Synthesis Of Bio-based Polyurethanes Research Articles

Synthesis of novel bio-based and degradable polyurethanes using lignin oligomers

Bio-based and degradable materials were proposed to challenge the major problem of plastic disposal in the environment. In this context, polyurethane production was re-evaluated, encouraging the search for replacing both petroleum components and highly toxic species. A novel synthesis route is explored in this work, aimed to produce degradable lignin-based polyurethanes. Oligomers from steam-exploded lignin were extracted and used with ε-caprolactone (ε-CL) to generate a fully bio-based pre-polymer (oligo-grafted-poly(ε-CL)), exploiting ring-opening polymerization. We have demonstrated that tuning the main reaction parameters, such as ε-CL:oligomer and catalyst:ε-CL mass ratios, and reaction time, it is possible to obtain different pre-polymers enabling the synthesis of bio-based polyurethanes with variable physicochemical properties. In particular, the oligomeric content modulates the thermal and mechanical properties of the polymer (melting point range: 54–62 °C; Young modulus range: 3–7 kPa) and enhances the degradability (up to 13 % wt, in acid environment), highlighting the potential of the material for possible applications.

Engineering RuBisCO-based shunt for improved cadaverine production in Escherichia coli

The process of biological fermentation is often accompanied by the release of CO2, resulting in low yield and environmental pollution. Refixing CO2 to the product synthesis pathway is an attractive approach to improve the product yield. Cadaverine is an important diamine used for the synthesis of bio-based polyurethane or polyamide. Here, aiming to increase its final production, a RuBisCO-based shunt consisting of the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and phosphoribulate kinase (PRK) was expressed in cadaverine-producing E. coli. This shunt was calculated capable of increasing the maximum theoretical cadaverine yield based on flux model analysis. When a functional RuBisCO-based shunt was established and optimized in E. coli, the cadaverine production and yield of the final engineered strain reached the highest level, which were 84.1 g/L and 0.37 g/g Glucose, respectively. Thus, the design of in situ CO2 fixation provides a green and efficient industrial production process.

Sunflower oil-based polyurethane/graphene composite: Synthesis and properties

Polyurethane/graphene composites have attracted significant attention featuring their wide applications in automotive interiors, coatings, and leather parts to bioengineering. This research focuses on the facile synthesis of biobased polyurethane (PU) by employing sunflower oil as a renewable resource. The synthesized biobased PU was reinforced with graphene nanoplatelets (GNP) and graphene nanoribbons (GNR) to fabricate composite films by solution-casting technique. By changing the filler content (0.01-0.05 wt%), a series of composite films were prepared. The addition of graphene derivatives to the PU matrix improved the mechanical, thermal, and surface properties of the composites compared to the pristine PU film. The incorporation of GNR and GNP fillers enhanced the storage modulus of polymeric film, as for neat PU, was noted maximum at 892 MPa which increased and noticed a maximum of 1121 MPa and 1487 MPa for 0.02 wt % GNP/PU and GNR/PU composite films, respectively. The tensile strength was obtained at 35 MPa and 14 MPa for 0.02 wt % GNP/PU and 0.01 wt % GNR/PU, as compared to 9.45 MPa for the pure PU film. The morphological studies by atomic force microscopy showed a good distribution of GNR and GNP fillers within the polyurethane matrix. The GNP/PU and GNR/PU composite films displayed excellent chemical resistance to different solvents. This work put forward a great utilization of renewable sunflower oil and graphene derivatives to fabricate PU composites with improved properties for potential applications.

Lignin-based bisguaiacol diisocyanate: a green route for the synthesis of biobased polyurethanes

The synthesis of aromatic diisocyanate derived from lignocellulosic raw materials, namely guaiacol and vanillyl alcohol, through phosgene-free route offers the prospect of greener approaches for isocyanate production and the polyurethane industry.

