Synthesis of unsaturated polyester resins based on rosin acrylic acid adduct for coating applications

Unsaturated polyester, UP, resins were obtained by reacting the propylene or ethylene glycol, PG or EG, with different acrylopimaric adducts APA, maleic anhydride as a source of double bond, phthalic anhydride and adibic acid as dibasic acids. The molecular weights of UP were determined by end group analysis. The chemical structures of the resulting UP resins were confirmed by ¹H NMR analysis. The curing exotherm of UP, vinyl ester resins (VE) and styrene was evaluated at temperatures from 35 to 55 °C using free radical initiator and accelerator. The curing behaviors of cured UP resins with styrene were evaluated by DSC measurements. The prepared UP curable resins were evaluated in the field of steel coating by measuring their mechanical properties and chemical resistance.     

Effects of chemical structure of polyurethane‐based low‐profile additives on the miscibility,curing behavior,volume shrinkage,glass transition temperatures,and mechanical properties for styrene/unsaturated polyester/low‐profile additive ternary systems. II: Glass transition temperatures and mechanical properties

The effects of three series of thermoplastic polyurethane‐based (PU) low‐profile additives (LPA) with different chemical structures and molecular weights on the glass transition temperatures and mechanical properties for thermoset polymer blends made from styrene (ST), unsaturated polyester (UP), and LPA have been investigated by an integrated approach of static phase characteristics‐cured sample morphology‐reaction conversion‐property measurements. The three series of PU used were made from 2,4‐tolylene di‐isocyanate (2,4‐TDI) and varied diols, namely polycaprolactone diol (PCL), poly(diethylene adipate) diol (PDEA), and poly(propylene glycol) diol (PPG), respectively, while the two UP resins employed were synthesized from maleic anhydride (MA) and 1,2‐propylene glycol (PG) with and without modification by phthalic anhydride (PA). Based on the Takayanagi mechanical models, factors that control the glass transition temperature in each phase region of cured samples, as identified by the method of thermally stimulated currents (TSC), and mechanical properties will be discussed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 558–568, 2000     

Synthesis and characterization of some novel unsaturated polyester resins containing amide groups

Summary An ethylenically dibasic acid amide was prepared by reacting anthranilic acid with maleic anhydride and characterized by various methods. The unsaturated dibasic acid amide was used for preparing three novel unsaturated polyesters with ethylene glycol (EG), diethylene glycol (DG) and tetraethylene glycol (TG), respectively. The molecular weights of the prepared polyesters were determined by the end group analysis. These polyesters were diluted with styrene / acrylonitrile (AN) mixture to prepare curable resins with inhibited premature gelation. The effect of the structure of the resins on their curing behavior and mechanical properties has been investigated.     

Mechanical characterization and chemical resistances of cured unsaturated polyester resins modified with vinyl ester resins based on recycled poly(ethylene terephthalate)

Unsaturated polyester resin (UP) was prepared from glycolyzed oligomer of poly(ethylene terephthalate) (PET) waste based on diethylene glycol (DEG). New diacrylate and dimethacrylate vinyl ester resins prepared from glycolysis of PET with tetraethylene glycol were blended with UP to study the mechanical characteristics of the cured UP. The vinyl ester resins were used as crosslinking agents for unsaturated polyester resin diluted with styrene, using free‐radical initiator and accelerator. The mechanical properties of the cured UP resins were evaluated. The compressive properties of the cured UP/styrene resins in the presence of different vinyl ester concentrations were evaluated. Increasing the vinyl ester content led to a pronounced improvement in the compression strength. The chemical resistances of the cured resins were evaluated through hot water, solvents, acid, and alkali resistance measurements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3175–3182, 2007     

Synthesis and properties of UV-curable waterborne unsaturated polyester for wood coating

