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.     

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 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     

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     

Unsaturated polyester resins based on rosin maleic anhydride adduct as corrosion protections of steel

Unsaturated polyester resin (UP), based on 1 mol maleopimaric adduct (MPA), 1 mol maleic anhydride, 1 mol isophthalic acid, 1 mol adipic acid, 1 mol propylene glycol, and 1 mol diethylene glycol, were obtained at various times during polyesterification. They were characterized by ¹H NMR and chemical titration. Increasing the reaction time to 8 h led to an increase in (a) the number-average molar mass (Mn), (b) the glass transition temperature (T_g) and (c) the compatibility with styrene. Several of these fractions were cured with styrene, in amount of UP/ST = 2.5 (weight of styrene, ST, and unsaturated polyester, UP), using initiator and activator. 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. The corrosion resistance of cured films was evaluated using salt fog resistance test.     

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     

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.     

Investigation of the effect of hydrolysis products of postconsumer polyethylene terephthalate bottles on the properties of alkyd resins

Hydrolysis of waste polyethylene terephthalate (PET) flakes obtained from grinding postconsumer bottles was carried out at 200–230°C and molar ratios of PET/H₂O were taken as 1/5; 1/10; 1/20. The reaction products, when extracted with boiling water, yielded a water soluble crystallizable fraction (WSCF) and a water insoluble fraction (WIF). These fractions were characterized by acid and hydroxyl value determinations and DSC analysis. WSCF and WIF were used for preparation of alkyd resins. Five long oil alkyd resins were prepared from phthalic anhydride (PA) (reference alkyd resin) or hydrolysis products of the waste PET (PET‐based alkyd resin), pentaerithrithol (PE), soybean oil fatty acid (SOFA), and ethylene glycol (EG). Film properties and thermal degradation stabilities of these alkyd resins were investigated. Drying time, hardness, alkaline resistance, and thermal oxidative degradation resistance of the PET‐based alkyd resins are better than these properties of reference resin. The results show that hydrolysis products of waste PET obtained from postconsumer bottles are suitable for manufacturing of alkyd resins. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

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.     

光固化粉末涂料涂膜性能研究

以不饱和聚酯和丙烯酸环氧树脂为光固化粉末涂料的基体树脂,研究了两种基体树脂的结构、配比对光固化涂膜固化度及其性能的影响。结果表明固化度是影响耐溶剂性能、附着力、涂膜硬度和冲击强度的关键,适宜的n(UP)/n(EA)为1∶1;固化度应大于95%,可以达到99%。     

New epoxy resins based on recycled poly(ethylene terephthalate) as organic coatings

Glycolysis of poly(ethylene terephthalate), PET, waste using trimethylol propane (TMP), triethanolamine (TEA), diethylene glycol (DEG) and diethanolamine (DEA) was used to produce suitable hydroxy-oligomers for epoxy. The glycolyzed products were reacted with epichlorohydrine to prepare a series of di- and tetraglycidyl epoxy resins with different molecular weights. The glycolysis was carried out in presence of manganese acetate as a catalyst at normal and high pressure in presence and absence of xylene at 210 °C. The produced resins were cured with different mole ratios of 1-(2-amino ethyl) piprazine as curing agent at room temperature. The mechanical properties of the cured epoxy resins were evaluated. The chemical resistances of the cured resins were evaluated through salt spray resistance, hot water, solvents, acid and alkali resistance measurements. The data indicate that the cured epoxy resins based on glycolyzed oligomer of PET and DEA have excellent chemical resistances as organic coatings among other cured resins.     