Effects of Isocyanate-to-Polyols (NCO/OH) Ratio on Bio-based Polyurethane Film from Palm Kernel Oil based Monoester Polyols (PKO-p) for Polymer Electrolytes Application

This study investigated the synthesis of bio-based polyurethane (PU) film from palm kernel oil-based polyols (PKO-p) at four different isocyanate-to-polyols (NCO/OH) ratios comprising 100/100, 100/150, 100/200, and 100/250. The PU film was prepared by mixing 2,4-methylene diphenyl diisocyanate (MDI) and PKO-p in acetone using the pre-polymerization technique under a nitrogen atmosphere at room temperature. The effect of the NCO/OH ratio on the properties of the PU films was analyzed through infra-red spectroscopy, molecular weight distribution, thermal behavior, and impedance spectroscopy. According to the infra-red spectroscopic analysis, the formation of urethane linkages (–NHCOO–) after the polymerization was indicated through the disappearance of isocyanate (N=C=O) peak and the appearances of secondary amine, carbonyl, carbamate, ether, and ester groups in the PU chain. In addition, the Gel Permeation Chromatography (GPC) showed that the weight of average molecular weight (MW) increased with increasing NCO/OH ratio up to 1.23 × 106 g mol-1. Nevertheless, higher content of PKO-p resulted in a low crosslink PU (4 % crosslink) and poor physical properties such as soft, sticky, and easy to tear due to the non-hydrogen bonded urethane. Moreover, the glass-transition temperature (Tg) reduced from 67 °C to 30 °C with the increase in PKO-p content. Despite all samples experienced the same thermal stability at 187 °C, a significant difference was observed in the mass loss of NCO/OH ratios. The highest thermal degradation was found at (100/200) NCO/OH ratio with Tmax = 444 °C. Furthermore, the piezoelectricity characteristic of pristine PU recorded the bulk resistant of up to ~107 – 105 Ω which reduced further after the presence of lithium iodide (LiI) salts as the charge carrier with the calculated ionic conductivity around 10-5 S cm-1. Thus, this study demonstrated the promising physicochemical properties of PU film from PKO-p for polymer electrolyte application.

Recyclable, self-healing itaconic acid-based polyurethane networks with dynamic boronic ester bonds for recoverable adhesion application

Currently, synthesis of biobased polyurethane (PU) networks with recyclability, self-healing, as well as robust mechanical and adhesion properties still remain a challenge. Herein, a series of robust itaconic acid-based polyurethane networks (IAPU) with dynamic boronic ester bonds are fabricated and fully characterized by FTIR and DMA. All the obtained IAPU networks display high thermostability with an initial decomposition temperature around ∼270 °C. The activation energy and typology transition temperature of the IAPU-80 are 71.9 kJ mol−1 and -25.8 °C, respectively. The IAPU-80 shows low relaxation times from 169 to 125 s at moderate temperature from 60 to 65 °C, respectively, as well as excellent mechanical properties (tensile strength = 15.6 MPa, elongation at break = 70.4%, toughness = 12.6 MJ m−3). The IAPU-80 possess outstanding scratch self-healing ability (scratch disappear after heating at 120 °C for 10 min) and reprocessability (without distinct decrement of the tensile strength after twice recycling). Remarkably, the IAPU-80 bonded wood sample exhibits a high recoverable adhesion strength (∼8.2 MPa), after reused for three times. Therefore, the self-healing and malleable IAPUs with recoverable adhesion performance are obtained by incorporating dynamic boronic ester bonds into itaconic acid-based polyurethane networks. Present work describes a green and facile way to prepare sustainable PU networks with multiple functionalities for wide applications.

Cellulose as a polyol in the synthesis of bio-based polyurethanes with simultaneous film formation

Cellulose as a polyol in the synthesis of bio-based polyurethanes with simultaneous film formation

Synthesis of diols from jojoba oil via rhodium-catalyzed reductive hydroformylation: a smart way to access biobased polyurethanes

Diol was synthesised from Jojoba oil ester by a recyclable catalytic system and was used for biobased polyurethane synthesis.

Blending of cyclic carbonate based on soybean oil and glycerol: a non-isocyanate approach towards the synthesis of polyurethane with high performance

This work demonstrates the synthesis of bio-based polyurethane from soybean oil and glycerol derived highly branched structure via non-isocyanate route. The soybean oil based cyclic carbonates were synthesized by coupling of CO2 with epoxidized soybean oil. In the second step, glycerol derived highly branched cyclic carbonate was synthesized from diglycidal ether of bisphenol A (DGEBA) and CO2. The structure of prepared monomer was confirmed from FT-IR, 1H and 13C NMR spectra. Then a series of non-isocyanate polyurethanes (NIPUs) were synthesized. They exhibited satisfactory mechanical properties (Tensile strength = 10.1 MPa) and thermal stability (283 °C). These results indicate the prospect of this eco-friendly approach for preparing renewable NIPU without the use of isocyanate.

