Melt Stability Research Articles

Unveiling the glass‐forming ability of MOF: A high‐throughout simulation and data mining

AbstractThe correlation between the glass‐forming ability (GFA) of Metal–Organic Frameworks (MOFs) and their structural characteristics remains poorly understood. To address this gap, we analyze over 20,000 MOFs from the MOF database, comparing geometric and electronic order parameters between zeolitic imidazolate frameworks (ZIFs) and other MOFs. Our findings reveal a set of order parameters that effectively capture the thermal stability, and GFA of MOFs, acting as structural genes to predict glass formation. Through molecular dynamics simulations on representative ZIFs structures, we validate the reliability of these order parameters, particularly the total bond‐order density (TBOD) and the largest cavity diameter (LCD), for screening potential melt‐quenched MOFs. Furthermore, we predict that external pressure and electric fields can control the TBOD of MOFs, expanding our understanding of their thermal stability. This work identifies structural genes associated with the melt stability of MOFs, and contributes valuable insights into the prediction and understanding of MOFs glass‐forming ability.

Improvement of Sodium-Ion Conductivity in Sulfide Electrolytes for All-Solid-State Batteries

An important material for realizing all-solid-state batteries is a solid electrolyte with high ionic conductivity and excellent compatibility with positive and negative electrodes. Compared to lithium-ion conductors, sodium-ion conducting sulfides are expected to have the advantages of high conductivity and favorable ductility due to the weaker Lewis acidity of sodium ions [1].Sulfide electrolytes with sodium-ion conductivity have been developed during the last decade. To achieve high ionic conductivity, it is effective to prepare glass electrolytes with high sodium content by the rapid-quenching or mechanochemical methods. Crystallization of glass electrolytes can enhance their conductivity by stabilizing a metastable crystalline phase in glass matrix. The conductivity of the Na3PS4 glass increased to 10−4 S cm−1 by crystallization [2]. We reported that the doping of sodium-ion vacancies in Na3SbS4 by partial substitution of W for Sb is effective in enhancing conductivity to the level of 10−1 S cm−1 [3,4]. Based on the high-temperature stability of sodium polysulfide melt, Na2.88Sb0.88W0.12S4 was synthesized directly from a stoichiometric mixture of Na2S, S, Sb and W by heating at ambient pressure followed by cooling [4].Glassy Na3BS3 was also prepared by the same synthetic procedure under ambient pressure without the use of a vacuum-tight container [4]. The Na3BS3 glass showed better Na plating/stripping performance than Na3PS4 and is suitable for contact with negative electrodes [5]. Therefore, an all-solid-state cell was fabricated by using two types of solid electrolytes, Na3BS3 on the Na15Sn4 negative electrode and Na2.88Sb0.88W0.12S4 on the TiS2 positive electrode. The cell operated as a rechargeable battery at room temperature and maintained the coulombic efficiency of almost 100% from the 2nd to 300th cycles [4].

Stability of hydrous basaltic melts at low water fugacity: evidence for widespread melting at the lithosphere-asthenosphere boundary

The upper mantle low velocity zone is often attributed to partial melting at the lithosphere-asthenosphere boundary. This implies that basaltic melts may be stable along plausible geotherms due to the freezing point depression in the presence of water and other incompatible impurities. However, the freezing point depression (ΔT) as a function of water content in the near-solidus basaltic melt (cH2O) cannot be precisely determined from peridotite melting experiments because of difficulties in recovering homogeneous basaltic glasses at high pressures. We therefore used an alternative approach to reinvestigate and accurately constrain the ΔT–cH2O relationship for basaltic melts at the low water fugacities that are expected in the upper mantle. Internally heated pressure vessel (IHPV) experiments were performed at water-saturated conditions in the anorthite-diopside-H2O system at confining pressures of 0.02 to 0.2 GPa and temperatures between 940 and 1450 ℃. We determined the water-saturated solidus, and obtained ΔT by combining our data with reports of dry melting temperatures in the anorthite-diopside system. In another series of experiments, we measured water solubility in haplobasaltic melts and extrapolated cH2O to pressures and temperatures of the water-saturated solidus. By combining the results from these two series of experiments, we showed that the effect of water on ΔT was previously underestimated by at least 50 ℃. The new ΔT–cH2O relationship was then used to revise predictions of melt distribution in the upper mantle. Hydrous melt is almost certainly stable beneath extensive regions of the oceanic lithosphere, and may be present in younger and water-enriched zones of the subcontinental mantle.