UV-curable waterborne unsaturated polyesters for wood coatings were prepared. The effects of different polyols and acids on the properties of the UV-curable waterborne unsaturated polyesters were investigated. Several different unsaturated polyester prepolymers were prepared from three different polyols [ethylene glycol (EG), diethylene glycol (DEG), and propylene glycol (PG)] and three different acids [tetrahydrophthalic anhydride (THPAn), terephthalic acid (TPA), and trimellic anhydride (TMAn)]. UV-curable coating materials were formulated from the prepolymers and 2-hydroxy-2-methylphenyolpropane-1-one as a photoinitiator with distilled water as a diluent. Trimethylolpropane diallyl ether was used as an air inhibitor of cure. The dynamic mechanical studies showed the properties of those unsaturated polyesters were well correlated with their glass transition temperature behaviors. It was found that the unsaturated polyester prepared with 60/40 (mol %) TMAn/THPAn and the equimolar mixture of EG, DEG, and PG showed balanced coating properties such as good tensile properties and weatherability, as well as proper viscosity (ca. 2500 cps) when using distilled water as a diluent. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 695–708, 1998     

Synthesis of unsaturated polyester resin from postconsumer PET bottles: Effect of type of glycol on characteristics of unsaturated polyester resin

Postconsumer PET bottles including water and soft‐drink bottles were depolymerized by glycolysis in excess glycols, such as ethylene glycol, propylene glycol, and diethylene glycol, in the presence of a zinc acetate catalyst. The obtained glycolyzed products were reacted with maleic anhydride and mixed with a styrene monomer to prepare unsaturated polyester (UPE) resins. These resins were cured using methyl ethyl ketone peroxide (MEKPO) as an initiator and cobalt octoate as an accelerator. The physical and mechanical properties of the cured samples were investigated. It was found that the type of glycol used in glycolysis had a significant effect on the characteristics of the uncured and cured UPE resins. Uncured EG‐based UPE resin was a soft solid at room temperature, whereas uncured PG‐ and DEG‐based resins were viscous liquids. In the case of the cured resins, the EG‐based product exhibited characteristics of a hard and brittle plastic, while the PG‐based product did not. The DEG‐based product exhibited characteristics of hard and brittle plastic after strain‐induced crystallization had occurred. In addition, it was also found that no separation of the type of bottles was needed before glycolysis, since UPE resins prepared from water bottles, soft‐drink bottles, and a mixture of both bottles showed the same characteristics. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 788–792, 2003     

Synthesis and characterization of unsaturated polyesters based on the aminolysis of poly(ethylene terephthalate)

The depolymerization of poly(ethylene terephthalate) via an aminolysis process was studied. An excess of ethanol amine in the presence of sodium acetate as a catalyst was used to produce bis(2‐hydroxyl ethylene) terephthalamide (BHETA). Unsaturated polyester (UP) resins were obtained by the reaction of BHETA with different long‐chain dibasic acids such as decanedioic acid, tetradecanoic acid, and octadecanoic acid in conjunction with maleic anhydride as a source of unsaturation. The chemical structure of the UP resins was confirmed by ¹H‐NMR. The vinyl ester resins were used as crosslinking agents for UP. The curing behavior and mechanical properties of the UP resins with vinyl ester were evaluated at different temperatures ranging from 25 to 55°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Unsaturated Polyester Resins Obtained from Glycolysis Products of Waste PET

Abstract

Waste polyethylene terephthalate (PET) flakes were depolymerized by using ethylene glycol (EG), propylene glycol (PG), diethylene glycol (DEG), and triethylene glycol (TEG) in the presence of zinc acetate as catalyst. All glycolysis products were reacted with maleic anhydride and mixed with styrene monomer to get unsaturated polyester (UP) resins. Molecular weights of all synthesized UP resins were determined by end-group analysis. The curing characteristics such as gel time and maximum curing temperatures, and mechanical properties such as hardness, tensile strength, and elastic module of these resins were investigated. The waste PET resins were compared with the reference resins prepared with the same glycols and the properties of the resins were found to be compatible with the properties of the reference resins.     

