Polybutylene terephthalate modified with dimer acid methyl ester derived from fatty acid methyl esters and its use as a hot-melt adhesive

A series of polyester copolymers was synthesized via melt polycondensation of dimethyl terephthalate (DMT), dimethyl isophthalate (DMI), and 1,4-butanediol (BDO) with dimer acid methyl ester (DAME) monomers, previously prepared by the Diels–Alder reaction of fatty acid methyl esters (FAMEs). We obtained copolymers with the desired composition and a high molar mass characterized by ¹H NMR, FT-IR, and SEC. The relationship among the composition, thermal behavior, mechanical properties, and adhesion properties of these copolymers was examined, demonstrating that the DAME-modified copolymers could be substituted for HMA applications and are comparable to petroleum-based commercial products. As a result, these polyesters could offer improved sustainability and performance and may be good candidates for hot-melt adhesive materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48474.     

Preparation of waterborne elastic polyesters by chain extension with isophorone diisocyanate as a chain extender

Isophorone diisocyanate was used as a chain extender to coupling the soft segment water-borne polyester with the hard segment water-borne polyester, to overcome the disadvantages of low molar mass and poor mechanical properties of waterborne sulfonate-containing polyesters. The molecular structure of the extended polyester was confirmed by FTIR and ¹H NMR, and the increased molar mass of the resultant was characterized by SEC. The extended products could be dispersed in water with the emulsion particle size less than 50 nm in diameter, slightly larger than that of precursors of soft- and hard-segment polyesters. The emulsion viscosity of polyesters after the chain extension was lower when the emulsion concentration was not larger than 25 wt%, which is conducive to the spraying application of the polyester for coating. DSC analysis indicated that the polyester after chain extension had two different glass temperatures, suggesting that the polyester bulk had a microphase separation structure. The mechanical performance of the coupled polyester manifested an obviously improved elongation at break and had a feature of higher elastic recovery rate. The results of this study indicate that the chain extension is an effective method to increase the molar mass and improve mechanical properties of waterborne polyesters. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48453.     

Grafting of natural rubber for preparation of natural rubber/unsaturated polyester resin miscible blends

Graft copolymers of natural rubber and polystyrene were synthesized by free‐radical grafting of styrene monomer onto natural rubber in latex form. The obtained graft copolymers and unsaturated polyester (UPE) resin were mixed and cast at room temperature using methyl ethyl ketone peroxide as an initiator and Co‐octoate as an accelerator. The samples prepared from ungrafted natural rubbers exhibited the aggregation of the rubber component, whereas the samples prepared from grafted natural rubbers showed good dispersion of the rubber component in a glassy matrix of UPE resin. It was found that the amount of polystyrene grafted onto natural rubber and the graft copolymer content in polymer blend significantly affect the mechanical properties of the blend samples. An increase in the amount of hard and brittle polystyrene in glassy matrix of UPE resin overshadowed the impact‐absorbing ability of the rubber component, causing the impact strength of the blend samples to be lower than that of pure UPE resin. On the other hand, an increase in easily elongated uncrosslinked rubber molecules, as the graft copolymer content in blend samples increased, resulted in a decrease in their flexural strength. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1496–1503, 2004     

Synthesis of poly(styrene-co-isopropenyl acetate) -g-polyisobutylene graft copolymers via combination of radical polymerization with cationic polymerization

Random copolymers of poly(styrene-co-isopropenyl acetate) (SIPA) with an average number of 9 initiating sites per chain were synthesized by free radical copolymerization of styrene with a small amount of isopropenyl acetate using 2,2′-azo-bis-(isobutyronitrile) as an initiator at 70 °C. SIPA copolymer could be further used as macroinitiator for the grafting cationic polymerization of isobutylene (IB) from SIPA chain in CH₂Cl₂ at ?40 °C to produce graft copolymers of SIPA-g-PIB. The effect of SIPA concentration ([SIPA]), TiCl₄ concentration ([TiCl₄]) and IB concentration ([IB]) on initiation efficiency of macroinitiator, grafting efficiency of initiating sites, average length of PIB branches of the resulting graft copolymers were investigated. It can be found that almost all of the initiating sites of IPAc units on SIPA chains were active for the cationic polymerization of IB and both initiation efficiency and grafting efficiency were close to 100% at sufficient molar ratio of TiCl₄/IPAc. This synthetic route presents quantitative grafting efficiency and possibility to control length of PIB branches. The graft copolymers of SIPA-g-PIB with average 9-branched PIB chains having terminal functional tert-chlorine groups could be successfully obtained. The average molecular weight of PIB branches in SIPA-g-PIB graft copolymers could be mediated from 3900 to 47,300 g mol^?1 by changing the ratios of macroinitiator to monomer and concentration of TiCl₄.     