The Effect of Energy Parameters of Power Sources on the Structure and Properties of Permanent Joints at Manual Arc Welding

The study presents the results of the research into the effect of the dynamic properties of inverter and diode power sources of welding arc power supply on the stability of melting and transfer of electrode metal into the weld pool. The principal energy parameters of the power source include the rates of rise and fall of short-circuit current, the ratio of arc burning current to short-circuit current, and other related factors. It has been demonstrated that an increase in the rate of change of these parameters within one welding mode microcycle alters the properties of heat and mass transfer, increases the frequency of electrode metal droplet transfer, reduces the size of transferred droplets in the weld pool and the duration of their stay on the electrode end under the influence of the high temperature of the welding arc, and the duration of short circuits. The increase in the mass fraction of alloying elements at their transition from the coated electrode to the weld metal is demonstrated to depend on the rate of change of the main energy parameters of one welding mode microcycle of the inverter power source in comparison with the diode rectifier. An enhancement in the structural integrity and properties of permanent joints during welding has been observed when using an inverter power source for the welding arc with high dynamic properties.

Developing flame retardant solutions for partially aromatic polyamide with phosphine oxides

Partially aromatic polyamides owing to their excellent thermal stability are widely used in high temperature applications, however, like their aliphatic counterparts, they are readily flammable and more challenging to process. In this work, several organophosphorus flame retardants were synthesized and compounded with partially aromatic polyamide and evaluated for their processability, thermal, and fire behaviour. The compounds containing a commercial flame retardant, Exolit® OP 1230 (EX), and two new flame retardants, namely 1,4-phenylenebis(diphenylphosphine oxide) (MP) and (1,1′-biphenyl]-4,4′-diylbis(diphenylphosphine oxide) (BP), showed self-extinguishing capability (i.e., UL94 V0 class) with 4 wt% phosphorus (P) loading, together with a substantial reduction in the pHRR (up to 47 %), with respect to the pristine PAP. Rheological measurements on extended timescales were used to assess the melt stability of partially aromatic polyamide compounds. The presence of MP and BP in the polymer matrix did not trigger any excessive degradation phenomena such as chain scission, branching, or crosslinking reactions, thus, allowing a stable processability similar to a pristine partially aromatic polyamide sample. Finally, analysis of evolved gases during thermal decomposition revealed that MP and BP mainly exert a flame inhibition effect quite early in the decomposition process.

Preparation and characterization of thermo-processable poly(benzimidazole imide)s with soluble and high heat-resistance containing N-phenyl-benzimidazole

In this paper, we present a synthetic strategy for N-phenyl substituted benzimidazole-derived diamines, including 2-(4-(4-aminophenoxy) phenyl)-1-phenyl-1H-benzo[d]imidazole-5-amine (para-diamine) and 2-(3-(4-aminophenoxy) phenyl)-1-phenyl-1H-benzo[d]imidazole-5-amine (meta-diamine). Two distinct series of N-phenyl substituted poly (benzimidazole imide)s (PBIPIs) were synthesized via reaction with different aromatic dianhydrides. The simulation reveals distinct amine reaction activities of two diamine monomers. The obtained PBIPIs exhibit exceptional heat resistance attributed to N-phenyl substituted benzimidazole (BI). The temperature at which weight loss of 5 % (T5%) is in the range of 491–595 °C under N2 environment, while the glass transition temperature is 237–329 °C. The PBIPIs exhibit specific solubility characteristics due to the flexible ether linkage groups' non-coplanarity and bulky pendant benzene groups. The PBIPIs possess tensile strength between 108 and 142 MPa, a tensile modulus of 4.0–5.9 GPa, and an elongation at a break of 4.2–26.4 %, indicating excellent mechanical properties. Additionally, the PBIPI with controlled molecular weight generated from BPADA incorporating 2-(3-(4-aminophenoxy) phenyl)-1-phenyl-1H-benzo[d]imidazole-5-amine (B-BPADA-PA) demonstrates exceptional melt processability. B-BPADA-PA possesses remarkable melt stability since its minimum complex viscosity is only 2100 Pa⋅s at 400 °C, and its melt viscosity ratio is 1.34 at 380 °C.