Synthesis and applications of unsaturated polyester resins based on PET waste

Three types of unsaturated polyester resins were synthesized from the glycolysis of polyethylene terephthalate (PET) plastic waste, considering environment, cost and properties for their applications. These synthesized unsaturated polyester resins could be used for various construction processes and materials such as no dig pipelining (NDR-1), pultrusion (PLR-1) and polymer concrete (PCR-1). PET was taken from common soft-drink bottles, and ethylene glycol (EG), diethylene glycol (DEG) and MPdiol glycol mixtures were used for the depolymerization at molar ratios. The glycolyzed PET 1 ^st products (oligomers) were reacted with maleic anhydride, phthalic anhydride and dicyclopentadiene (DCPD) (especially for polymer concrete) to form unsaturated polyester resins with mixed styrene. The lab scale (1–5 kg) and pilot plant scale-up tests (200 kg) were experimented to evaluate the processing characteristics, viscosity, acid number and curing behaviors. The main properties such as hardness, flexural strength, tensile strength, heat distortion temperature, elongation, and chemical resistance were determined based on the various uses of the three resins. Furthermore, the applicability and the properties of these developed resins were verified through many real application tests.     

Mechanical properties and curing characteristics of unsaturated polyesters synthesized for large casting

Summary A series of unsaturated polyesters (UP) based on phthalic anhydride (PHA), succinic acid (SU), adipic acid (AD), sebacic acid (SE), maleic anhydride (MA), ethylene glycol (EG), diethylene glycol (DG), triethylene glycol (TG), and styrene (Sty) were prepared. The molecular weights of the prepared polyesters were determined by the end group analysis. The effect of the structure of the resin on its mechanical and curing behavior has been investigated. On the basis of the experimental study, we concluded: (1) the maximum curing temperature, T_max, is related to the molecular weight of the glycol incorporated in these castings. In this context, T_max was found to decrease with increasing the molecular weight. Meanwhile, the time to peak temperature, t_max, was increasing; (2) the values of T_max, Young's modulus and compressive strength were found to be influenced to a large extent with the type of the saturated acid as well as the molecular weight of the glycol embodied in these resins. A relation representing the variation of compressive strength, _u, as a function of equivalent polymerizable double bonds, EPDB, was derived. It was assumed that this equation can be used to predict the compressive strength for any particular UP formula from its theoretical EPDB value.     

萜烯基聚酯丙烯酸酯的合成及性能研究

以萜烯马来酸酐(TMA)、DCPD、顺酐(MA)、乙二醇(EG)、丙二醇(PG)、丙烯酸(AA)为主要原料,通过三步法合成了聚酯丙烯酸酯。通过红外光谱分析仪、动态机械分析仪和TG研究了不同原料配比、缩聚反应时间、阻聚剂用量对涂膜性能的影响。结果表明,该光固化涂膜具有良好的力学性能、耐化学性能和耐热性,且固化速度快,可单独作为UV固化的预聚物使用。     

Toughening of unsaturated polyester resins with core–shell rubbers

The effects of core–shell rubbers (CSRs) as tougheners on the fracture properties of unsaturated polyester (UP) resins during curing at 110°C are investigated. CSRs were synthesized by two‐stage soapless emulsion polymerizations; the soft core was made from rubbery poly(n‐butyl acrylate), whereas the hard shell was made from methyl methacrylate, ethylene glycol dimethacrylate, and various concentrations of glycidyl methacrylate. Depending on the content of glycidyl methacrylate in the CSR shell and the amount of CSR added to the UP, the fracture properties of the CSR‐toughened UP resins varied. The experimental results are explained by an integrated approach of measurements of the static phase characteristics of a styrene/UP/CSR system, the reaction kinetics, the cured sample morphology, the glass‐transition temperatures, and the fracture toughness with differential scanning calorimetry, scanning electron microscopy, transmission electron microscopy, and dynamic mechanical analysis. Finally, the toughening mechanism for the CSR‐toughened UP resins is also explored. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Physical properties of unsaturated polyester resin from glycolyzed pet fabrics

Physical properties of unsaturated polyester resins (UPE resins) prepared from glycolyzed poly (ethylene terephthalate) (PET) and PET/cotton blended fabrics were investigated. Initially, PET and PET/cotton blended fabrics were chemically recycled by glycolysis. The depolymerizations were carried out in propylene glycol with the presence of zinc acetate as a catalyst. The reaction time was varied at 4, 6, and 8 h. The glycolyzed products were then esterified using maleic anhydride to obtain UPE resins. The prepared resins were cured using styrene monomer, methyl ethyl ketone peroxide, and cobalt octoate as a crosslinking agent, an initiator and an accelerator, respectively. The cured resin products were tested for their mechanical properties and thermal stability. The results indicated that, among the fabric based resins, one prepared from the 8‐h glycolyzed product possessed the highest mechanical properties those are tensile strength, tensile modulus, flexural strength, impact strength, and hardness. The highest thermal stability was also found in the cured resin prepared from the 8‐h glycolyzed product. The mechanical properties of fabric based resins were slightly lower than those of the bottle based resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2536–2541, 2007     