Alkyd resins based on waste PET for water-reducible coating applications

Simultaneous glycolysis and neutral hydrolysis of waste PET flakes obtained from grinding post-consumer bottles was carried out in the presence of xylene and an emulsifier at 170 °C. The product was separated from ethylene glycol (EG), water, and xylene by filtration, and was extracted by water at boiling point thrice. The remaining solid was named water insoluble fraction (WIF). The filtrate was cooled to 4 °C, and the crystallized solid obtained by filtration was named water soluble crystallizable fraction (WSCF). These fractions were characterized by acid value (AV) and hydroxyl value (HV) determinations. WSCF and WIF were used for preparation of the water-reducible alkyd resins. Three long oil alkyd resins were prepared from phthalic anhydride (PA; reference alkyd resin) or depolymerization product of the waste PET (PET-based alkyd resin), glycerin (G), fatty acids (FA), and glycol (EG; reference alkyd resin) or depolymerization product of the waste PET (PET-based alkyd resin). Film properties and thermal degradation stabilities of these alkyd resins were investigated. Physical properties (drying times and hardness) and thermal degradation stabilities of the PET-based alkyd resin is better than these properties of the reference alkyd resin.     

Alkyd resins synthesized from postconsumer PET bottles

Simultaneous glycolysis and neutral hydrolysis of waste PET flakes obtained from grinding postconsumer bottles was carried out in the presence of xylene and an emulsifier at 180 °C. The product was separated from EG, water and xylene by filtration and was extracted by water at boiling point three times. The remaining solid was named water insoluble fraction (WIF). The filtrate was cooled to 4 °C and the crystallized solid obtained by filtration was named water-soluble crystallizable fraction (WSCF). These fractions were characterized by acid value (AV), hydroxyl value (HV) determinations. WSCF and WIF were used for preparation of the alkyd resins. Three long oil alkyd resins were prepared from phthalic anhydride (PA) (reference alkyd resin) or depolymerization product of the waste PET (PET-based alkyd resin), glycerin (G), sunflower oil fatty acids (SOFA) and glycol (EG) (reference alkyd resin) or depolymerization product of the waste PET (PET-based alkyd resin). Film properties and thermal degradation stabilities of these alkyd resins were investigated. Physical properties (drying times, hardness and abrasion resistance) and thermal degradation stabilities of the PET-based alkyd resins are better than these properties of the reference alkyd resin.     

The use of aminolysis,aminoglycolysis, and simultaneous aminolysis–hydrolysis products of waste PET for production of paint binder

This work is concerned with the use of aminolysis, aminoglycolysis, and simultaneous aminolysis–hydrolysis products of waste PET for production of paint binder based on alkyd resin. For this purpose, first, aminolysis, aminoglycolysis, and simultaneous hydrolysis–aminolysis reactions of waste PET were carried out in the presence of different chemical agents in xylene medium at high pressures. Reactions of waste PET flakes obtained from grinding postconsumer water bottles were carried out in an autoclave at higher temperatures. Then, four alkyd resins, formulated to have oil content 40–50%, were prepared using these depolymerization products. One of resins is “reference alkyd resin” which was prepared by using soybean oil fatty acid, phthalic anhydride, glycerine, and ethylene glycol for comparison. Other three alkyds are “depolymerization product‐based alkyd resins” in which depolymerization products is used instead of ethylene glycol. Then, the physical and chemical surface coating properties and thermal behaviors of alkyd resins films were investigated comparatively. As a result, we concluded that aminolysis, aminoglycolysis, and simultaneous aminolysis‐hydrolysis products of waste PET are suitable for manufacturing both air drying and oven curing paint binder based on alkyd resins. The film prepared from alkyd resin based on simultaneous aminolysis‐hydrolysis product showed extremely good surface coating properties and thermal stability. POLYM. ENG. SCI., 54:2272–2281, 2014. © 2013 Society of Plastics Engineers     

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.     

Organic-Inorganic Hybrid Materials Based on the Incorporation of Polysilicic Acid Nanoparticle (PN) with Organic Polymers. 3. Shrinkage Characteristics in the Cure of Unsaturated Polyester Resin in the Presence of a Modified PN

The polysilicic acid nanoparticle (PN) was modified by the reaction of silanol group on its surface with silyl group (–Si(OR)₃) containing modifiers such as phenyltrimethoxylsilane (PTS), 2-(p-styryl)ethyltrimethoxylsilane (SETS), and 3-(trimethoxylsilyl)propyl methacrylate (TPMA), respectively, to afford modified PNs (M-PNs) including P-PN, S-PN, and T-PN. P-PN, S-PN and T-PN were mixed, respectively, with unsaturated polyester resin (UP) in styrene, UP/St, and then let homogeneous solutions cure at 150°C to produce transparent hybrid materials, UP/St/P-PN, UP/St/S-PN, and UP/St/T-PN. It was found that the M-PNs could not only act as low-profile additives (LPAs) to reduce the shrinkage of the hybrids during curing but also enhance their dynamic mechanical properties. The shrinking mechanism of the hybrids during curing and the interfacial force between M-PNs and UP/St matrix, which plays an important role in shrinking control and properties of hybrid, were studied in detail.     

