Curing reaction of saturated aliphatic polyester modified unsaturated polyester resins

Two series of unsaturated polyesters (UPE from isophthalic acid, fumaric acid, and propylene glycol) were prepared. In series-A resins, UPEs wee thickened with isocyanate-terminated saturated aliphatic polyestes, i.e., an isocyanate-terminated polycaprolactone diol (PE-di-OL), through reaction of the isocyanate group with the hydroxyl group of the UPE. In series-B resins, the UPEs were mixed with saturated aliphatic polyesters i.e., PE-di-OL. The curing reaction of these two series of UPEs with styrene was studied by using differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). The DSC data show that for a fixed PE-di-OL molecular weight, the curing reaction rate of series-A UPE is faster than that of series-B UPE. The variation of microgel size during curing ws studied by GPC. These results revealed that microgel formation has a great effect on the kinetics of cure for the unsaturated polyester-styrene system. The curing of these two series of UPEs is found to strongly depend on the compatibility of the components in the curing system.     

Preparation and characterization of some new unsaturated polyesters based on 3,6‐bis(methoxymethyl)durene

A series of unsaturated polyester resins based on 3,6‐bis(methoxymethyl)durene with different diacids or anhydrides, namely, phthalic anhydride, maleic anhydride, and succinic acid, and different glycols, namely, 1,2‐propylene glycol, triethylene glycol, 1,4‐cyclohexane diol, and 3,6‐bis(benzyloxymethyl)durene, were prepared. Infrared and nuclear magnetic resonance spectra were used to characterize the unsaturated polyester resins obtained qualitatively and quantitatively. The average‐number molecular weight (M^?_n) was determined by end‐group analysis. These polyesters were found to cure with styrene at room temperature. The thermal behavior of the styrenated polyesters was studied via thermogravimetrical analysis and differential scanning calorimetry (TGA and DSC). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3388–3398, 2001     

Unsaturated polyester resins from poly(ethylene terephthalate) waste for polymer concrete

Depolymerization of poly(ethylene terephthalate), PET, textile waste was performed with a manganese acetate catalyst. Different ratios of diethylene glycol (DG) to propylene glycol (PG) were used for glycolysis. The weight ratio of PET to the glycol mixture was 1:0.65. The glycolyzed products were analyzed for hydroxyl value and the amount of free glycol. These glycolyzed products were reacted with mixtures of sebacic acid (SE) and maleic anhydride (MA) to prepare a series of unsaturated polyesters having different molecular weights. The molecular weights of the unsaturated polyesters produced were determined by the end group analysis. The obtained polyesters were dissolved in styrene (Sty) monomer and their curing behavior was investigated. Polymer concretes (PC) made with these resins were investigated for their compressive strength. The data revealed that the properties of the PC based on recycled PET are comparable to PC made from virgin materials. We concluded that recycling of PET waste may provide a potentially lower cost source of resin, and its recycling in PC will also help reduce an environmental problem.     

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     

Unsaturated polyester based on poly(ethylene glycol)

Unsaturated polyesters were prepared by one-stage melt condensation of maleic anhydride, phthalic anhydride, propylene glycol, and poly(ethylene glycol)s with different molecular weight, and the properties of their castings from styrenated resins were investigated. Tensile and flexural properties decrease with the increase of molecular weight of poly(ethylene glycol), but impact strength, elongation, and water absorption have an inverse effect. This study improves the understanding of the effect of chain length of poly(ethylene glycol) in unsaturated polyester on the properties of its castings.     

