Synthesis of urethane oils from palm oil and waste PET bottles

Waste PET bottles were depolymerized by propylene glycol at a weight ratio of PET to propylene glycol of 37.5 : 62.5, using zinc acetate as a catalyst. The glycolyzed product, consisting of oligomeric diols with a number–average molecular weight range of 240–1107, was obtained. It was further reacted with palm oil and tolylene diisocyanate to obtain urethane oils at hydroxyl to isocyanate ratios from 1 : 1 to 1 : 0.8, with and without methanol acting as a blocking agent. It was found that all the synthesized urethane oils were yellowish transparent liquids of low molecular weights. A lower isocyanate content or the presence of a blocking agent resulted in higher viscosity, higher molecular weight, and shorter drying time. The films of all synthesized urethane oils exhibited good hardness, excellent flexibility, and high impact strength. They also showed excellent water resistance, good acid resistance but only fair alkali resistance. Moreover, these prepared urethane oils had better adhesion compared with those of the commercial urethane oil. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

The usage of linseed oil‐based polyurethanes as a rheological modifier

Some oil‐based urethanes (urethane oils) were prepared from linseed oil, glycerol, and two types of diisocyanates, hexamethyle diisocyanate (HMDI) and 4,4′‐ diphenylmethane diisocyanate (MDI). These urethane oils were used as a rheological modifier in solvent‐based coatings. For this purpose the mixture prepared from urethane oil and alkyd resin (AR‐UO) was investigated in view of flow properties. Time dependence of AR‐UO was investigated by using the hysteresis loop method. None of the samples showed thixotropic flow behavior. The flow type was decided after calculation of the ratio of viscosity at low shear rate to viscosity at high shear rate. The results showed that HMDI‐based samples had the smallest viscosity ratio and increasing the amount of aromatic structure caused increasing shear thinning behavior. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1032–1035, 2005     

Preparation and properties of urethane alkyd based on a castor oil/jatropha oil mixture

Castor oil is the only major natural vegetable oil that contains a hydroxyl group and so it is widely used in many chemical industries, especially in the production of polyurethanes. In this work, castor oil was interesterified with jatropha oil and the product was subsequently reacted with toluene diisocyanate to obtain urethane alkyd. The prepared urethane alkyd was characterized and its properties were determined and compared with those of the conventional (glycerol/jatropha oil) and commercial urethane alkyds. The castor oil/jatropha oil-based urethane alkyd had a lower molecular weight and viscosity, a slightly lower hardness and greatly longer drying time than the conventional and commercial urethane alkyds, but otherwise the film properties were broadly similar, including being very flexible, with an excellent adhesion and high impact resistance. In addition, they also exhibited excellent resistance to water and acid.     

Study of film properties of some urethane oils

In this study, sunflower oil-based urethane oils were obtained from three kinds of isocyanate components: toluene diisocyanate (TDI), hexamethylene diisocyanate (HMDI) and poly(1,4-butandiol) toluene 2,4-diisocyanate (PBTDI) terminated prepolymer. The polymers were prepared at four different ratios of isocyanate component/oil. Sunflower and linseed oil alkyd resin samples were also prepared as the comparative samples. The results suggest that the viscosity and the film properties of urethane oils depend on the amount and type of isocyanate component. The increase in isocyanate content of the urethane oils caused high viscosity. In comparison with the samples having the same oil content, PBTDI-based samples showed the highest viscosity. Viscosity of the polymers can dramatically affect some film properties. For example, high polymer viscosity caused short drying time. In comparison of alkali and water resistances of urethane oils with those of alkyd resins, better results were obtained depending on the structure of the urethane oils. On the other hand, alkyd resins and TDI-based polymers exhibited the best hardness properties. Chemical Engineering Dept, Maslak 80626Istanbul, Turkey; email: guners@itu.edu.tr.     