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     

Block copolymers of unsaturated polyesters and functional elastomers

Block copolymers of unsaturated polyester were prepared by condensation polymerization of hydroxyl or carboxyl terminated liquid rubbers with maleic anhydride, phthalic anhydride, and propylene glycol. The condensate obtained was mixed with styrene monomer to get an unsaturated polyester resin formulation. In this study, copolymers of unsaturated polyesters with hydroxy terminated polybutadiene, carboxy terminated nitrile rubber, and hydroxy terminated natural rubber were prepared. Mechanical properties such as tensile strength, tensile modulus, elongation at break, toughness, impact strength, surface hardness, abrasion resistance, and water absorption were evaluated after the resin was cured in appropriate molds for comparison with the control resin. The fracture toughness and impact resistance of CTBN‐modified unsaturated polyester show substantial improvement by this copolymerization without seriously affecting any other property. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1956–1964, 2004     

Synthesis and characterization of brominated polyester composites

Two unsaturated polyesters containing a halogen (bromine) in the backbone of the polymer chain were synthesized and compared with a halogen‐free polyester. The bromine content was measured by elemental analysis. The chemical structures of the polyesters were characterized by means of IR and ¹H‐NMR spectroscopies. Feldspar was used as the filler to form the polyester composites. The effects of the halogen substituents, filler concentration, and crosslinking monomers and comonomers on the electrical and mechanical properties of the polyester composites were studied. The flammability was also investigated. The styrenated polyesters and their composites achieved fire resistance and good mechanical and electrical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1356–1365, 2006     

Ionic polymers with tunable liquid‐crystalline properties

Side‐chain polyesters were synthesized from N‐octyl‐, N‐dodecyl‐ or N‐hexadecyl‐diethanolamine and succinic acid anhydride. These polyesters were then transformed into polyester hydrochlorides by protonation of the amino groups using different amounts of HCl (20–100 mol%). Above 60 mol% the reaction is not quantitative and a degree of protonation of up to 88% is obtained. The structures of the synthesized polyesters and their hydrochlorides were determined by ¹H nuclear magnetic resonance spectroscopy. The thermal properties of the synthesized polyesters and their hydrochlorides were also studied using differential scanning calorimetry in relation to the side‐chain length and the degree of polyester protonation. The polyester with octyl side chains and its hydrochlorides were amorphous liquids at room temperature, while the polyester and polyester hydrochlorides with hexadecyl side chains formed a smectic crystalline phase, S_mB, or its tilted analogues. The polyester with a dodecyl side chain was also an amorphous liquid at room temperature, while its hydrochlorides with various degrees of protonation were smectic liquid crystals, as determined by X‐ray diffraction. By simply varying the degree of protonation the liquid crystal isotropization temperature was increased from 32 °C to 82 °C. Copyright © 2011 Society of Chemical Industry     

Polyesters from renewable resources: Preparation and characterization

Polyesters were synthesized with monoglycerides prepared from rubber seed oil, a renewable resource. Monoglycerides were obtained by an alcoholysis method from the oil, which was neat or modified by treatments with different amounts of maleic anhydride at 230°C. The polyester resins were subsequently prepared by the condensation polymerization of the monoglycerides with phthalic anhydride. The monoglycerides and resins were characterized by spectroscopic analysis and measurements of the physicochemical properties. The chemical resistance of the polyesters was also studied. The results revealed that the polyesters prepared from the modified monoglycerides possessed better properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3748–3755, 2006     

Synthesis of Water-Soluble Polyesters Containing Carboxy-Functional Groups in the Polymers Chain and Study of Their Metal Complexes