Efficient Synthesis of Cyclic Carbonates from Unsaturated Acids and Carbon Dioxide and their Application in the Synthesis of Biobased Polyurethanes.

Bio-derived furan- and diacid-derived cyclic carbonates have been synthesized in high yields from terminal epoxides and CO2 . Furthermore, four highly substituted terpene-derived cyclic carbonates were isolated in good yields with excellent diastereoselectivity in some cases. Eleven new cyclic carbonates derived from 10-undecenoic acid under mild reaction conditions were prepared, providing the corresponding carbonate products in excellent yields. The catalyst system also performed the conversion of an epoxidized fatty acid n-pentyl ester into a cyclic carbonate under relatively mild reaction conditions (80 °C, 20 bar, 24 h). This bis(cyclic carbonate) was obtained in high yields and with different cis/trans ratios depending on the co-catalyst used. An allyl alcohol by-product was only observed as a minor product when bis(triphenylphosphine)iminium chloride was used as co-catalyst. Finally, two cyclic carbonates were used as building blocks for the preparation of non-isocyanate poly(hydroxy)urethanes by reaction with 1,4-diaminobutane.

Lignin-Based Polyurethane: Recent Advances and Future Perspectives.

Polyurethane (PU), as a polymer material with versatile product forms and excellent performance, is used in coatings, elastomers, adhesives, and foams widely. However, the raw materials (polyols and isocyanates) of PU are usually made using petroleum-derived chemicals. With the concern for depletion of petroleum resources and the associated negative impact on the environment, developing technologies that can use renewable raw materials as feedstock has become a research hotspot. Lignin, as an abundant, natural, and renewable organic carbon resource, has been explored as raw material for making polyurethanes because it possesses rich hydroxyl groups on its surface. Meanwhile, compared to vegetable oils, lignin does not compete with food supply and performance of the resulting products is superior. Lignin or modified lignin has been shown to impart the polyurethane material with additional functionalities, such as UV-blocking ability, hydrophobicity, and flame retardancy. However, the utilization of lignin has encountered some challenges, such as product isolation, heterogeneity, aggregation, steric hindrance, and low activity. This paper summarizes recent research progress on utilizing lignin and modified lignin for bio-based polyurethane synthesis with a focus on elastomers and foams. Opportunities and challenges for application of the lignin-based polyurethanes in various fields are also discussed.

One‐Pot Two‐Step Synthesis of Hydroxymethylated Unsaturated VHOSO and Its Application to the Synthesis of Biobased Polyurethanes

AbstractA one‐pot two‐step procedure is developed to catalytically convert very high‐oleic sunflower oil (VHOSO) into hydroxymethylated unsaturated derivatives featuring both primary alcohols and carbon–carbon double bonds. The degree of functionalization in alcohols and C═C double bonds can be accurately controlled affording low and high substituted hydroxymethylated VHOSO. The key point to achieve such control is to partly hydroformylate the C═C bonds at 80 °C and to subsequently reduce the reaction temperature to 20 °C to selectively reduce the aldehydes, while keeping a high CO/H2 pressure. Step‐growth polymerization of highly substituted hydroxymethylated VHOSO with cyclohexyl isocyanate or 4,4ʹ‐methylenebis(cyclohexyl isocyanate) furnishes biobased polyurethanes with improved thermal stability compared to similar polyurethanes synthesized from castor oil.Practical Applications: This study highlights the implementation of triglycerides featuring both C═C double bonds and hydroxymethyl groups. The synthesis proceeds through a one‐pot two‐steps procedure that consists of a hydroformylation reaction at 80 °C followed by a hydrogenation reaction carried out at room temperature. This simple synthetic procedure is of major interest in a context of an industrial–environmental approach. The high reactivity of the obtained primary alcohols allows the synthesis of bio‐PUs, displaying untouched C═C double bonds, which could be further functionalized. This finding is of importance as the obtained bio‐PUs can be used in many industrial areas such as foams, elastomers, thermoplastics, thermosets, adhesives, coatings, sealants and fibers.