Discussion of aqueous urethane acrylate oligomers with sulfoisophthalate on the antistatic hydrophilic finishing of different fabrics

In this study, PEG(SE) containing sulfonic acid group was produced by transesterification of dimethyl 5‐sulfoisophthalate sodium salt (SIP) with PEG. The reactive urethane acrylate oligomers were synthesized by using SE as soft segment, isophorone diisocyanate (IPDI) as hard segment, and hydroxyethyl methacrylate (HEMA) as blocking agent. Their solution properties and thermal properties were investigated. Dipping process was carried out on polyethylene terephthalate (PET) fabric, polyamide (nylon) fabric, and cotton fabric for hydrophilic finishing and the effects of processing condition on the fixation behavior and hydrophilic property of treated fabric have been discussed. The conclusions are as follows: the particle size of oligomer solutions are about 45–90 μm, surface tension of solutions are below 43 dyn/cm, and they have smaller contact angle than water. The particle size, particle variance, and streaming current reading decreased, but the surface tension and contact angle enhanced upon increasing PEG molecular weight. The melting point of oligomer is 38°C–52°C and the glass transition point is −18°C to −25°C. In comparison with the fabric finishing, the add‐on of PET fabric is the highest, followed by nylon, then cotton. The durability of treated cotton fabric is the highest, followed by PET, then nylon. The hydrophilicity is most stable for nylon fabric with PEG molecular weight of 2,000, and cotton and PET fabric with molecular weight of 1,000. POLYM. COMPOS., 29:45–57, 2008. © 2007 Society of Plastics Engineers     

Glycolyzed products from PET waste and their application in synthesis of polyurethane dispersions

Soft drinks poly(ethylene terephthalate) (PET) bottles were depolymerized by glycolysis with different molar ratio of glycol, such as propylene glycol (PG), triethylene glycol (TEG) and poly(ethylene glycol) (PEG 400), in the presence of a zinc acetate catalyst. These glycolyzed products were characterized by hydroxyl value (HV) determinations. The obtained glycolyzed products were reacted with isophorone diisocyanate (IPDI), dimethylol propionic acid (DMPA), as potential ionic center for water dispersibility, and mixed with ethylene diamine (EDA) as extender chain to prepare polyurethane dispersions. The PET glycolyzed products and polyurethane formation were characterized using Fourier transform infrared spectroscopy (FTIR). The molecular masses distribution of oligoester polyol and polyurethane dispersions were determined by using gel permeation chromatography (GPC). The effect of different PET/glycol molar ratio, on the physico-mechanical properties, such as hardness, adhesion test and gloss of polyurethane films were investigated. Thermal properties were investigated by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC).     

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.     

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     

Preparation and characterization of waterborne polyurethane containing PET waste/PPG as soft segment

Soft drinks poly(ethylene terephthalate) (PET) bottles were depolymerized by glycolysis using a 1 : 3 molar ratio of PET repeating unit to glycols like neopentyl glycol (NPG) and dipropylene glycol (DPG). Further, a series of waterborne polyurethanes (WPUs) was synthesized using pure polypropylene glycol (PPG), and glycolyzed oligoesters/PPG blends in different molar ratios as soft segment. Thermal property of WPU was tested by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Moreover, viscosity and particle size of WPU were also investigated. The results show that introduction of a certain amount of glycolyzed oligoester to soft segment makes the degree of hard‐soft domain microphase separation smaller, and can also improve thermal stability of WPU. Furthermore, WPUs synthesised from glycolyzed oligoesters and PPG blends possess larger particle size, better particle size distribution, relative lower and more stable viscosity. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42757.     

Organic–inorganic hybrid linseed oil‐based urethane oil wood coatings

To prepare alkoxysilane‐functionalized urethane oil (AFUO) using linseed oil, 3‐aminopropyltriethoxysilane (APTES) was first reacted with diisocyanate to obtain an NCO‐terminating oligomer. The reaction was continued by adding linseed oil glyceride to form an AFUO prepolymer. The auto‐oxidative drying coating was obtained after adding a metal dryer to the AFUO prepolymer. Urethane oil (UO) coating, as a control, was obtained by the same procedure as that for AFUO, but without containing alkoxysilane‐functional groups in the formation. Siloxane hybrid urethane oil (SHUO) wood coatings were prepared by mixing tetraethyl orthosilicate (TEOS) solutions, as an external crosslinking agent by sol–gel process, with the AFUO and UO coatings. We found that introducing of APTES into the molecular chains of the UO coating resulted in a film with superior impact and abrasion resistance, and it is the most efficient process to enhance the UO films. The addition of TEOS into AFUO coatings shortened the curing time and further improved the crosslinking density of the AFUO films; however, the physical properties like impact resistance, bending resistance, and gloss were even worse than AFUO films. Mixing of TEOS and UO coating also shorten the curing time and improved the heat resistance, lightfastness, and hardness of the UO coating. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44562.     