Chemical modification of unsaturated polyesters influence of polyester's structure on thermal and viscoelastic properties of low styrene content copolymers

In this study, the chemical modification of unsaturated polyesters and the influence of polyester's structure on thermal and viscoelastic properties have been presented. The structure of unsaturated polyesters obtained in polycondensation of cyclohex‐4‐ene‐1,2‐dicarboxylic anhydride (THPA), maleic anhydride and only one suitable symmetrical glycol: ethylene glycol or 1,4‐butanediol (BDO) or 1,6‐hexanediol has been modified by peracetic acid. The selective oxidation of unsaturated polyesters conducted in mild time and temperature conditions was a successful and effective method to prepare new materials/unsaturated epoxy polyesters/containing epoxy groups in cycloaliphatic rings and carbon–carbon double bonds in polyester chain. The unsaturated epoxy polyesters were capable of both copolymerization with vinyl monomer and polyaddition reactions with suitable curing agent. Therefore, they were successfully used as a component of low styrene content copolymers. As was confirmed by DSC, DMA, and TGA analyses, polyester's structure had significant influence on thermal and viscoelastic properties of styrene copolymers. The properties of styrene copolymers prepared from unsaturated epoxy polyesters were considerably better compared with those obtained for styrene copolymers from unsaturated polyesters.© 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effects of chemical composition and structure of unsaturated polyester resins on the miscibility, cured sample morphology and mechanical properties of styrene/unsaturated polyester/low-profile additive ternary systems: 2. Mechanical properties

The effects of three series of unsaturated polyester (UP) resins with different chemical composition or structure on the mechanical properties of three low-shrink UP resins containing thermoplastic polyurethane, poly(vinyl acetate) and poly(methyl methacrylate) respectively have been investigated by an integrated approach of static phase characteristics–cured sample morphology–reaction conversion–property measurements. The three series of UP resins synthesized include: maleic anhydride (MA)–neopentyl glycol (NPG)–diethylene glycol (DEG) types, with various molar ratios of NPG and DEG; MA–1,2-propylene glycol (PG) types with and without modification by a saturated dibasic aromatic anhydride or acid, such as phthalic anhydride (PA) or isophthalic acid; and MA–PA–PG types modified by a second glycol, such as DEG, 2-methyl-1,3-propanediol or NPG, to partially replace PG. Based on the Takayanagi mechanical models, the effects of glycol ratios, saturated dibasic aromatic acid modification, second glycol modification, C=C unsaturation of UP and molecular weight of UP on the mechanical properties will be discussed.     

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.     

不饱和脂肪族聚酯生物降解性的研究

以1，4-反丁烯二酸和一缩二乙二醇（DEG）为原料，采用缩聚法合成端羟基不饱和聚酯，并采用红外光谱分析（FT—IR）、羟值、酸值、黏度等对所得聚合物进行表征，确认了其分子结构．对其降解性进行研究，并且与1，4-丁二酸与一缩二乙二醇合成的饱和脂肪族聚酯进行了对比。研究结果表明，不饱和脂肪族聚酯和饱和脂肪族聚酯的生物降解性差别不大，也就是双键的引入对其生物降解性没有大的影响；但是不饱和脂肪族聚酯膜经过高温处理后，双键会打开发生交联，而交联后的不饱和脂肪族聚酯的生物降解性变差，而且交联度越高，生物降解性越差。     

Synthesis and properties of a new type of unsaturated poly(ester amide)

A new type of unsaturated poly(ester amide), maleic anhydride–phthalic anhydride–ethylene glycol–neopentylene glycol–anthranilic acid copolymer, was prepared by melt polycondensation. The copolymer was characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. The viscosity of the polymer was measured with a Ubbelohde viscometer. The compressive strength of the crosslinked unsaturated poly(ester amide) under different heat‐treatment conditions was measured. Studies of its degradation behavior were carried out in simulated body fluid at pH 7.4 (37°C), and the compressive strength loss of the crosslinked unsaturated poly(ester amide) was also measured after different degradation times. The copolymer was hydrolyzed in a 1.0‐mol/L NaOH standard solution at room temperature. All of the preliminary results suggest that the new unsaturated poly(ester amide) might potentially be used as a new type of bone‐fixation material. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Polyester resins with carbazole ring

