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The manuscript presents the latest data on the market of isocyanates, methods for producing their eco-friendly substitutes and the toxicity of the phosgene used in isocyanate production.

Non-isocyanate polyurethanes (NIPUs) constitute one of the most prospective groups of eco-friendly materials based on their phosgene-free synthesis pathway. Moreover, one of the steps of their obtaining includes the use of carbon dioxide (CO2), which allows for the promotion of the development of carbon dioxide capture and storage technologies. In this work, non-isocyanate polyurethanes were obtained via three-step synthesis pathway with the use of epichlorohydrin. In the I step, the addition reaction of epichlorohydrin with polyhydric alcohols was conducted for diglicydyl ethers obtaining. In the II step carbon dioxide reacted with diglicydyl ethers to obtain five-membered bis (cyclic carbonate)s in the cycloaddition reaction. Then, one-pot polyaddition reaction between bis (cyclic carbonate) and dimerized fatty acids-based diamine allowed for non-isocyanate polyurethanes (NIPU)s preparation. Three bio-based materials (two semi-products and one bio-NIPU) and three petrochemical-based materials (two semi-products and one NIPU) were obtained. The selected properties of the products of each step of NIPUs preparation were compared. Fourier transform infrared spectroscopy FTIR and proton nuclear magnetic resonance 1H NMR measurements allowed to verify the chemical structure of all obtained products. The average molecular masses of the semi-products were measured with the use of size exclusion chromatography SEC. Moreover, thermal stability and thermal degradation kinetics were determined based on thermogravimetric analysis TGA. The results confirmed that the activation energy of thermal decomposition was lower for semi-products and NIPUs prepared with the use of petrochemical-based epichlorohydrin than for their bio-based counterparts.

A considerable number of research works focus on the positive influence of cellulose on the properties of polymer-based composites and their wide range of application possibilities. The present work is focused on the synthesis of novel bio-based polyurethane (bio-PU) composites filled with powdered cellulose (microcellulose, MC) in an amount of 5 wt.%. Bio-PU composites were synthesized via a non-solvent prepolymer method. First, the prepolymer was synthesized from diisocyanate mixture based on hexamethylene diisocyanate and bio-based polyisocyanate Tolonate™ X Flo 100 and α,ω-oligo(ethylene-butylene adipate)diol which contained cellulose. Then, resulted prepolymer was extended by bio-based 1,4 butanediol (bio-BDO). Bio-PU composites were obtained with the different [NCO]/[OH] molar ratios: 0.95, 1.0, 105 and 1.1. Special attention was paid to the influence of MC on the phase separation between soft and hard segments of bio-PU by studying the chemical structure, morphology and thermal and mechanical properties of the prepared cellulose-based composites.

Application of bio-based diisocyanates with low volatility instead petrochemical diisocyanates has positive impact on environment by reduction of hazardous effects on living organisms and lead to bio-based polyurethanes (bio-PUs) with good usage properties. This work was focused on the synthesis and chosen properties examination of partially bio-based thermoplastic polyurethane elastomers (bio-PUs) obtained using diisocyanate mixtures, polytetrahydrofurane (PolyTHF) and bio-1,3-propanediol (bio-PDO). Two types of diisocyanate mixtures were prepared as follows: aliphatic-aliphatic based on hexamethylene diisocyanate with partially bio-based aliphatic diisocyanate Tolonate™ X FLO 100 (HDI-FLO) and aromatic-aliphatic based on diphenylmethane diisocyanate with partially bio-based diisocyanate (MDI-FLO) with reduction of 25 mass% of petrochemical diisocyanate. Bio-PUs were obtained via prepolymer method. Thermoplastic polyurethane elastomers have been examined in the terms of chemical structure and thermal, thermomechanical, mechanical and physicochemical properties. Bio-PU based on HDI-FLO diisocyanate mixture exhibited higher thermal stability. The beginning of thermal decomposition took a place at lower temperature ca. 30 ºC) and lower rate than the MDI-PU based materials. DMA analysis showed that HDI-FLO based polyurethanes exhibited greater capacity to accumulate energy and higher stiffness. Both materials characterized similar tensile strength and hardness, but with difference that TPU based on HDI-FLO relieved greater elongation at break about 360% reached 813%. Taking into account versatile properties of bio-TPU, these material can find application in many branches of industry.

Bio-based cyclic carbonates are of significant research interest as monomers for non-isocyanate polyurethane (NIPU) synthesis. This research describes the synthesis of a series of five-membered bis(cyclic carbonate)s using bio-based polyether polyols (PO3G) with different molecular weights (250, 650 and 1000 g mol−1) and carbon dioxide as green feedstocks. The utilization of CO2 as a source of carbon in the chemical reaction is in agreement with the sustainable chemical industry. Furthermore, in order to support the green and sustainable polymer chemistry approach, the syntheses were attempted under solvent-free conditions. The implemented synthetic methods are focused on the design of processes and final products that minimize negative environmental impact. Detailed chemical structure analysis of synthesized products was performed using a combination of spectroscopy techniques (ATR-FTIR as well as 1D and 2D NMR techniques), mass spectrometry (MALDI-TOF MS) and chromatography analysis (SEC). The formation of the main product with two terminal cyclic carbonates was confirmed and the formed side products were also identified, characterized and quantified. Finally, as a proof of concept, the synthesized bis(cyclic carbonate)s were successfully used for the preparation of NIPU thermosets. Chemical and mechanical properties of the produced materials suggest their high potential for future applications, e.g. as sound absorbing materials.

