Urethane Formation Research Articles

Asynchronous Ring Opening of Cyclic Carbonate and Glycidyl Ether Induced Phase Evolution Towards Heat-Free and Rapid-Bonding Superior Epoxy Adhesive.

Structural adhesives that do not require heating are in high demand in the automotive and electronics industries. However, it remains a challenge to develop robust adhesives that rapidly achieve super adhesion near ambient temperature. Herein, a room-temperature curable, fast-bonding, and super strong epoxy-based structural adhesive was designed from the perspective of cross-scale structure, which lies in threefold pivotal aspects: (i) high branching topology of glycerol carbonate-capped polyurethane (PUGC) increases the kinetics of the ring-opening reaction, contributing to fast crosslinking and the formation of abundant urethane and hydroxyl moieties; (ii) asynchronous crosslinking of epoxy and PUGC synergistically induces phase separation of PUGC within the epoxy resin and the resulting PUGC domains surrounded by interpenetrated shell serves to efficiently toughen the matrix; (iii) abundant dynamic hydrogen bonds including urethane and hydroxyl moieties, along with the elastomeric PUGC domains, dissipate energy of shearing force. As a result, the adhesive strength rapidly grows to 16 MPa within 4 hours, leveling off to 21 MPa after 7 hours, substantially outperforming commercial room-temperature curable epoxy adhesives. The results of this study could advance the field of high-performance adhesives and provide valuable insights into designing materials for efficient curing at room temperature.

Asynchronous Ring Opening of Cyclic Carbonate and Glycidyl Ether Induced Phase Evolution Towards Heat‐Free and Rapid‐Bonding Superior Epoxy Adhesive

AbstractStructural adhesives that do not require heating are in high demand in the automotive and electronics industries. However, it remains a challenge to develop robust adhesives that rapidly achieve super adhesion near ambient temperature. Herein, a room‐temperature curable, fast‐bonding, and super strong epoxy‐based structural adhesive was designed from the perspective of cross‐scale structure, which lies in threefold pivotal aspects: (i) high branching topology of glycerol carbonate‐capped polyurethane (PUGC) increases the kinetics of the ring‐opening reaction, contributing to fast crosslinking and the formation of abundant urethane and hydroxyl moieties; (ii) asynchronous crosslinking of epoxy and PUGC synergistically induces phase separation of PUGC within the epoxy resin and the resulting PUGC domains surrounded by interpenetrated shell serves to efficiently toughen the matrix; (iii) abundant dynamic hydrogen bonds including urethane and hydroxyl moieties, along with the elastomeric PUGC domains, dissipate energy of shearing force. As a result, the adhesive strength rapidly grows to 16 MPa within 4 hours, leveling off to 21 MPa after 7 hours, substantially outperforming commercial room‐temperature curable epoxy adhesives. The results of this study could advance the field of high‐performance adhesives and provide valuable insights into designing materials for efficient curing at room temperature.

Effect of 4-[2-(dimethylamino)ethyl]morpholine, and N,N-dimethylbenzylamine on urethane formation - A theoretical study

The formation of urethane through the reaction between phenyl isocyanate (PhNCO)–butan-1-ol (BuOH) was investigated. The reactions, without and in the presence of 4-[2-(dimethylamino)ethyl]morpholine (DMAEM), and N,N-dimethylbenzylamine (DMBA) catalysts have been examined using the BHandHLYP/6-31G(d) and G3MP2BHandHLYP levels of theory. The SMD implicit solvent model has been applied to simulate the solvent effect. As the reaction mechanism contains protonation steps, therefore the proton affinity for the selected catalysts has also been determined. Furthermore, the two selected catalysts have been compared. DMAEM contains different cyclic and aliphatic nitrogen functional groups, while the DMBA contains only aliphatic catalytic site. All in all, the presence of the catalysts significantly changes the reaction mechanism and the energetics of the reaction compared to the catalyst-free case. It was found that the cyclic amine has a slightly greater effect on the energetics of the catalytic reaction compared to the aliphatic one.

Urethane Synthesis in the Presence of Organic Acid Catalysts-A Computational Study.

