectric constant and increased char yields. The best result was obtained when the substituent was –CF3, which gave a dielectric constant of 3.63 and 5 wt%, loss temperature of 336 °C with a char yield of 5.57% under N2. Such data are superior to those of neat UP resin, which showed dielectric constants of 4.38 and 5 wt%, a loss temperature of 327 °C with a char yield of 2.25% . In this contribution, a new environmentally-friendly procedure for the synthesis of the fluoro-containing maleimides was also provided, in which a Bronsted acidic room temperature ionic liquid was employed as a catalyst and the products were obtained through merely decanting and removal of the solvent.

Experimental Test Results from an Environmental Protection Agency Test Method for Determination of Vapor Suppressant Effectiveness

The results obtained from laboratory experiments conducted using Environmental Protection Agency (EPA) subpart WWWW of 40 Code of Federal Regulations (CFR) part 63 (1)-test method are discussed in this article. The original test method was developed to measure the effectiveness of wax suppressants used to reduce hazardous air pollutant (HAP) emissions from unsaturated polyester (UP)/vinyl ester resins. Wax additions of ∼1.5% by weight to commercial UP resins suppress HAP emissions through the formation of surface barrier films. However, the tests performed in this study included the use of limestone and an adjunct, organic fiber reinforcement, rather than the wax. The addition of either commercial product to the UP formulations tested in this study was also shown to reduce HAP emissions. Suppression was a combination of absorption and an increased diffusion path barrier for the volatile organic carbon (VOC) components. Based on the limited data obtained, it was shown that the oil absorption characteristics of the two adjunct products could be used to estimate the expected level of vapor suppression for a specific resin formulation. Values reported in the literature for the oil adsorption characteristics of the adjunct limestone and the commercial biomass fiber were used in the laboratory tests. Although the oil adsorption characteristic of any ingredient added to a base resin formulation is indicative of its potential for emissions reduction, the EPA test protocol is still required to be performed for validation. Such screening tests will always be needed due to the variability associated with commercial UP resins and the evolution of customized UP/fiberglass composite formulations developed by custom molding shops.