Reactive extrusion of recycled poly(ethylene terephthalate) with polycarbonate by addition of chain extender

Poly(ethylene terephthalate) (PET) resin is one of the most widely used engineering plastic with high performance, but the poor impact strength limits its applications for the notch sensitivity. In this research, toughened PET alloy was prepared by blending recycled PET with polycarbonate (PC) and MDI (methylenediphenyl diisocyanate). Intrinsic viscosity and melt viscosity measurements proved increase of the molecular weights of PET via chain‐extending reaction. FTIR and DMA results proved that some PET–PC copolymers were produced and the compatibility of PET phase and PC phase was improved. In addition, the reaction induced by MDI also affected the crystallization behaviors of PET, as observed from DSC results, and the crytallinity of PET decreased with the increase of MDI content. For all of these effects of MDI of increasing of molecular weight, improving of compatibility, and limiting the crystallization behaviors of PET/PC alloy, the notched‐impact strength was greatly improved from 17.3 to 70.5 kJ/m². © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2602–2607, 2007     

Structure–property relationship of blocked diisocyanates: synthesis of polyimides using imidazole‐blocked isocyanates

Imidazole, 2‐methylimidazole and benzimidazole‐blocked aromatic and aliphatic diisocyanates have been prepared and polymerized with pyromellitic dianhydride in the presence of a basic catalyst. The polymers are characterized with FTIR, ¹H NMR and ¹³C NMR spectroscopy and GPC, DSC and TGA. The structure–property relationship of blocked diisocyanates are discussed in terms of molecular weight of the polyimides obtained. Considering the blocking agent, GPC results show that the benzimidazole blocked adduct yields higher molecular weight polymer than the 2‐methylimidazole‐blocked adduct which, in turn, yields higher molecular weight polymer than the imidazole‐blocked adduct. Considering the structure of the isocyanate, the molecular weight of polymer increases from isophorone diisocyanate to hexamethylene diisocyanate and to toluene diisocyanate (TDI). DSC traces of the polymers derived from TDI show glass transitions (T_g) in the temperature range 152–180 °C and the values increase from the polymer based on imidazole‐blocked TDI to 2‐methylimidazole‐blocked TDI and to benzimidazole‐blocked TDI. © 2000 Society of Chemical Industry     

Chemoenzymatic synthesis of urethane oil based on special functional group oil

A two-step chemoenzymatic synthesis of urethane oil, consisting of a lipase-catalyzed transesterification of castor oil with n-butanol and a reaction of the resulting precursor (partial esters) with different diisocyanates, was studied. The effect of the type of lipase, alcohol chain length, solvent, and temperature in the transesterification step was examined. Urethane oils were characterized by IR, ¹H-NMR, and GPC techniques. The film properties were also tested. The composition varies with time in the transesterification step. Conversions were faster and more complete using lipozyme, where yields to 75% could be achieved. Enzyme activity increases with increase in the log P value of the solvent. The degree of transesterification and composition of the precursor have influence on the molecular weight and film properties of urethane oils. A good correlation was observed between the scratch resistance and monoglyceride percentage of the precursor of the respective urethane oils. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1451–1458, 1998     

Effect of structure modification on rheological properties of biodegradable poly(ester‐urethane)

Biodegradable lactic acid based poly(ester‐urethanes) (PEU) were polymerized and their structure and rheological properties were characterized. The polymerization process comprised two steps: lactic acid monomer was oligomerized to low molecular weight prepolymer, and this was then linked to high molecular weight PEU with chain extender, 1,6‐hexamethylene diisocyanate. The properties of PEU were modified by varying the amount of chain extender from 1.05:1 to 1.35:1 (NCO/OH ratio). The modification was mostly seen in the molecular weight distribution of the polymers, which was broadened from 2.2 to 3.5 as the amount of chain extender was increased. The telechelicity of the prepolymer was found to play an essential role in successful linking of the prepolymer units. In addition, the rheological properties of poly(ester‐urethane) were determined with capillary and dynamic rheometers. All PEU samples were pseudoplastic and broadening of their molecular weight distribution was accompanied by increased viscosity and complex viscosity at low shear rates and increased shear thinning. The temperature dependency of the measurement was pronounced. Rheological measurements also showed that PEU starts to degrade at 100°C and further rise in temperature increases the rate of degradation significantly.     