A general mechanism for catalytic urethane formation in the presence of acid catalysts, dimethyl hydrogen phosphate (DMHP), methanesulfonic acid (MSA), and trifluoromethanesulfonic acid (TFMSA), has been studied using theoretical methods. The reaction of phenyl isocyanate (PhNCO) and butan-1-ol (BuOH) has been selected to describe the energetic and structural features of the catalyst-free urethane formation. The catalytic activities of DMHP, MSA, and TFMSA have been compared by adding them to the PhNCO-BuOH model system. The thermodynamic properties of the reactions were computed by using the G3MP2BHandHLYP composite method. It was revealed that in the presence of trifluoromethanesulfonic acid, the activation energy was the lowest within the studied set of catalysts. The achieved results indicate that acids can be successfully employed in urethane synthesis and the mechanism was described.

Towards lignin-based polyurethanes: a computational study of the influence of the reactants structure on the formation of urethanes in the presence of tin(II) dicarboxylate as a catalyst

An in-depth computational investigation of the tin-catalysed reaction of an alcohol with an isocyanate forming a urethane has been performed to elucidate the influence of the reactants, most importantly the type of alcohol or phenol, on its kinetics. The model alcohols were chosen based on those alcohol moieties present in lignin and comprised aliphatic, aromatic and benzylic alcohols, and reactions with both aliphatic and aromatic isocyanates were studied by modelling the rate-determining step of the urethane formation based on the mechanism proposed by Devendra et al. The results show that N-coordination is both kinetically and thermodynamically favoured for all reactions under consideration. Aliphatic alcohols react more readily than phenols with an aliphatic isocyanate, while benzylic alcohols react similarly to a bulky aliphatic alcohol. In the case of phenols, the kinetics are not influenced by the presence and/or number of ortho‑methoxy groups, but these will slightly alter the thermodynamics of the reaction. Aliphatic alcohols show slightly improved kinetics when reacting with an aromatic isocyanate, whereas phenols show no such preference. The reactions with the aliphatic isocyanate were also modelled in DMSO, but no significant changes in reaction kinetics were observed.

Low-temperature crosslinking characteristics of interpenetrating polymer networks with dual-curable amine-based blocked isocyanate for automotive 1 K clearcoats

Interpenetrating polymer network (IPN) clearcoat systems were developed using two distinct thermal crosslinking reactions: urethane formation reaction and free radical polymerization. Specifically, an amine-based dual-curable blocked isocyanate crosslinker (BITBEMA) was employed to establish additional independent networks within IPNs by utilizing dissociated blocking groups through free radical polymerization. To validate the formation of the IPN and its suitability for a low-temperature curing process, the thermal deblocking characteristics and crosslinking dynamics of the dual-curable 1 K clearcoat were confirmed via various experimental methods, including rheological tests, thermogravimetric analyses, dynamic mechanical analyses, and nano-indentation tests. The influence of the IPNs on the crosslinking characteristics was examined and compared with clearcoat systems featuring only a urethane formation network. Both semi-IPN and full-IPN configurations demonstrated enhanced thermal and mechanical properties in contrast to the mono-curable 1 K clearcoat system, especially at low curing temperatures.

Mn(III) O^N^O Complexes as Water-tolerant and Environmentally Benign Catalysts for Polyurethane Foam Synthesis.

Polyurethanes are synthesized on industrial scale by the reaction of diisocyanates with diols in the presence of catalysts which are commonly based on tin complexes and amines. However, due to the toxicity and volatility of these tin catalysts and amines, there is the need to develop new catalysts that are more environmentally benign. Herein, we report the synthesis of O^N^O pincer-ligated Mn(III) and Fe(III) complexes that serve as suitable catalysts for urethane formation and are stable to hydrolysis as predicted by computations and observed experimentally. The O^N^O pincer scaffold is vital to the activity of these catalysts, simultaneously ensuring increased solubility in the reaction medium as well as providing a stable framework upon dissociation of co-ligands in the catalytic cycle. In silico mechanistic investigations for urethane formation show that the stabilization of active species in square-planar geometries enabled by these O^N^O ligands permit the simultaneous coordination of alcohol and isocyanate in suitable configuration at the metal center.

Stoichiometric reaction and catalytic effect of 2-dimethylaminoethanol in urethane formation.