This work aimed to characterize the effect of the monomers chemical structure on the selected properties of the green thermoplastic poly(ether-urethane)s. During synthesis two types of polyether biopolyols, 4,4′-diphenylmethane diisocyanate and bio-based 1,3-propanediol were employed. Materials were synthesized with the use of two step method and two different prepolymers, which were mixed together in equimolar quantities. Obtained materials were characterized by spectroscopic method, size exclusion chromatography, thermal, static mechanical and melt flow index tests. It was confirmed that the prepolymers mixture has an effect on the thermal stability and selected properties of synthesized green thermoplastic poly(ether-urethane)s.

In response to the demand of polymer industry for reducing the use of synthetic chemicals, eco-friendly materials are investigated. In the presented study, bio-based poly(ether-urethane)s were prepared by using microcrystalline cellulose (MCC) and polyether polyol and 1,3-propanediol derived from corn sugar. A step towards sustainability was taken by incorporating bio-based compounds and cellulose, consequently, bio-waste are utilized in a smart way. The new materials were synthesized via prepolymer method, while the cellulose fibers were added after the reaction. Structural studies of biocomposites were realized by FTIR technique. The number of free and hydrogen-bonded carbonyl groups was determined based on the deconvolution of C=O band. Crystallinity was assessed on the basis of X-ray diffraction analysis. The influence of the MCC content on the thermo-mechanical, thermal and selected mechanical properties has been demonstrated. Results obtained by SEM method showed that the higher degree of reinforcement led to the formation of aggregates reflecting their poor dispersion in the polymer matrix. It may probably result from the relatively weaker interaction between MCC and PU matrix. On the other hand, it was found that the incorporation of fibers improved the thermo-mechanical and thermal properties of the prepared materials. This work provides an effective way of using bio-renewable chemicals in the polyurethane industry without using additional processing apparatus and chemical processes. The used method makes it possible to obtain materials with high bio-content and satisfactory thermal characteristic.

In this study, the effect of selected submicron metal oxide (zinc oxide, titanium oxide) or non-metal oxide (silicon dioxide) particles on mechanical and thermo-mechanical properties of epoxy/glass composites was investigated. The applied epoxy resin was a diglycidyl ether of bisphenol-A cured with triethylenetetramine. As a reinforcement twill weave E-glass fabric was used. Hybrid composites (contained particulate and fibrous filler) were fabricated by using the hand lay-up method and the average content of glass fibres was 39–41 wt%. Flexural properties, thermo-mechanical properties, abrasion resistance and hardness were determined for each group of the prepared hybrid epoxy/glass composites. The obtained results were compared with control samples (without submicron particles). Investigations showed that the addition of 2 wt% SiO2, 4 wt% TiO2 or 4 wt% ZnO to epoxy resin improved the flexural strength and the flexural modulus of composites. Dynamic mechanical analysis showed that the addition of the mentioned particles enhanced storage and loss modulus. It can be attributed to the good dispersion and good interaction between submicron-mentioned particles and the epoxy matrix.

The man aim of this work was to investigate the effect of the molecular weight of polyols, mixture of prepolymers, and [NCO]/[OH] molar ratio used during the prepolymer chain extending step on the chemical structure, thermomechanical and mechanical properties, and thermal stability of thermoplastic poly(ether-urethane)s In this work thermoplastic poly(ether-urethane)s were synthesized by using polyols with a various molecular weight, 4,4′-diphenylmethane diisocyanate and bio-based glycol. Materials were obtained by a two-step method. The tests were carried out for polyurethanes obtained from a mixture of prepolymers and for reference samples. In the case of materials obtained with using mixture of prepolymers, the ratio of both prepolymers was determined on 50/50 weight percent. Soft segments of materials prepared with using mixture consist of two different polyols. The chemical structure was analyzed using FTIR spectroscopy. The Gaussian deconvolution technique was used to study the hydrogen bonding as well as to decompose carbonyl region of three peaks in various TPUs. The thermal degradation behavior was investigated by using thermogravimetric analysis at heating rates of 10 °C/min. It was confirmed that the mixture of prepolymers has an effect of the degree of phase separation, thermal stability and selected properties of synthesized thermoplastic poly(ether-urethane)s.