Effect of composition on the solution rheology of stearyl methacrylate‐co‐styrene‐co‐vinyl pyrrolidinone in paraffinic base oil

The rheological behavior of dilute and semi‐dilute solutions of stearyl methacrylate‐co‐styrene‐co‐vinyl pyrrolidinone copolymers (SMA‐S‐VP) was investigated over a wide range of temperatures (20–140°C) under steady shear (0.1–5000 s^?1) and dynamic conditions (0.01–500 rad/s). The solvent used was polyalpha olefin, PAO4 (C20‐C40 fraction), a fully synthetic paraffinic oil normally used as base oil for lubricant oil formulations. The investigation focuses on the effect of the polar comonomer segment content, of the copolymer, on the viscosity‐temperature relationship of the solution. This information provides insight into the effect of polymer microstructure on the viscosity index (VI) behavior of the lubricant. Copolymers with different ratios of stearyl methacrylate, styrene and vinyl pyrrolidinone were synthesized by solution radical polymerization. The microstructure and molecular weight of the copolymers were evaluated by nuclear magnetic resonance spectroscopy (NMR). The molecular weight and polydispersity of the polymers were determined using GPC. The polymer solutions exhibit non‐Newtonian behavior, which is more evident at lower temperatures and higher concentrations. The temperature‐concentration superposition principle developed by Ferry (1) was applied to steady shear data and the resulting master curve was fitted to the Carreau model. A modified Fedors equation for intrinsic viscosity calculation, at low and moderate polymer solution concentrations, was used. The results confirm that the viscosity index improver properties (VII) of the copolymer are superior when the VP content is low. The polymer‐solvent interactions and solvency power of PAO4 were analyzed using an Arrhenius expression. The results show that at low VP content, PAO4 is a better solvent for the copolymer. Polym. Eng. Sci. 44:736–748, 2004. © 2004 Society of Plastics Engineers.     

Effect of blocking agents on the shock absorbing properties of the films of polyurethane adhesives

Various 4,4-diphenylmethane diisocyanate (MDI0) based polyurethane adhesives have been developed using polyethylene glycols (PEG) of different moleclar weights. The formulations were modified using different blocking agents to inhibit the isocyanate-moisture reaction. Composites of poly(methyl methacrylate) sheets were developed in which these adhesives gave transparent films and their shattering characteristics were tested in a bullet firing machine developed here. The damaged area was measured and used to characterize the adhesive strength. The molecular weight of the soft segment (diol) and the nature of the blocking agent both were found to affect drastically the urethane film properties.     

Poly(ether urethane)s from aromatic diisocyanates based on lignin‐derived phenolic acids

A series of new bio‐based aromatic diisocyanates, namely bis(4‐isocyanato‐2‐methoxyphenoxy)alkane and bis(4‐isocyanato‐2,6‐dimethoxyphenoxy)alkane, were synthesized starting from lignin‐derived phenolic acids, namely vanillic acid and syringic acid, via the Curtius rearrangement. The diisocyanates were employed to synthesize poly(ether urethane)s by reacting them with potentially bio‐based aliphatic diols, namely 1,10‐decanediol and 1,12‐dodecanediol. The chemical structures of diisocyanates and poly(ether urethane)s were confirmed using Fourier transform infrared, ¹H NMR and ¹³C NMR spectroscopy. Inherent viscosities and number‐average molecular weights of the poly(ether urethane)s were in the ranges 0.58–0.68 dL g^?1 and 32 100–58 500 g mol^?1, respectively, indicating the formation of reasonably high molecular weight polymers. The poly(ether urethane)s exhibited 10% weight loss in the temperature range 304–308 °C. The glass transition temperatures of the poly(ether urethane)s were in the range 49–74 °C and were dependent both on the number of methylene units in the diols and on the number of methoxy substituents on the aromatic rings of the diisocyanate component. © 2017 Society of Chemical Industry     