A computational study of the stoichiometric reaction and catalytic effect of 2-dimethylaminoethanol (DMEA) in urethane formation was performed. DMEA, besides its catalytic tertiary amine site, contains a hydroxyl group that can react with isocyanates and thus, it can affect the synthesis of polyurethane. In the catalytic system, the reaction between phenyl isocyanate and butan-1-ol, involving DMEA as a catalyst, was investigated. Meanwhile, for the competitive stoichiometric process, the reaction between phenyl isocyanate and DMEA was also considered. Both reactions were investigated by using the G3MP2BHandHLYP composite method and acetonitrile was chosen as the solvent. It was revealed that both pathways (catalytic and stoichiometric processes) are similar thermodynamically, but the catalytic reaction is preferred kinetically, which indicates the applicability of DMEA in urethane synthesis.

Thermally reprocessable bio-based polyhydroxyurethane vitrimers

Vitrimers present one way to address growing demand for sustainably sourced, recyclable thermoset polyhydroxyurethanes (PHUs). We employ vinylogous urethane formation for dynamic bonding, using amine-terminated bio-sourced PHUs (prepared via terpolymerization of diglycerol dicarbonate (DGC) with Priamine 1074 and 1,10-diaminodecane (DAD)) as crosslinkers with ketone-functional copolymers. The latter are synthesized via atom transfer radical copolymerization (ATRP) of an alkyl methacrylate (C13MA, with average side-chain length of 13 carbons) with (2-acetoacetoxy) ethyl methacrylate (AAEMA) (initial AAEMA mole fraction = 0.1–0.4). By manipulating copolymer functionality, thermoset PHUs (Young's moduli spanning from 31 ± 1.5 kPa to 133 ± 5.7 kPa) are obtained. Furthermore, as ketone group concentration increases, networks became tighter, with slower relaxation rates and increased apparent activation energy of stress relaxation, in agreement with calculated molecular weight between crosslinks obtained rheologically. Finally, thermoset PHUs can be effectively recycled three times through remolding at 100 °C without compromising their mechanical properties.

Synthesis and characterization of waterborne bio-based hybrid isocyanate-free poly (hydroxy urethane)-poly(methacrylate) latexes with vitrimeric properties

Non-isocyanate poly(urethane)s (NIPU)s have emerged as an environmentally friendly alternative for conventional polyurethanes, but several challenges remain towards their wide-scale adoption (e.g., attainment of high molecular weights for sufficiently effective mechanical properties and ease of application). Adopting NIPUs as hybrid polymer-polymer particles with methacrylic monomers is one route towards obtaining higher overall molecular weight, improving properties, and introducing advantages of methacrylate functionality. First, NIPU latex was synthesized using dicarbonate terminated poly (propylene glycol) and the commercial vegetable oil-based diamine Priamine 1075 via step miniemulsion polymerization yielding stable particles with sizes <220 nm. Then, the NIPU latex was used as the seed for the synthesis of hybrid NIPU-poly(methacrylate) particles via conventional radical emulsion statistical copolymerization of a long side chain (13 alkyl groups) alkyl methacrylate (C13MA) and isobornyl methacrylate (IBOMA). Two polymeric phases were observed in cryo-microtomed TEM of the dried latexes at ambient temperature, indicating core-shell phase-separated morphologies. Moreover, 2-acetoacetoxyethyl methacrylate (AAEMA) was introduced in the formulation containing the methacrylate phase to impart dynamic covalent crosslinking into the hybrid via ketone-amine vinylogous urethane formation, resulting in materials with stress relaxation up to 90% at 130 °C and one-time recycled films with similar stress-strain profiles as the original films.

Effect of morpholine, and 4-methylmorpholine on urethane formation: a computational study

A theoretical study of urethane formation through the reaction of phenyl isocyanate and butan-1-ol was carried out, without and in the presence of morpholine, and 4-methylmorpholine catalysts. The reaction with and without catalysts was studied at BHandHLYP/6-31G(d) and G3MP2BHandHLYP levels of theories. The reaction mechanism in the presence of catalysts differs significantly from the catalyst-free case and includes seven steps. The catalyst-free system was investigated along with the catalytic process, the geometries were optimized, and the corresponding thermodynamic properties were calculated. Calculated reactant complexes were compared with crystal structures of morpholine, and 4-methylmorpholine complexed with diols found in the literature. The structures were strikingly similar and thus, the validity of the proposed and studied general organocatalytic reaction mechanism was partially verified. Meanwhile, an irregularity in the energy profile occurred due to the zwitterionic nature of an intermediate. To handle the irregularity, a correction was implemented which handles the appearance of a zwitterionic structure and the corresponding energetic properties. The results showed that morpholine is less effective catalyst compared to 4-methylmorpholine, which can be associated with the difference in their PA (1523.95 and 963.07 kJ/mol, respectively). The current results prove the important role of amine catalysts in urethane synthesis which can be applied in polyurethane catalyst design and development.