Mechanical recycling of PET containing mixtures of phosphorus flame retardants

Flame-retarded polymers, such as polyester textiles and sheets, are attracting attention with regard to their sustainability. Mechanical recycling is currently the most frequently used technique for improving the circularity of plastics. However, one complication of mechanical recycling is associated with the (still) inevitable mixtures of polymers and additives, which can influence material stability and significantly deteriorate the mechanical properties of recycled products. In this study, we aim to specifically investigate the interactions between mixtures of phosphorus flame retardants (FRs) in polyethylene terephthalate (PET) and evaluate their potential role in the mechanical recycling of melt-spun fibers. Two highly relevant commercial FRs, namely a DOPO-derivative (DOPO-PEPA or DP) and Aflammit PCO 900 (AF), are added to PET compounds as additives using a melt compounder. The melt stability of PET/FR compounds over extended processing time is assessed by chemical, thermal, and rheological measurements. DP shows a molecular lubrication effect, lowering the melt viscosity of PET, while AF promotes chemical changes (i.e., chain branching/crosslinking). Interestingly, a PET compound containing hybrid mixtures of DP/AF 20/80 (wt.%/wt.%) shows the most stable behavior at high temperatures under both nitrogen and air atmospheres, thus showing a synergistic effect. Most importantly, in a recycling scenario, the stabilization effect persists at diluted concentrations below the typical FR contents in PET. Multiple extrusion cycles are used to assess the repeated processing behavior of the compounds, and the mechanical properties and fire behavior of melt-spun fibers are compared before and after recycling. The results reveal that DP can maintain the mechanical performance of recycled PET/FR fibers, even if it is mixed (contaminated) with AF.

Application of CALPHAD Method for Predicting of Concentration Range of Amorphization of Transition Metals Melts

Early, the efficiency of the CALPHAD (Calculation of Phase Diagrams) method to a targeted search for compositions of amorphous alloys has been shown. The method for predicting the ranges of amorphization is based on the calculation of diagrams of metastable phase transformations between supercooled melts and boundary solid solutions on the base of pure elements. In this work, the model parameters for thermodynamic properties of liquid alloys and boundary solid solutions were summarized in a self-consistent database for the multicomponent Cu–Fe–Ni–Ti–Zr–Hf system. Such database for the multicomponent system is based on a common set of model parameters for boundary binary and ternary systems. This database was used to predict the concentration ranges of amorphization for the quinary Cu–Fe–Ni–Ti–Zr, Cu–Fe–Ni–Ti–Hf and boundary ternary and quaternary systems. The results of calculations are presented along sections in quaternary and quinary systems. The ternary and quaternary equiatomic alloys along with high entropy CuFeNiTiZr and CuFeNiTiHf alloys are trapped into prognosed composition ranges of amorphization. Predicted composition space of amorphization for melts of the Fe–Ni–Ti–Zr system is shown on the concentration tetrahedron. Based on the obtained results, a new criterion for predicting the concentration regions of amorphization of multicomponent melts is proposed, according to which the presence of a sufficient content of metals that are electron acceptors and donors is a chemical factor that affects the thermodynamic stability of melts and determines their glass-forming ability. For multicomponent melts of the Cu–Fe–Ni–Ti–Zr–Hf system the concentration ranges of amorphization correspond to the simultaneous fulfillment of the conditions xFe + xNi + xCu > 0.25 and xTi + xZr + xHf > 0.15, where Fe, Ni, and Cu are electron acceptors and Ti, Zr, and Hf are electron donors.

Force-induced unzipping of DNA in the presence of solvent molecules

The melting of double-stranded DNA (dsDNA) in the presence of solvent molecules is a fundamental process with significant implications for understanding the thermal and mechanical behavior of DNA and its interactions with the surrounding environment. The solvents play an essential role in the structural transformation of DNA subjected to a pulling force. In this study, we simulate the thermal and force induced denaturation of dsDNA and elucidate the solvent dependent melting behavior, identifying key factors that influence the stability of DNA melting in presence of solvent molecules. Using a statistical model, we first find the melting profile of short heterogeneous DNA molecules in the presence of solvent molecules in Force ensemble. We also investigate the effect of solvent's strengths on the melting profile of DNA. In the force ensemble, we consider two homogeneous DNA chains and apply the force on different locations along the chain in the presence of solvent molecules. Different pathways manifest the melting of the molecule in both ensembles, and we found several interesting features of melting DNA in a constant force ensemble, such as lower critical force when the chain is pulled from the base pair close to a solvent molecule. The results provide new insights into the force-induced unzipping of DNA and could be used to develop new methods for controlling the unzipping process. By providing a better understanding of melting and unzipping of dsDNA in the presence of solvent molecules, this study provides valuable guidelines for predicting DNA thermodynamic quantities and for designing DNA nanostructures.