Unsaturated polyesters from PET waste: Kinetics of polycondensation

PET waste was glycolyzed by propylene glycol at different weight ratios. The glycolyzed products were analyzed for hydroxyl value, number average molecular weight, and the amount of free glycol. The glycolyzed products were reacted with maleic anhydride at a hydroxyl to carboxyl ratio of 1.1. The control resin was a general purpose unsaturated polyester prepared by reacting phthalic anhydride, maleic anhydride, and propylene glycol. The heating schedule of the polyesterification was comparable to that normally employed in the industrial process, with two isothermal plateau of 3–4 h at 180 and 200°C. The rate of reactions and rate constants were determined separately at 180 and 200°C. The kinetics of the PET-based unsaturated polyesters was compared with that of the general purpose resin. It was found that the PET waste could be depolymerized by propylene glycol to a molecular weight range of 276–480. The polyesterification reactions followed a third-order kinetics. The rates of polyesterification of PET based systems were higher than that of the general purpose resin. PET-based systems were higher than that of the general purpose resin. PET-based systems took about 10 h to reach an acid value of 32 mg KOH/g whereas the general purpose resin took about 25 h to reach the same acid value.     

Synthesis and coating characteristics of novel calcium‐containing poly(urethane ethers)

Calcium salt of mono(hydroxypentyl)phthalate [Ca(HPP)₂] was synthesized by the reaction of 1,5‐pentanediol, phthalic anhydride, and calcium acetate. Calcium‐containing poly(urethane ethers) (PUEs) were synthesized by the reaction of hexamethylene diisocyanate (HMDI) or toluylene 2,4‐diisocyanate (TDI) with a mixture of Ca(HPP)₂ and poly(ethylene glycol) (PEG₃₀₀ or PEG₄₀₀) with di‐n‐butyltin dilaurate as a catalyst. We synthesized a series of calcium‐containing PUEs with different compositions by taking the molar ratio of Ca(HPP)₂ : PEG₃₀₀ or PEG₄₀₀ : diisocyanate (HMDI or TDI) as 2 : 2 : 4, 3 : 1 : 4, and 1 : 3 : 4 to study the coating properties of the PUEs. Blank PUEs without a calcium‐containing ionic diol were also prepared by the reaction of PEG₃₀₀ or PEG₄₀₀ with HMDI or TDI. The PUEs were well characterized by fourier transform infrared spectroscopy, ¹HNMR, ^?13C‐NMR, solid‐state cross‐polarity/magic‐angle spinning ¹³C‐NMR, viscosity, solubility, and X‐ray diffraction studies. The thermal properties of the polymers were also studied with thermogravimetric analysis and differential scanning calorimetry. The PUEs were applied as a top coat on acrylic‐coated leather, and their physicomechanical properties were also studied. The coating properties of PUEs, including tensile strength, elongation at break, tear strength, water vapor permeability, flexing endurance, cold crack resistance, abrasion resistance, color fastness, and adhesive strength, were better than the standard values. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 710–721, 2004     

Mechanical properties of poly(ethylene terephthalate) modified with functionalized polymers

This study examined the effect of blending poly(ethylene terephthalate) (PET) with 5% of a functionalized polymer. The blends were characterized by particle size and size distribution, unnotched tensile behavior, toughness, and notch sensitivity. The improved properties of blends that incorporated a functionalized elastomer were consistent with in situ formation of a graft copolymer by reaction with PET end groups. Triblock copolymers were examined that had styrene end blocks and an ethylene/butylene midblock (SEBS) with grafted maleic anhydride. The present study extended previous investigations that focused on level of grafting to examine the effects of component molecular weight and PET hydroxyl‐to‐carboxyl end‐group ratio. Increasing the molecular weight of the SEBS and decreasing the hydroxyl‐to‐carboxyl ratio of the PET increased the effectiveness of the SEBS. In addition, a mix of an unfunctionalized SEBS with a functionalized SEBS was more effective than a single SEBS with the same total anhydride content. The same elastomers were the most effective for modifying a lower molecular weight PET (intrinsic viscosity 0.73) and a higher molecular weight PET (intrinsic viscosity 0.95). Some functionalized polypropylenes included in the study did not enhance the properties of PET. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 203–219, 1999