Controlling the reactivity of hydrophilic bark extractives as biopolyols in urethane-formation reactions using various catalysts

The composition, functionality, and reactivity of black alder (Alnus glutinosa) bark extractives as a biopolyol with polymeric diphenyl methane diisocyanate (PMDI) have been studied using a variety of methods, including HPLC, GPC, GC, wet chemistry, and isothermal calorimetry. The Black alder (BA) bark extractives were identified as a prospective polyol consisting mainly of the oregonin-xyloside form of diarylheptanoid, which contains OH groups that are almost equally represented by phenolic and aliphatic origins. To identify catalysts that effectively increase the reactivity of low-active phenolic OH groups in urethane formation reactions, the kinetics of extractives and model compounds' interaction with PMDI catalyzed with tin organic, dibutyl tin dilaurate (DBTDL) and tertiary amine, 1,4-diazabicyclo[2.2.2]octane (DABCO) catalyst in dimethylsulfoxide (DMSO) solution were studied. The results showed that DABCO resulted in a fourfold higher reactivity of phenolic groups with PMDI compared to DBTDL catalyzed reactions. Furthermore, the reactivity of phenolic groups with PMDI catalyzed by DABCO was almost twofold greater than that of aliphatic OH catalyzed by DBTDL. The second-order constants of 31.9 × 10−4 mol·L−1·s−1 and 53.7 × 10−4 mol·L−1·s−1 were determined for the interaction of extractives with PMDI in the presence of DBTDL and DABCO, respectively. The disappearance of the radical scavenging effect of phenolic compounds in extractives derived PU elastomers obtained with DABCO catalyst indicates complete reactions of phenolic groups with isocyanate, while these groups remain partly free in the case of DBTDL catalysis. It is assumed that a combination of DBTDL and DABCO catalysts will be necessary to achieve high crosslinking while leaving a small portion of free phenolic groups in the bio-based PU network, thus obtaining material with high mechanical properties and thermal oxidative stability.

Impact of Bark-Sourced Building Blocks as Substitutes for Fossil-Derived Polyols on the Structural, Thermal, and Mechanical Properties of Polyurethane Networks.

The hydrophilic extractives isolated from black alder (Alnus glutinosa) bark through hot water extraction were characterized as novel renewable macromonomers capable of forming polyurethane (PU) networks based on a commercial polyisocyanate, with partial or complete replacement of petroleum-derived polyol polyether. The bark-sourced bio-polyol mainly consists of the xyloside form of the diarylheptanoid oregonin, along with oligomeric flavonoids and carbohydrates, resulting in a total OH group content of 15.1 mmol·g-1 and a molecular weight (Mn) of approximately 750 g∙mol-1. The 31P NMR data confirmed a similar proportion of aliphatic OH and phenolic groups. Three-component PU compositions were prepared using polyethylene glycol (Mn = 400 g∙mol-1), bio-polyol (up to 50%), and polymeric diphenylmethane diisocyanate, which were pre-polymerized in tetrahydrofuran (THF) solution with tin organic and tertiary amine catalysts. The resulting mixture was cast and subjected to thermal post-curing. Calculation and experimental data confirmed the crosslinking activity of the bark-sourced bio-polyol in PU, leading to an increase in glass transition temperature (Tg), a decrease in sol fraction yield upon leaching of cured PU networks in THF, a significant increase in Young's modulus and tensile strength. The macromonomers derived from bark promoted char formation under high temperature and oxidative stress conditions, limiting heat release during macromolecular network degradation compared to bio-polyol-free PU. It was observed that amine catalysts, which are active in urethane formation with phenolic groups, promoted the formation of PU with higher Tg and modulus at tensile but with less limitation of heat liberation during PU macromolecular structure degradation. The high functionality of the bark-derived bio-polyol, along with the equal proportion of phenolic and aliphatic OH groups, allows for further optimization of PU characteristics using three variables: increasing the substitution extent of commercial polyethers, decreasing the NCO/OH ratio, and selecting the type of catalyst used.