Nucleation, crystal growth, nuclei stability, and polymorph selection in supercooled tolbutamide melt.

Nucleation is an essential step of overall crystallization, yet crystal nuclei are elusive to direct observation due to their small size and transient nature. A method for assessing the nuclei size distribution and growth rate based on selective melting/dissolving was developed recently, making use of the rapid heating/cooling rate available in fast scanning calorimetry. The method was first employed to study the nuclei in the polymer poly-L-lactic acid. Here we investigate the crystal nuclei of tolbutamide, a molecular compound. We show that while the general behavior of tolbutamide is compatible with the classic nucleation theory (CNT) and is in agreement with previous results for poly-L-lactic acid, there are some peculiarities. First, tolbutamide nuclei display extreme thermal stability, surviving heating above the melting onset of the polymorph forming at the same conditions. Second, the nuclei size distribution shows a sharp cut-off at the high end of the distribution. Finally, the difference in the growth rate of nuclei and crystals of tolbutamide is even higher (about 5 orders of magnitude) than what was determined for poly-L-lactic acid previously.

Melt stability of carbonic anhydrase in polyethylene oxide for extrusion of protein–polymer composite materials

Enzymatic membranes manufactured via hot melt extrusion present an exciting, scalable route towards energy efficient separations.

Effect of annealing at Tg on the crystallization behaviors of Au49Ag5.5Pd2.3Cu26.9Si16.3 metallic glass revealed by nanocalorimetry

Crystallization of metallic glass is not only affected by undercooling but also influenced by microstructure. However, the role of structure in the crystallization is still ambiguous. In this study, nanocalorimetry with a rapid quenching rate was used to obtain the critical cooling rates suppressing nucleation and crystal growth, realizing the in-situ preparation of the amorphous phase. Based on the nuclei-free metallic glass, annealing at Tg was performed to tune the microstructure. With a reheating analysis, the consecutive occurrence of relaxation, nucleation, and crystal growth during annealing was distinguished based on the evolution of crystallization heat. Moreover, the effect of annealing and the resulting microstructure evolution on the reheating crystallization was demonstrated. With the formation of nuclei, the stability of the undercooled melt deteriorated, causing the reduction of activation energy (Ea). When crystals formed during annealing, the confined residual amorphous phase was dominant for crystallization, and a higher Ea was observed.

Influence of CeO2 on glass formation, structural and thermal properties of sodium niobium phosphate glass

Cerium is a well-known surrogate to trivalent and tetravalent actinides and has been investigated to explore the structural and thermal characteristics of simulated radwaste-loaded material systems. The solubility and distribution of CeO2 into a sodium niobium phosphate glass have been explored with the objective of developing a host matrix for radioactive waste immobilization. Niobium phosphate glasses of (100-x) (40Na2O–20Nb2O5–40P2O5)-xCeO2 (x = 0, 1, 3, 5, 8, and 10 mol%) compositions are prepared by melt-quenching method and are characterized by X-ray diffractometry (XRD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and scanning electron microscopy (SEM). This study summarises the influence of cerium ion incorporation on the structure, thermal stability, and formation of crystalline phases of the niobium phosphate glass. The various glass stability parameters, such as Hruby (KH), Weinberg (KW), and Lu–Liu (KLL) parameters are estimated to assess the stability of the glass melt against devitrification in the supercooled region. The spectroscopic analysis ascertains the presence of metaphosphate and pyrophosphate networks as primary structural building units in the glass. However, the Raman analysis demonstrates the influence of CeO2 on the network linkages arising from the corner-sharing of NbO6 octahedrons and Nb–O–P bonding in the glass. The CeO2 loading is optimized up to 8 mol% into the base 40Na2O–20Nb2O5–40P2O5 glass matrix without precipitation of any crystalline phase. The glasses are heat treated to obtain glass-ceramics embedded with the crystalline phases, namely, monazite CePO4, NbOPO4, NaNbO3, and niobium phosphate bronze Na6Nb8(PO4)5O15. The microanalysis of these glass ceramics shows that the CeO2 is more aggregated inside the niobium phosphate bronze framework than in the bulk at a higher temperature. It is also observed that the surface crystallization process is a prevalent mechanism for the crystallization of glasses on heating at crystallization onset temperature.