The diethylenetriaminepentaacetic acid bisanhydride (DTPABA) was synthesized from diethylenetriaminepentaacetic acid (DTPA) and was further subjected to polyaddition with diols like polyethylene glycols (PEG) of different molar masses to form the polyesters. The polyesters synthesized were soluble in water as well as organic solvents and show better complexing ability than their monomer. The metal complexes of polyesters were synthesized by the reaction of water-soluble polyesters with copper acetate. The synthesized water-soluble polyester and their copper complexes were characterized by their melting points, elemental analysis, UV–Vis spectroscopy, viscometry, FTIR, ¹H NMR, SEM, AFM, XRD data, thermal stability of the compounds synthesized was studied by TG-DTA analysis. The antibacterial activity of synthesized polyesters has been studied against the bacterial species Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis.     

Synthesis and properties of polydiacetylene-containing polyesters

A series of diacetylene-containing polyesters with number-average molar masses (GPC) in the range 900–4200 g mol⁻¹ were prepared from terephthaloyl chloride and hexa-2,4-diyne-1,6-diol using benzoyl chloride as a monofunctional reactant for control of molar mass. Degrees of crystallinity were estimated from WAXD to be up to 29%. Correlations between molar mass, melting behaviour, degree of crystallinity and thermal cross-polymerisation of diacetylene-containing polyesters have been established using hot-stage microscopy, DSC and resonance Raman spectroscopy. The polyester with M̄_n of 1264 g mol⁻¹ gave the best balance between processability and the ability to cross-polymerise efficiently. Its degree of crystallinity before cross-polymerisation was estimated from WAXD measurments to be 24%, a value coincident with the percentage conversion of diacetylene units to polydiacetylene chains measured by ¹³C solid-state NMR. The optimum conditions for compression moulding the polyester to produce a material with a strong Raman spectrum involved heating under vacuum at 120°C for 6h after an initial 3 h heat-up period. The material thus produced gave an intense Raman CC stretching band, which upon tensile deformation shifted linearly with strain to lower wavenumber by 12.0 cm⁻¹ %⁻¹. The potential use of the diacetylene-containing polyesters in the preparation of model blends for use in quantitative micromechanics studies of stress transfer between phases is briefly discussed.     

NMR and MALDI-TOF MS study of side reactions in hyperbranched polyesters based on 2,2-bis(hydroxymethyl)propanoic acid

Hyperbranched polyesters of 2,2-bis(hydroxymethyl)propanoic acid (BMPA) with various molar ratios of tetra(hydroxymethyl)methane (PE) core molecule were characterized by NMR spectroscopy and MALDI-TOF mass spectrometry. In all polyesters, the formation of ether groups was observed. The extent of etherification increased with increasing PE content. This was assigned to a higher reactivity of PE towards etherification than BMPA. Intra- and intermolecular etherifications and intramolecular esterifications were detected by MALDI-TOF MS on the core molecule-containing polyesters, resulting in the formation of cycle-containing hyperbranched molecules. The ratio of cycle-containing molecules reached 50% at high reaction time for the polyester without core molecule, but was much lower for the polyesters containing a core molecule. As a consequence of these side reactions, the control of hyperbranched polyester molar mass by varying the core molecule (chain limiter) molar ratio is much more difficult than for linear polyesters.     

Synthesis and characterization of telechelic phosphine oxide polyesters and cobalt(II) chloride complexes

A monofunctional phosphine oxide containing endcapping reagent, 4-carboxyphenyl biphenyl phosphine oxide, was synthesized for the preparation of telechelic polyester oligomers. The chemical structure of the endcapping reagent was verified using NMR spectroscopy, mass spectroscopy, and elemental analysis. Phosphine oxide telechelic polyesters were prepared for the first time via copolymerization of a low molar mass polyester oligomer precursor and the phosphine oxide endcapping reagent in the melt state. The quantitative incorporation of telechelic phosphine oxide functionality was confirmed using ¹H NMR spectroscopy and elemental analysis. The corresponding complexes of phosphine oxide terminated polyesters and cobalt(II) chloride were prepared via charging the cobalt salt at the onset of melt polymerization. ³¹P {¹H} NMR spectroscopy, FT-IR spectroscopy, and UV-vis spectroscopy indicated that the cobalt(II) ion preferentially coordinated with the phosphine oxide end groups. The complexes exhibited higher melt viscosity than their salt-free analogues due to the formation of coordinated polymers. The presence of the telechelic phosphine oxide end groups also aided in the homogeneous dispersion of the cobalt salt in a poly(ethylene terephthalate) (PET) matrix.     