Reactivity of New Monomers of the Polyurethanes Green Chemistry, the Reaction Mechanism, and the Medium Effect

The influence of the substituents inductive effect and the proton-donor OH group in the substituted cyclocarbonates differing in the alkyl chain length on the activation barrier of their aminolysis reaction, which underlies the process of urethane formation without the participation of isocyanates, has been studied. Account for the solvent molecules has allowed quantitative interpretation of the process regularities. Kinetics of the model aminolysis reaction of a series of monomers in DMSO has been investigated.

Dependence of Photothermal Rate Enhancements of Urethane Formation upon the Nature of Light Exposure and Solution Viscosity

The photothermal effect of nanoparticles naturally results in nanometer scale heat sources. Despite their highly localized nature, these heat sources can be used to drive bulk scale chemical transformations. However, due to the localization in both time and space, it is reasonable to expect that the time scale of heating, as well as transport of reactive species into and out of the heated volumes during this time, might play a role in determining the efficacy of photothermal heating for driving chemical reactions. Herein, we report an investigation into these effects for the reaction between hexamethylene diisocyanate and a series of alcohols to form urethane bonds. The length of photothermal heating is controlled via the duration of light exposure, using either a modulated continuous wave (2 min duty cycle) or a nanosecond pulse (8 ns pulses) laser that deliver nearly the same total energy to the system. Mass transport is controlled by changing the alcohol from butanol to butanediol to a polyester diol, resulting in reaction mixtures that change their viscosity from 1.66 to 206 cSt. We use infrared spectroscopy to follow the urethane production and associated isocyanate consumption. We then fit the course of the reaction to a kinetic model from which we extract rate constants used to quantify the degree of photothermal rate enhancement. For the chemical systems used, we find no significant dependence on viscosity. We also find that, for the light sources used, the average rate enhancement is not significantly affected by the length of light exposure, but the rate of the reaction during the time of exposure increases with larger instantaneous power.

Effects of NCO/OH Ratios on Bio-Based Polyurethane Film Properties Made from Acacia mangium Liquefied Wood.

The compatibility between isocyanate and polyol plays an important role in determining a polyurethane product's performance. This study aims to evaluate the effect of varying the ratios between polymeric methylene diphenyl diisocyanate (pMDI) and Acacia mangium liquefied wood polyol on the polyurethane film properties. A. mangium wood sawdust was liquefied in polyethylene glycol/glycerol co-solvent with H2SO4 as a catalyst at 150 °C for 150 min. The A. mangium liquefied wood was mixed with pMDI with difference NCO/OH ratios to produce film through the casting method. The effects of the NCO/OH ratios on the molecular structure of the PU film were examined. The formation of urethane, which was located at 1730 cm-1, was confirmed via FTIR spectroscopy. The TGA and DMA results indicated that high NCO/OH ratios increased the degradation temperature and glass transition from 275 °C to 286 °C and 50 °C to 84 °C, respectively. The prolonged heat appeared to boost the crosslinking density of the A. mangium polyurethane films, which finally resulted in a low sol fraction. From the 2D-COS analysis, the hydrogen-bonded carbonyl (1710 cm-1) had the most significant intensity changes with the increasing NCO/OH ratios. The occurrence of the peak after 1730 cm-1 revealed that there was substantial formation of urethane hydrogen bonding between the hard (PMDI) and soft (polyol) segments as the NCO/OH ratios increased, which gave higher rigidity to the film.

Urethane formation in the presence of 2,2-dimorpholinodiethylether (DMDEE) and 1,4-dimethylpiperazine (DMP) – A combined experimental and theoretical study

The reaction of phenyl isocyanate (PhNCO) and butan-1-ol (BuOH) in acetonitrile without and in the presence of two amine catalysts, 2,2-dimorpholinodiethylether (DMDEE) and 1,4-dimethylpiperazine (DMP), has been studied, using computational and experimental tools. Kinetic investigation of the alcoholysis of phenyl isocyanate (PhNCO) using stoichiometric butan-1-ol (BuOH) in acetonitrile was examined as well. The same reaction was investigated by using density functional theory and composite methods (BHandHLYP/6-31G(d) and G3MP2BHandHLYP) in combination with the SMD implicit solvent model. The results showed that the barrier height of the reaction significantly decreased (>120 kJ/mol) in the presence of catalysts. The computed and measured thermodynamic properties were in good agreement with each other. This proves the important role of amine catalysts in urethane synthesis.