Synthesis,characterization, thermal,and viscoelastic properties of an unsaturated epoxy polyester cured with different hardeners

The chemical modification of the structure of the unsaturated polyester obtained in poly condensation process of 1,2,3,6‐tetrahydrophthalic anhydride, maleic anhydride, and ethylene glycol by well known conventional method of epoxidation with peracetic acid in mild conditions has been presented. The new material containing both epoxy groups and unsaturated double bonds in polyester chain was characterized by FTIR and ¹H NMR spectra. The prepared unsaturated epoxy polyester was suitable material for further chemical modification. Both epoxy groups and unsaturated double bonds can be used as cross‐linking sites. Curing behavior, thermal, and visco‐elastic properties of the unsaturated epoxy polyester cured with different hardeners: 1,2,3,6‐tetrahydrophthalic anhydride (THPA), hexahydrophthalic anhydride (HHPA), and/or with vinyl monomer (styrene) using radical initiator—benzoyl peroxide (BPO) were studied by differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), and dynamic mechanical analysis (DMA). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

马来海松酸新戊二醇酯多元醇的制备及性能

马来海松酸酐(MPA)具有良好的耐热性能,被用作制备耐热多元醇的原料而得到广泛研究.实验将含有耐热基团的新戊二醇(NPG)和MPA制备多元醇酯,以进一步提高产品的耐热性能.研究了反应体系的酸值变化,通过改变NPG与MPA的摩尔比,得到了具有较大羟值范围的系列产品.对产品进行了红外和热重表征.结果表明,MPA的三个羧基均发生了酯化反应,且反应较为彻底.酯化产物具有较高的初始失重温度,可作为耐热原料使用.     

Replacement of styrene with acrylated epoxidized soybean oil in an unsaturated polyester resin from propylene glycol,isophthalic acid,and maleic anhydride

Commercial unsaturated polyester (UPE) resins typically contain a high amount of volatile toxic styrene. A non‐volatile acrylated epoxidized soybean oil (AESO) was found to be an excellent replacement of styrene in a commercially available UPE resin [designated as Styrene‐(PG‐IPA‐MA)] that is derived from propylene glycol (PG), isophthalic acid (IPA), and maleic anhydride (MA) in terms of the mechanical properties of the resulting kenaf fiber‐reinforced composites. The AESO‐(PG‐IPA‐MA) resins had low viscosity and long pot life below 70°C for a typical fiber‐reinforced composite application. AESO and PG‐IPA‐MA were not able to form a strong polymer matrix individually for fiber‐reinforced composites. However, a combination of AESO and PG‐IPA‐MA saw strong synergistic effects between them. The flexural, tensile, and water absorption properties of kenaf fiber‐reinforced composites made from AESO‐(PG‐IPA‐MA) resins were comparable with or even superior to those from the Styrene‐(PG‐IPA‐MA) resin. The AESO/(PG‐IPA‐MA) weight ratio was investigated for maximizing the mechanical properties of the kenaf fiber‐reinforced composites. The curing mechanism of the AESO‐(PG‐IPA‐MA) resins is discussed in detail. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43052.     

Mechanical,thermal, and morphological properties of bismaleimide/unsaturated polyester copolymers

An unsaturated polyester (UP) resin was modified by the addition of a thermosetting bismaleimide (BMD) as a second coreactive monomer. The copolymers were characterized in terms of mechanical, thermal, and morphological properties by tensile, bend, and impact testing; thermogravimetric analysis; heat deforming temperature analysis; dynamic mechanical analysis; and scanning electron microscopy. In addition, Fourier transform infrared spectroscopy of modified resin indicated that crosslinking networks were formed between BMD and UP. The properties of the modified resins were compared with those of unmodified resins. The results indicate that the addition of BMD not only improved the thermal decomposition temperature and heat deforming temperature but also caused small changes in the mechanical properties. The effect of the construct of BMD and the reactions among BMD, UP, and styrene were analyzed. The results show that BMD has great potential to improve the properties of UP. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 593–598, 2006     