Synthesis and properties of novel star-shaped polyesters based on l-lactide and castor oil

The topology of biodegradable polyesters can be adjusted by incorporating multifunctional polyols into the polyester backbone to obtain branched polymers. The aim of this study was to prepare the biodegradable-branched polyester polyols based on l-lactide and castor oil using the trifluoromethanesulfonic acid as a catalyst. FTIR and ¹H NMR spectroscopy measurements were used to estimate the molecular structure of the novel materials. The polyester polyol was synthesized by ‘‘core-first” method which involves a polymerization of l-lactide by using a castor oil as multifunctional initiator. Molar masses estimated by gel permeation chromatography and vapor pressure osmometry were in good correlation with calculated values based on hydroxyl number of obtained polymers. DSC measurements confirmed high crystallinity degree of the synthesized material. It was assessed that the molar masses of obtained polymers-influenced glass transition temperature significantly. The thermal stability was investigated by TG analysis, and the results have shown the dependence of weight loss on the arm length of the star-shaped polyesters. The thermal stability of star-shaped polyesters significantly decreased with degradation of polyester polyol obtained in acid solution.     

Effect of γ-irradiation on chlorendic acid based unsaturated polyesters

The effect of gamma ray irradiation on chlorendic acid based unsaturated polyesters was studied. Four different types of unsaturated polyesters, made by varying the molar ratios of chlorendic acid to isophthalie acid were irradiated with a Co⁶⁰ qource. After irradiation, the chlorine content decreases rapidly as the isophthalate content in the polyester chain increases. As the chlorendle acid content increases, the change in acid value after irradiation decreases. The increase in intrinsic viscosity is quite marked in high isophthalate containing polyesters after gamma ray irradiation and there is a noticeable decrease in intrinsic viscosity after gamma irradiation of high chlorendic acid containing polyesters. The effect of gamma irradiation on the percentage of cis and trans forms of these polyesters was studied with the help of infrared spectra. It appears that as the chlorendic acid content increases, on gamma irradiation conversion from trans unsaturation to cis unsaturation increases rapidly.     

Controllable Synthesis of Submicrometer Core–Shell Modifier and Its Effect on Toughening Polypheylene Ether/Polystyrene Blends

Core–shell polybutadiene-graft-polystyrene (PB-g-PS) graft copolymers with different ratios of PB to PS are synthesized by emulsion polymerization. Further, the PB-g-PS copolymers are blended with polypheylene ether (PPE) and PS to prepare PPE/PS/PB-g-PS blends. The effects of PB-g-PS copolymer structure and matrix composition on the morphological, mechanical properties, and deformation mechanism of the blends are studied. The results show that the synthesized submicrometer-sized PB-g-PS copolymer has an excellent toughening efficiency, both the copolymer and PS are introduced into PPE resin to produce a ternary blend which is combined with high toughness and processing properties. The optimum toughening effect on PPE/PS matrix is observed at the core–shell weight ratio of 70/30 in PB-g-PS copolymer, and the impact strength of the blends increased from 101 to 550 J m⁻¹. In addition, the dispersion pattern of rubber particles in the matrix gradually changes from uniform dispersion to aggregation as the core–shell ratio of PB-g-PS copolymers increases. On the other hand, with the increase of PPE content, the dispersion of rubber particles in PPE/PS matrix is improved, and the deformation mechanism is changed from cracking to a combination of crazing and shear yielding, which can lead to absorb more energy to achieve better toughness.     