3‐(9‐Carbazolyl)propane‐1,2‐diol was obtained in the reaction of 9‐(2,3‐epoxypropyl)carbazole with water. The obtained diol was further used for modification of unsaturated polyester resin to produce enhanced thermal and heat resistance in comparison with classic resins. The properties of polyesters and polyester resins modified with 3‐(9‐carbazolyl)propane‐1,2‐diol were studied in detail. When 3‐(9‐carbazolyl)propane‐1,2‐diol is used instead of propylene glycol the unsaturated polyester resins possess enhanced thermal stability.© 2013 Society of Chemical Industry     

聚氨酯型不饱和聚酯树脂的合成及其性能的研究

采用两步法由二元醇、二元酸酐和甲苯二异氰酸酯(TDI)合成了一种聚氨酯型不饱和聚酯树脂(UPPU)。第一步由二元醇和二元酸酐合成出以—OH封端的不饱和聚酯(UP);第二步利用UP的—OH与TDI的—NCO的高反应活性由UP与TDI合成UPPU。同时研究了反应温度、反应时间、原料配比等对UPPU树脂涂膜性能的影响。结果表明,当乙二醇:邻苯二甲酸酐:顺丁烯二酸酐物质的量比为1.2:0.7:0.3,反应温度为205℃,反应时间8 h,酸值在40mgKOH/g以下时,得到UPPU树脂涂膜性能较好。     

Methacrylate monomer as an alternative to styrene in typical polyester–styrene copolymers

This study presents the research on the influence of crosslinking monomers [styrene and diethylene glycol dimethacrylate (DEGDMA)] on the properties of unsaturated polyester resins (UPRs). Syntheses of the unsaturated polyesters (UPs) modified with benzyl alcohol were carried out. Then, each polyester was used in preparation of five resin solutions with different amounts of crosslinking monomers acting as reactive diluents. These diluents improve the processability of UPs reducing their viscosities. They also take part in crosslinking of resins during copolymerization process. The properties of the prepared UPRs systems were investigated before and after the curing process. The measurements of their viscosity, reactivity, mechanical properties, thermal stability (thermogravimetry), and dynamic mechanical analysis were performed. Resins where DEGDMA was used as reactive diluent were characterized by the largest viscosities in comparison to styrene ones. The type of the used monomer influenced also degree of the resin crosslinking. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47735.     

Calcium polyphosphate fibers/unsaturated poly(ester‐amide) composites for bone‐fixation materials

A new type of unsaturated poly(ester‐amide) viz maleic anhydride‐phthalic anhydride‐propylene glycol‐neopentylene glycol‐glycin copolymer was prepared by melt polycondensation and characterized after sealed end with cyclohexanol. Mechanical strength of the crosslinked unsaturated poly(ester‐amide) with different heat‐treatment conditions was measured. Calcium polyphosphate fibers (CPPF) were used to boost up the new unsaturated poly(ester‐amide), mechanical strength, degradation, and hydrolysis behavior of CPPF/unsaturated poly(ester‐amide) composites with different CPPF content were measured. All the preliminary results suggested that the CPPF/unsaturated poly(ester‐amide) composites might be potentially used as a new type of bone‐fixation material. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

New modified polyesteramide resin for industrial applications

Polyesteramide resins (PEA) combine the properties of both polyester and polyamide resins. These resins may be modified with various polyhydric alcohols to produce resins with modified properties. Hydroxy ethyl fatty acid amide (HEFA) is the main source of polyhydric alcohol used in polyesteramide resins. New modified polyesteramide resins were prepared and evaluated as anticorrosive varnish for industrial applications by partial replacement of hydroxy ethyl fatty acid amide (HEFA) with polyethylene glycol (PEG₄₀₀) without affecting the resin constants. Primer formulations based on these modified resins improve the films properties and show good physicochemical and corrosion inhibiting properties.     