Synthesis of bio-based polyurethanes from Kraft lignin and castor oil with simultaneous film formation

Kraft lignin (KL) and castor oil (CO) were used as polyols in the synthesis of bio-based polyurethanes (PUs) in the absence of both solvents and catalysts at room temperature with simultaneous film formation. KL was purified (PKL), and both KL and PKL were fully characterized. CO was mixed with different percentages of PKL (0%, 10%, 30%, and 50%), as well as with polymeric methyl phenyl diisocyanate. After degassing, the reaction mixture was stirred; when the medium viscosity was suitable for spreading, it was poured onto a glass plate, and the thickness was adjusted using an extender. The storage modulus (E′, 25 °C) and tensile strength of the lignopolyurethane films (LignoPUCOPKL) were higher than those of the control film (PUCO). LignoPUCOPKL30 and LignoPUCOPKL50 did not break under the conditions that the other films broke under. It was noted phase segregation (rigid and flexible domains) for LignoPUCOPKL30 and LignoPUCOPKL50, and the glass transition temperature (Tg) of the flexible domains (96.2 °C and 52.3 °C, respectively) was higher than that of PUCO (8.4 °C). The formed films were also characterized by scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, contact angles, and swelling tests. To our knowledge, the approach of this study is unprecedented.

Microbial Conversion of Vegetable Oil to Hydroxy Fatty Acid and Its Application to Bio-Based Polyurethane Synthesis.

New polyurethanes were synthesized based on dihydroxy fatty acid obtained by the microbial conversion of olive oil. Monounsaturated 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) was produced from olive oil by Pseudomonas aeruginosa PR3 and reacted with hexamethylene diisocyanate (HMDI) at different ratios to form polyurethanes. Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry confirmed the synthesis of DOD. The thermal and tensile properties of the polyurethanes were investigated by differential scanning calorimetry, thermogravimetric analysis, and a universal testing machine. At an isocyanate/hydroxyl ratio of 1.4, the polyurethane exhibited an elongation at break of 59.2% and a high tensile strength of 37.9 MPa. DOD was also mixed with polycaprolactone diol or polyethylene glycol at different weight ratios and then reacted with HMDI to produce new polyurethanes of various properties. These polyurethanes displayed higher elongation at break and good thermal stability. This is the first report on the synthesis of polyurethanes based on DOD produced by the microbial conversion of vegetable oil.

Development of High Performance Polyurethane Elastomers Using Vanillin-Based Green Polyol Chain Extender Originating from Lignocellulosic Biomass

Vanillin can be obtained from waste of lignocellulosic bioresources with various methods.1−3 Such vanillin was used as chain extender [divanillin-ethanol amine conjugate (DV-EA)] after its dimerization and further modification with ethanolamine in the synthesis of biobased polyurethane, thereby increasing wt % of biocontents in the final polymer. 1,4-Butanediol often used as a general chain extender in polyurethane synthesis was replaced partially with DV-EA. The generated polyurethane hard segment consists of DV-EA polyol and MDI (methylene diisocyanate) units or 1,4-butanediol and MDI units, respectively. The properties of the DV-EA-based polyurethane were investigated with differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analyzer (DMA), X-ray diffraction spectroscopy (XRD), and universal testing machine (UTM). The results showed that this advanced polyurethane has 128% of Young’s modulus and 147% of increased strain compared to those of control, while its st...

Bio-based polyurethane applied as matrix of fiberglass reinforced composite

Purpose: of this paper was to develop and to characterize the mechanical behaviour of a structural composite obtained from a bio-based polyurethane matrix reinforced with fiberglass. Design/methodology/approach: Castor oil and Kraft lignin-containing polyol was applied for bio-based polyurethane synthesis. Structural composite was obtained by reinforcing this renewable source bio-based polymer with fiberglass mat. Polyester resin composite was also obtained for comparison, following the same process and reinforcement conditions. Mechanical characterization was carried out through uniaxial tensile, flexural strength, Izod impact tests and additionally scanning electron microscopy (MEV). Findings: Bio-based polyurethane composite was obtained and presented higher ultimate tensile strength (UTS) and equivalent impact resistance in comparison to polyester matrix composite. Research limitations/implications: Effects of Kraft lignin and fiberglass contents changing on mechanical properties might be investigated in future researches. Practical implications: Revalorization of Kraft lignin. 50 million tons of lignin are produced worldwide every year as by-product of pulp and paper manufacturing. The most part of this Kraft lignin is currently burned for energy generation. Originality/value: Results indicated the possibility of reusing this industrial wasted by-product at large scale as polymeric matrix for structural composite, in which high UTS and impact resistance are required.