Bio‐based diblock copolymers prepared from poly(lactic acid) and natural rubber

New bio‐based diblock copolymers were synthesized from poly(lactic acid) (PLA) and natural rubber (NR). NR polymer chains were modified to obtain hydroxyl telechelic natural rubber oligomers (HTNR). Condensation polymerization between PLA and HTNR was performed at 110°C during 24 or 48 h. The molecular weight of PLA and HTNR and the molar ratio PLA : HTNR were varied. The new ester linkage in the diblock copolymers was determined by ¹H‐NMR. The molecular weight of the diblock copolymers determined from SEC agreed with that expected from calculation. The thermal behavior and degradation temperature were determined by DSC and TGA, respectively. The diblock copolymers were used as a toughening agent of PLA and as a compatibilizer of the PLA/NR blend. PLA blended with the diblock copolymer showed higher impact strength, which was comparable to the one of a PLA/NR blend. The former blend showed smaller dispersed particles as showed by SEM images, indicating the increase in miscibility in the blend due to the PLA block. The compatibilization was effective in the blends containing ～10 wt % of rubber. At a higher rubber content (>10 wt %), coalescence of the NR and diblock copolymer was responsible of the larger rubber diameter in the blends, which causes a decrease of the impact strength. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41426.     

Mechanical properties of epoxy resin/hydroxyl‐terminated polyester blends: effect of two‐phase structure

In this paper, the effect of two‐phase structure on the mechanism of rubber‐toughening of epoxy resins was studied. Three types of hydroxyl‐terminated polyesters with different molecular weights were synthesized in order to modify epoxy resins to obtain single‐phase (P‐1), critical phase separation (P‐2) and two‐phase (P‐3) structures. The results of dynamical mechanical analysis and scanning electron microscopy distinguished the dissolved and phase‐separated polyesters in the epoxy matrix. The P‐1 system showed the highest dissolved content of polyester in the epoxy matrix, while the P‐3 system exhibited the lowest content. Both dissolved and phase‐separated polyesters proved to be capable of increasing the toughness of modified epoxy resins. The phase‐separated polyester was found to contribute much more to the improvement of toughness. Copyright © 2005 Society of Chemical Industry     

Synthesis and properties of amphiphilic copolymers of butyl acrylate and methyl methacrylate with uniform polyoxyethylene grafts

Amphiphilic copolymers of butyl acrylate (BA) and methyl methacrylate (MMA) with uniform polyoxyethylene (PEO) grafts were synthesized by the copolymerization of BA and MMA with a methacrylate‐terminated PEO macromer in benzene with azobisisobutyronitrile as an initiator. The effects of various copolymerization conditions on the grafting efficiency and molecular weight of the copolymers, as well as the effect of the copolymerization time on the conversions of the macromer and the monomers, were reported. The copolymers, with uniform PEO grafts, were purified by successive extractions with water and ether/acetone (3/7) to remove unreacted macromer and ungrafted copolymers of MMA and BA, respectively. The purified graft copolymers were characterized with IR, ¹H‐NMR, membrane osmometry, gel permeation chromatography, and differential scanning calorimetry. The highest grafting efficiency was about 90%, and molecular weight of the copolymers varied around 10⁵. The average grafting number of the copolymer was about 10. A study of the crystalline properties, emulsifying properties, phase‐transfer catalytic ability, and mechanical properties of the graft copolymers showed that the emulsifying volume decreased with the increasing molecular weight of the PEO grafts but increased with the PEO content. The conversion of potassium phenolate in the Williamson solid–liquid reaction obviously increased with an increasing PEO content of the graft copolymers. The crystallinity of the graft copolymers increased with the PEO content of the graft copolymers or the molecular weight of the macromer used. The copolymers, prepared under certain conditions, behaved as thermoplastic elastomers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2982–2988, 2003     

以聚C_(9-13)二元酸乙二醇酯为基础的粘接型聚氨酯树脂的合成与研究

:采用菜油脂肪酸氧化裂解所得 C9 13混合二元酸与乙二醇缩聚 ,制备了线型聚酯 ,以此为基础合成了全热塑的端羟基聚氨酯树脂。聚酯的分子量、聚酯与扩链剂、二异氰酸酯的配比对聚氨酯的溶解性、粘接强度均有显著影响。用分子量 30 0 0的聚C9 13二元酸乙二醇酯 ,按聚酯∶扩链剂∶二异氰酸酯 =1∶ 1∶ 2 ( mol比 )的投料 ,制得的聚氨酯树脂具有最佳的综合性能 ,适于多种鞋材的粘合。