Structure and properties of p-carboxysuccinanilic polyester resins

Polyester resins were prepared by the reaction of p-carboxysuccinanilic acid ethyl ester with ethylene glycol and 1,4-butenediol. Also, unsaturated polyester resins were prepared by the copolymerization of p-carboxysuccinanilic acid ethyl ester and maleic anhydride with ethylene glycol, 1,6-hexanediol, 1,4-butenediol, and 2-butyne-1,4-diol. All the polyester resins and the copolyesters have been characterized and were found to cure with styrene, except those prepared in the absence of maleic anhydride. The properties of the cured products in the form of films were determined. Infrared and nuclear magnetic resonance (NMR) spectroscopy were used for both qualitative and quantitative analyses of the polyester resins and their hydrolyzate products after curing with styrene.     

低收缩不饱和聚酯及其染色性研究

以甲基丙烯酸甲酯(MMA)和苯乙烯(St)为共聚单体,改变MMA和St的单体配比,用悬浮聚合方法合成了一系列共聚物,并以此作为低收缩添加剂(LPA),溶解于St中,加入到不饱和聚酯(UP)中进行固化反应。在此基础上,改变固化反应温度,LPA用量和种类,研究了LPA/UP体系固化后的体积收缩率、染色性能和力学性能。结果表明:MMA-St共聚物作为LPA,可以有效地降低UP固化后的体积收缩,并且保证了固化产物力学性能不降低和着色的均一性。     

Curable resins based on recycled poly(ethylene terephthalate) for coating applications

Poly(ethylene terephthalate) waste was depolymerised in the presence of diethylene- or tetraethylene glycol and manganese acetate as a catalyst. An epoxy resin was then prepared by the reaction of these oligomers with epichlorohydrin in presence of NaOH as a catalyst. The produced oligomers were condensed with maleic anhydride and ethylene glycol to produce unsaturated polyester. The chemical structures of the resulting epoxy and unsaturated polyester resins were confirmed by ¹HNMR. The vinyl ester resins were used as cross-linking agents for unsaturated polyester resin diluted with styrene, using free radical initiator and accelerator. The 2-amino ethyl piprazine was used as hardener for epoxy resins. The curing behaviour of the unsaturated polyester resin, vinyl ester resins and styrene was evaluated at different temperatures ranged from 25 to 55 °C to calculate the curing activation energy of the system. The cured epoxy and unsaturated polyester resins were evaluated in coating application of steel.     

Dynamic mechanical,mechanical and morphological properties of reactive thermotropic liquid crystalline polymer/unsaturated polyester/glass fibre hybrid composites

Abstract

Unsaturated polyester (UP) reinforced with self-synthesised reactive thermotropic liquid crystalline polymer (TLCP)–methacryloyl copolymer (LCMC) and glass fibre (GF), the hybrid composites of UP/GF/LCMC were prepared by moulding technology. The dynamic mechanical analysis indicated that storage modulus and glass transition temperature (T _g) of hybrid composites increased significantly because of the addition of LCMC. The effect of LCMC content on the mechanical properties of LCMC/UP/GF hybrid composites such as impact strength, specific strength and modulus and load–displacement relationship were also investigated through static mechanical tests. The mechanical properties of hybrid composites increased significantly because of the addition of LCMC. The crystal behaviour analysis of LCMC/UP blend was investigated by X-ray diffraction and polarising optical microscopy. The results showed that the crystal phase and texture structure of LCMC still existed in the blends after blending with UP. The morphology of fracture surfaces of hybrid composites containing different TLCP contents was observed by scanning electron microscopy. The present paper discussed the mechanism for the improvement of dynamic mechanical and mechanical properties.