Development of Stereocomplex Polylactide Nanocomposites as an Advanced Class of Biomaterials-A Review.

This review paper analyzes the development of advanced class polylactide (PLA) materials through a combination of stereocomplexation and nanocomposites approaches. The similarities in these approaches provide the opportunity to generate an advanced stereocomplex PLA nanocomposite (stereo-nano PLA) material with various beneficial properties. As a potential "green" polymer with tunable characteristics (e.g., modifiable molecular structure and organic-inorganic miscibility), stereo-nano PLA could be used for various advanced applications. The molecular structure modification of PLA homopolymers and nanoparticles in stereo-nano PLA materials enables us to encounter stereocomplexation and nanocomposites constraints. The hydrogen bonding of D- and L-lactide fragments aids in the formation of stereococomplex crystallites, while the hetero-nucleation capabilities of nanofillers result in a synergism that improves the physical, thermal, and mechanical properties of materials, including stereocomplex memory (melt stability) and nanoparticle dispersion. The special properties of selected nanoparticles also allow the production of stereo-nano PLA materials with distinctive characteristics, such as electrical conductivity, anti-inflammatory, and anti-bacterial properties. The D- and L-lactide chains in PLA copolymers provide self-assembly capabilities to form stable nanocarrier micelles for encapsulating nanoparticles. This development of advanced stereo-nano PLA with biodegradability, biocompatibility, and tunability properties shows potential for use in wider and advanced applications as a high-performance material, in engineering field, electronic, medical device, biomedical, diagnosis, and therapeutic applications.

Review on the Degradation of Poly(lactic acid) during Melt Processing.

This review paper presents an overview of the state of the art on process-induced degradation of poly(lactic acid) (PLA) and the relative importance of different processing variables. The sensitivity of PLA to degradation, especially during melt processing, is considered a significant challenge as it may result in deterioration of its properties. The focus of this review is on degradation during melt processing techniques such as injection molding and extrusion, and therefore it does not deal with biodegradation. Firstly, the general processing and fundamental variables that determine the degradation are discussed. Secondly, the material properties (for example rheological, thermal, and mechanical) are presented that can be used to monitor and quantify the degradation. Thirdly, the effects of different processing variables on the extent of degradation are reviewed. Fourthly, additives are discussed for melt stabilization of PLA. Although current literature reports the degradation reactions and clearly indicates the effect of degradation on PLA's properties, there are still knowledge gaps in how to select and predict the processing conditions that minimize process-induced degradation to save raw materials and time during production.

Enhancing the thermoplastic behavior and mechanical performance of recycledHDPE/CaCO3composites using oxidized polyethylene

AbstractThere is a growing interest in sustainable materials based on recycled or natural feedstocks for the circular economy. Ideally, thermoplastic materials are anticipated to show appropriate melt‐flow behavior for thermo‐mechanical recycling, good melt stability, and mechanical performance. Thermoplastic polyolefins such as polyethylenes are used as single‐use packaging materials and generate environmental concerns. This article reports the melt‐processing and characterization of composite materials based on recycled high‐density polyethylene (rHDPE) and naturally abundant calcium carbonate (CaCO3) mineral at various mass ratios such as 70/30, 50/50, and 30/70. Oxidized polyethylene (OPE) is used as an additive, with 20 wt% replacement of rHDPE, to improve the materials' mechanical performance and thermoplastic behavior. Various characteristics such as tensile, viscoelastic, melt‐flow, phase morphology, and thermomechanical recyclability of the materials are analyzed. It reveals that composites with high CaCO3content compatibilized with OPE show improved tensile strength and modulus. For example, the composite based on 10/70/20 (wt%) of rHDPE/CaCO3/OPE shows an average tensile strength of 27.4 MPa and Young's modulus of 4.5 GPa, in contrast to the rHDPE sample, which shows an average tensile strength of 12.4 MPa and Young's modulus of 967 MPa. Notably, adding OPE decreases the melt‐viscosity of the rHDPE/CaCO3materials, thus improving the composites' melt‐flow and thermoplastic behavior. This study indicates the possibility of developing natural CaCO3‐rich polymer composites with thermoplastic behavior for real‐life applications with superior mechanical and melt‐flow properties suitable for thermomechanical recycling.