THE STUDY OF INTERMOLECULAR INTERACTIONS IN THE POSS-CONTAINING NANOCOMPOSITES BASED ON POLYURETHANE AND POLYURETHANE/POLY(HYDROXYPROPYL METHACRYLATE) MATRICES

The nanocomposites based on polyurethane matrix and multicomponent polymer matrices consisting of polyurethane and poly(hydroxypropyl methacrylate) with different contents of the last, and 1,2-propanediolisobutyl polyhedral oligomeric silsesquioxane (1,2-propanediolisobutyl-POSS), which was used as a functionalized nanofiller, were synthesized. The influence of the content of 1,2-propanediolisobutyl-POSS on intermolecular interactions and structural features of the nanocomposites was investigated by the method of IR-spectroscopy with Fourier transformation and attenuated total reflection (FTIR-ATR). The study of thermal curing of the model system, which consists of the adduct of trimethylolpropane with toluene diisocyanate and 1,2-propanediolisobutyl-POSS, made it possible to conclude that 1,2-propanediolisobutyl-POSS participates in the reaction of urethane formation using of one of the terminal hydroxyl groups, and it is incorporated into the polymer chain between cross-linking of polyurethane networks. The investigation of multicomponent polymer matrices by FTIR-ATR spectroscopy was done and was shown that photopolymerization of second polymer poly(hydroxypropyl methacrylate) in the matrix of polyurethane was completed by the opening of a double bond and the formation of a linear polymer in the composition of semi-IPN. Studies of nanocomposites based on multicomponent polymer matrices consisting of polyurethane and poly(hydroxypropyl methacrylate) with 15 and 30 % of the last by FTIR-ATR spectroscopy demonstrated the presence of POSS in the nanocomposites and the influence of POSS content on the structure of the studied systems and on the degree of phase separation. The POSS is "embedded" into the polymer chain between cross-linking of the polyurethane networks, with the additional formation of a complex system of intermolecular hydrogen bonds between the carboxyl and amine components of urethane groups in the nanocomposites.

One-Pot Synthesis of Hyperbranched Polyurethane-Triazoles with Controlled Structural, Molecular Weight and Hydrodynamic Characteristics.

We report a simple and convenient approach to the one-pot synthesis of hyperbranched polyurethane-triazoles with desirable properties. This method is based on in situ generation of an AB2 + A2 + B4 azide-acetylene monomer mixture of known composition, due to quantitative reactions of urethane formation between isophorone diisocyanate (IPDI), 1,3-diazidopropanol-2 (DAPOL) (in the first stage) and propargyl alcohol (in the second stage). The obtained monomer mixture can be involved in step-growth polymerization by azide-alkyne cycloaddition without additional purification (in the third stage). The properties of the resulting polymers should depend on the composition of the monomer mixture. Therefore, first the model revealing the correlation between the monomer composition and the ratio and reactivity of the IPDI and DAPOL active groups is developed and proven. In addition, the newly developed structural kinetic model considering the substitution effect at polyaddition of the complex mixture of monomers allows the prediction of the degree of branching of the target polymer. Based on our calculations, the hyperbranched polyurethane-triazoles were synthesized under found conditions. All products were characterized by 1H NMR, FTIR, SEC, DLS, DSC, TGA and viscometry methods. It was shown that the degree of branching, molecular weight, intrinsic viscosity, and hydrodynamic radius of the final hyperbranched polymers can be specified at the first stage of one-pot synthesis. The obtained hyperbranched polyurethane-triazoles showed a degree of branching from 0.21 to 0.44 (calculated DB-0.25 and 0.45, respectively).

Experimental and Theoretical Study of Cyclic Amine Catalysed Urethane Formation

The alcoholysis of phenyl isocyanate (PhNCO) using stoichiometric butan-1-ol (BuOH) in acetonitrile in the presence of different cyclic amine catalysts was examined using a combined kinetic and mechanistic approach. The molecular mechanism of urethane formation without and in the presence of cyclic amine catalysts was studied using the G3MP2BHandHLYP composite method in combination with the SMD implicit solvent model. It was found that the energetics of the model reaction significantly decreased in the presence of catalysts. The computed and measured thermodynamic properties were in good agreement with each other. The results prove that amine catalysts are important in urethane synthesis. Based on the previous and current results, the design of new catalysts will be possible in the near future.