One-Pot Conversion of Epoxidized Soybean Oil (ESO) into Soy-Based Polyurethanes by MoCl₂O₂ Catalysis.

An innovative and eco-friendly one-pot synthesis of bio-based polyurethanes is proposed via the epoxy-ring opening of epoxidized soybean oil (ESO) with methanol, followed by the reaction of methoxy bio-polyols intermediates with 2,6-tolyl-diisocyanate (TDI). Both synthetic steps, methanolysis and polyurethane linkage formation, are promoted by a unique catalyst, molybdenum(VI) dichloride dioxide (MoCl2O2), which makes this procedure an efficient, cost-effective, and environmentally safer method amenable to industrial scale-up.

A novel polyurethanes from epoxidized soybean oil synthesized by ring opening with bifunctional compounds

The present work reports the first synthesis of biobased polyurethanes utilizing soy-based polyols that are synthesized by epoxy ring opening of epoxidized soybean oil with chemicals bearing two different functionalities. Apart from polyols, the syntheses of which are described in our previous report where thioglycolic acid (TGA) and methyl ester of TGA (MTGA) were utilized for ring opening, a new polyol that was prepared by epoxy ring opening with glycolic acid (GA) was used for the synthesis of the polyurethanes. GA, which has both hydroxyl and carboxyl functionality, was used to open epoxy ring for the first time. The soybean oil-based polyurethanes (PUs) were formed by the reaction of 4,4′-methylenebis(phenyl isocyanate) (MDI) with the polyols that were synthesized using TGA (polyol-1), GA (polyol-2) and MTGA (polyol-3) to open epoxy rings, in bulk. The PUs were characterized using DSC, FTIR, XRD, SEM and thermogravimetric analysis. New polyurethanes demonstrated a wide range of tensile properties ranging from very flexible to rigid (from 3.44 to 39.7 MPa) as the molar ratio of OH to NCO was changed from 1.85/1 to 2.12/1. With the same polyol/MDI ratio, the best tensile properties were obtained with polyol 1 which has the highest OH functionality.

Synthesis and Characterization of Polyurethanes with High Renewable Carbon Content and Tailored Properties

Thermoplastic and cross-linked biobased polyurethanes with a renewable carbon content ranging from 78 to 98% were synthesized and characterized. The macrodiol and the diisocyanate used were derived from renewable source, the first from castor oil and the second from fatty acid. Moreover, the chain extenders employed were derived from corn sugar and polysaccharides. The effect of component molar ratios and chain extender and cross-linker structure on the final properties was analyzed. Thermal analysis revealed that polyurethanes are formed by amorphous and crystalline domains. It was also observed that the crystallinity of the material is related to the molar ratio of the components and also their structure. Besides, mechanical properties and morphology were tightly dependent on the overall crystallinity, allowing the synthesis of biobased polyurethanes with tailored properties and high renewable carbon content.

Synthesis of novel high primary hydroxyl functionality polyol from sunflower oil using thiol-yne reaction and their application in polyurethane coating

In this study, novel bio-based polyurethanes that have characteristics of both thermosets and thermoplastics were prepared. The polyol functionalized by a high number of hydroxyl groups was synthesized and its application in polyurethanes, a well-known polymer in coating industry, was investigated. Sunflower oil was decorated for the first time with propargyl groups by ring-opening of epoxied groups using boron trifluoride diethyl etherate as catalyst. The polyol is obtained by photochemical thiol-yne coupling functionalization of propargylated oil in presence of mercaptoethanol in an economical, and environmental friendly procedure. The chemical structure of this sunflower based polyol and its intermediates were determined by 1H NMR and FT-IR analysis. A series of polyurethanes containing various NCO/OH molar ratio were synthesized by a one-step procedure. The properties of the polyurethanes were studied by performing tensile testing, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). A facile and green method for the synthesis of bio-based polyurethanes and their application as a transparent coating made them exponentially advantageous.