New intramolecular effect observed for polyesters: An anomeric effect

A series of polyesters was prepared to evaluate hydrolytic stability as a function of cyclohexyl dibasic acid content. The three cyclohexyl dibasic acids: 1,2; 1,3; and 1,4 were formulated into polyesters with two glycols. The proportion of cis and trans isomers was evaluated via ¹H NMR. The hydrolytic stability of short chain polyesters was evaluated in an acetone/water mixture which solubilized the polyesters to mimic oligoester behavior within a thermosetting polyester coating environment. The rate of hydrolysis was monitored by acid titration and corroborated by GPC. Surprisingly, 1,2-cylohexyl diacid-based polyesters were robust, and 1,3-cyclohexyl diacid-based polyesters were the most susceptible to hydrolysis. Evidently, a 1,2-anchimeric effect for cyclohexyl dibasic acid polyesters was not an important consideration, while the 1,3-cyclohexyl ester interaction was. Consequently, an anomeric effect was proposed. Presented at the 81st Annual Meeting of the Federation of Societies for Coatings Technology, November 12–14, 2003, in Philadelphia, PA.     

Saturated and unsaturated polyesters based on 1,3-(dicarboxymethoxy)benzene

Saturated polyesters were prepared by the reaction of 1,3-(dicarboxymethoxy)benzene with ethylene, diethylene, tetramethylene, and hexamethylene glycols. Also, unsaturated polyesters were prepared by the reaction of 1,3-(dicarboxymethoxy)benzene and maleic anhydride with the same glycols. All the polyester resins obtained have been characterized, and the unsatureated polyesters were found to cure with styrene. The properties of the cured polyesters in the form of films were determined. IR and ¹H-NMR spectroscopy were used for both qualitative and quantitative analyses of the polyesters as well as their hydrolyzate products, after curing with styrene.     

Preparation and characterization of water‐extended polyester based on recycled poly(ethylene terephthalate)

An unsaturated polyester resin was prepared that was based on the reaction of oligomers obtained from the depolymerization of poly(ethylene terephthalate) waste products, with both maleic anhydride and sebacic acid. The structure of the produced polyester was compared with that prepared from the reaction of dimethyl terephthalate with both maleic anhydride and sebacic acid with IR and NMR spectroscopy. Water‐extended polyester resins were prepared from these two polyesters through curing with styrene in the presence of various amounts of water with benzoyl peroxide as an initiator. The mechanical properties of the prepared water‐extended polyesters, as well as scanning electron microscopy, were investigated. The use of water‐extended polyesters based on recycled poly(ethylene terephthalate) waste for the preparation of decorative art objects and statues was investigated. Therefore, three pharaonic statues representing Tutankhamen, Nefertiti, and a black head of a cat were prepared. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3693–3699, 2003     

Synthesis of polymers by using divalent metal salts of mono(hydroxyethyl) phthalate: Unsaturated polyesters from metal salts,glycol, anhydrides,and epoxides

Syntheses of unsaturated polyesters were investigated by the divalent metal salts of mono(hydroxyethyl) phthalate–ethylene glycol–anhydrides–epoxide reactions. As anhydrides, phthalic anhydride and maleic anhydride were used, and propylene oxide and 1,2-butylene oxide were the epoxides used. The metal carboxylate groups of the above metal salts catalyzed the reaction. Viscosities of styrene solutions of the polyesters obtained showed a tendency to increase with increase in metal content. The styrene solutions could be cured to give metal-containing cured polyester resins. The cured resins were evaluated for physical properties. Generally, Mg was more effective than Ca in improving the physical properties. Further, resistance to chemical attack and boiling water and thermal behavior were also discussed.     

The stability of solutions in reactive monomers of crosslinkable polyesters containing bisacid A2

Earlier papers^1–6 have dealt with the synthesis and purification of bisacid A2; the preparation of unsaturated polyesters by cocondensing bisacid A2 with maleic anhydride in varying proportions in the presence or absence of phthalic anhydride as a further modifying acid, using propylene glycol as the polyesterification diol; the hardness and the thermal and mechanical properties of cast, cured resins and glass fiber-reinforced laminates; and the water and chemical resistance of the cured resins. This paper deals with the solution stability of the liquid resins prior to cure and, in particular, with the observed fact that solutions containing esters of bisacid A2 in sufficient quantity do not require the addition of stabilizers commonly needed for commercial polyesters in order to impart an acceptable shelf life to the liquid resins.