Inorganic Filled Polycarbonate-Polybutylene Terephthalate Composites

A series of inorganic filled polycarbonate (PC) - polybutylene terephthalate (PBT) composites were prepared. The effects of various inorganic fillers, viscosity level of the PC and PBT resins, and also the blend ratio of PC to PBT, on the properties and stability of the composites were studied and are described. The results showed that the viscosities of PC and PBT had little impact on the mechanical properties of the composites. The melting stability of the composites was characterized by the difference of Melt Flow Index (△MFI) with composition, and it was found that the melting stability was improved significantly by using the resin (PC or PBT) of high viscosity as opposed to the medium one. With the increase of PC-to-PBT ratio, the increased Notched Izod Impact Strength of the composites and the reduced Melt Flow Index (MFI), Heat Deflection Temperature (HDT) and the density of the composites were observed. The “brittle-ductile transition” was found at various blend ratios of PC to PBT. The composition ratio of the critical point in this study was PC/PBT(45/30).

Understanding microstructure evolution and corrosion behavior of wire arc cladding inconel 625 Superalloy by thermodynamic approaches

Ni-based superalloys have excellent corrosion and oxidation resistance and are often used to make coatings on engineering components or steel materials. The free energy of the melt of Inconel 625 and multiple mixed Ni-based alloy were calculated by the optimized molecular interaction volume model (MIVM), and the cladding material composition is designed according to the composition - free energy curve. The corrosion resistance of the single and double deposited Ni-based layers with different Fe content were studied and compared. Potentiodynamic polarization and electrochemical impedance spectroscopy(EIS) analyses show that the corrosion resistance of the single deposited layers increases with the increase of Fe element, which Component is designed by thermodynamic calculation. Because of the thermodynamic stability of alloy melt is improved by the increase of Fe element, and reducing element segregation and formation of Laves phase. The pitting potential of the single deposited layer increase with the increase of Fe content, and the passivation film of the double deposited layers are more stable.

Thermal stability of emerging N6-type energetic materials: kinetic modeling of simultaneous thermal analysis data to explain sensitivity trends.

A number of new high-performing energetic materials possess explosophoric functionalities, high nitrogen content, and fused heterocyclic blocks. Two representatives of these materials have been synthesized recently, namely, 1,2,9,10-tetranitrodipyrazolo[1,5-d:5',1'-f][1,2,3,4]-tetrazine (1) and 2,9-dinitrobis([1,2,4]triazolo)[1,5-d:5',1'-f][1,2,3,4]tetrazine (2). The thermal stability of these energetic materials bearing the N-N-N = N-N-N fragment and three closely related compounds has been investigated for the first time. The thermal decomposition process of analyzed compounds was complicated by the appearance of the liquid phase, sublimation of the material, and autocatalysis by reaction products. In contrast to the traditional approach to the kinetic modeling based on data from either TGA or DSC, we use both signals' data measured at the same time and perform the joint kinetic analysis using the model-fitting technique to obtain the pertinent kinetic description of the process. Of the analyzed materials, 1 and 2 show the lowest thermal stability in melt with a characteristic rate constant of 2.6 × 10-3 s-1 at 250 °C. The kinetic parameters and calculated detonation performance data were used in the model to describe the mechanical sensitivity. The model output and the experimental friction sensitivity data show a respectable agreement, but more data are required to draw firm conclusions. In general, the provided thermal stability and kinetic data can be used for thermal response and storage modeling of these new N6-type energetic materials. The developed thermokinetic approach, joint model-fitting of several thermal analysis signals, can be applied to other complex thermally induced processes to increase the value and credibility of the kinetic findings.

Self-healing polyurethane-polypropylene oxide copolymers for the protection of carbon and glass fiber-reinforced composites

Polyurethane-polypropylene oxide block copolymers containing fragments of an adduct capable of self-healing by the Diels-Alder reaction mechanism have been synthesized and studied for the first time. All obtained polyurethane copolymers were characterized by IR spectroscopy. The temperature transitions and thermal stability of copolymer melts were determined by using the methods of differential scanning calorimetry and thermogravimetric analysis. The self-healing effect was confirmed using a thermal cycling procedure on pre-damaged samples of modified polyurethanes and surface morphology studies. The perspective of the work begun on the creation of self-healing protective polyurethane coatings are shown.