Deciphering the structure of itaconate‐based unsaturated polyester resins by high resolution mass spectrometry

Unsaturated polyester (UP) resins are widely used to manufacture composite materials and fulfil a wide panel of specification for industrial or domestic applications at low cost. These resins consist of a highly viscous polyester oligomer and a reactive diluent, which allow their processability and crosslinking. The oligomers are synthesized from diols and saturated or unsaturated diacids. Maleic anhydride is classically used as an unsaturated acid because of its reactivity for esterification and its competitive cost. However, maleic anhydride is petroleum based and classified as skin and respiratory sensitizing by the European Chemicals Agency. Itaconic acid which is recognized as one of the top 12 biobased molecules by the US Department of Energy is a biobased alternative with a reactive unsaturation. In this work, a UP based on propylene glycol, itaconic acid and dimethyl terephthalate was synthesized by polycondensation and characterized by high resolution mass spectroscopy, ¹H, ¹³C 1D and 2D NMR as well as ion mobility spectrometry mass spectrometry. The main structures were linear but cyclic species and a few branched chains due to the intermolecular Ordelt reaction were also detected by NMR and high resolution mass spectroscopy. Molecular modelling has indeed demonstrated that itaconate‐based UPs are more prone to cyclization than fumarate‐based UPs. Moreover, NMR analysis showed a significant consumption of itaconate unsaturation by the Ordelt reaction. Ion mobility spectrometry mass spectrometry allowed an additional structure to be distinguished for the same m/z peaks first attributed to a linear structure only. These results suggest the existence of cyclic species based on an intramolecular Ordelt reaction. © 2020 Society of Chemical Industry     

Mechanical characteristics of modified unsaturated polyester resins derived from poly(ethylene terephthalate) waste

The depolymerization of poly(ethylene terephthalate) (PET), by an alcoholysis reaction is an easy operation and gives prospects for the utilization of wastes. PET waste was first depolymerized by glycolysis reaction at three different molar ratios of diethylene glycol (DEG), in the presence of manganese acetate as a transesterification catalyst. Copolyesters of PET modified with varied mole ratios of p‐hydroxybenzoic acid (PHBA) were reported to exhibit excellent mechanical and chemical properties due to their liquid crystalline behaviour. Here we study the effect of incorporating (PHBA) units into the building structures of different unsaturated polyesters synthesized originally from glycolysed PET waste. Modified unsaturated polyesters were synthesized by depolymerizing PET with DEG, and the obtained oligoesters were reacted with PHBA and maleic anhydride (MA). The molar ratio of the added PHBA was varied to investigate its effect on the mechanical characteristics of these modified unsaturated polyesters. The data obtained reveal that increasing the molar ratio of PHBA within the studied range of concentrations leads to a pronounced improvement in the mechanical characteristics, which is represented mainly by the values of/maximum compression strength (σ_max) and Young's modulus (E_Y). © 2002 Society of Chemical Industry     

Replacement of styrene with acrylated epoxidized soybean oil in an unsaturated polyester resin from propylene glycol and maleic anhydride

A nonvolatile, vegetable‐oil based chemical, acrylated epoxidized soybean oil (AESO) was investigated as a replacement of volatile and toxic styrene in one of commercial UPE resins styrene‐(PG‐MA) that is a mixture of styrene and a UPE plastic from propylene glycol and maleic anhydride (PG‐MA). Neither AESO nor PG‐MA was capable of forming a strong matrix, respectively, for glass fiber‐reinforced composites. However, a mixture of AESO and PG‐MA resulted in glass fiber‐reinforced AESO‐(PG‐MA) composites that were comparable or even superior to those from styrene‐(PG‐MA) in terms of the flexural and tensile properties. Effects of AESO contents on the mechanical and viscoelastic properties of the glass fiber‐reinforced AESO‐(PG‐MA) composites were investigated. Resin viscosity and resin pot life as a function of temperature were studied. The curing mechanism of the AESO‐(PG‐MA) resins is also discussed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45056.