In this study, the glycerolysis of polyurethane (PU) foam and the applicability of obtained glycerolysate (GLY) for cast PUs were investigated. It was found that crude glycerine with purity grade of 84% might be successfully used for the glycerolysis. The optimal conditions were determined as follows: reaction time of 60 min at 220 °C using dibutyltin dilaurate catalyst (0.5%). Moreover, the purification of GLY by means of liquid-liquid extraction and distillation was also adapted. Cast PUs based on GLY were prepared using a two-step method, during which a prepolymer was first synthesised from a mixture of virgin polyol, GLY and 4, 4′-diphenylmethane diisocyanate (MDI). The prepolymer was then extended with a chain extender, 1, 4-butanediol or 1, 3-propanediol. The effect of virgin polyol replacement by GLY (up to 75%) on thermal and mechanical properties of the cast PUs was determined. The PUs based on GLY exhibited slightly lower thermal stability, higher storage modulus and higher glass transition temperature than the neat PU. The tensile strength of all prepared PUs was beneficially high (12–15 MPa), while the elongation at break decreased with the increasing GLY content probable due to the branching of PU chains.

In this work the use of polyurethane chemical recycling product (i.e. glycolysis of polyurethane waste realized with the mass excess of polymer) as a plasticizer for natural rubber-based composites was proposed. The effect of plasticizer type (napthenic oil and polyurethane foam glycolysate) and amount (2, 4, 6 or 8 parts per 100 parts of natural rubber) on the processing properties of rubber mixtures and chemical structure, swelling, mechanical and thermo-mechanical properties of natural rubber/carbon black composites was investigated. The effect of applied plasticizer was studied in the context of accelerated thermal aging (thermo-oxidative aging) which was applied for the prepared natural rubber-based composites. The obtained results confirm that the polyurethane foam glycolysate can be successfully used as a plasticizer for the preparation of natural rubber composites. Moreover, it was found that glycolysate acts as a vulcanization accelerator and reduces decreasing of mechanical properties during the accelerated thermal aging.

Commercially available polyurethanes are synthesized by the polyaddition of diisocyanates with polyols and low molecular weight chain extenders. A new approach to polyurethanes synthesis is realize...

The main purpose of this work was to analyze the effect of the number of unreacted isocyanate groups and the [NCO]/[OH] molar ratio during the chain extension of a prepolymer during the polymerization process on the structure, processing and selected properties of thermoplastic poly(ether-urethane)s. Three series of novel thermoplastic polyurethanes were obtained via a prepolymer route. Three prepolymers were synthesized from diisocyanate and bio-based polyol, which contained 6, 7 and 8% of unreacted isocyanate groups. The prepolymer chains were extended by using bio-based 1,4-butanediol with four different [NCO]/[OH] molar ratios. It was confirmed that the concentration of unreacted isocyanate groups in the prepolymer has an effect on the degree of the hard segment phase separation of poly(ether-urethane)s. It was also found that the melt flow index has a significant impact on the processing of polyurethanes which can be correlated to the chemical structure and dynamic mechanical properties of the polyurethanes.

Recycled polymers and biopolymers are receiving a great deal of attention these days. If these two can be combined, it will lead to an environment-friendly green material with a great deal of applications. Here the present work is about incorporating bio-based fillers in a recycled polyurethane matrix. Two unusual and extremely novel sources of cellulose have been proposed. The celluloses obtained from Cissus latifolia and Ficus benghalensis were selected as sources. These sources have not been utilized and reported elsewhere to date. The cellulose modified samples of recycled polyurethane were analyzed using FTIR, scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) to have a preliminary idea about the combination. We found that these were successful as fillers in the matrix. The percentage of crystallinity was decreased in both the composites, which indicates the miscibility. Comparing the two sources, Cissus latifolia based cellulose was more effective in producing interesting morphologies and they had a percentage crystallinity of 75%, which was very high compared to all the reported works.

Liquid crystallinity was invented in the 19th century. It was sometimes called the fourth state of matter because of the ability of macromolecules to generate liquid crystal phases. The main classification divided liquid crystalline polymers (LCPs) into lyotropic and thermotropic types. Interpretation of the rheological behavior of LCP is more complicated than for other polymers. Ordinary polymers are characterized by a normal stress effect in shear flow, which always has a positive sign. There is a visible impact of temperature, solvents, plasticizers, the macromolecular structure, and the average molecular weight on the rheological behavior of LCPs. This chapter approximates and describes the most characteristic rheological behaviors of LCPs.

Polymer blends are physical mixtures of two or more homopolymers or copolymers. This type of materials have wide spectrum of technological applications, and their properties are influenced, e.g., by the properties of single components and morphology of final material. The rheology of polymer blends is connected with the processing of polymer blends and is influenced by thermodynamics, morphology, and their evolution during testing. This chapter provides an overview of research areas in the field of miscible and immiscible polymer blend rheology. Selected issues were discussed, e.g., application of time-temperature superposition principle in miscible polymer blends (concerning influence of intra- and intermolecular hydrogen bonding), influence of rheometer geometry on the obtained results, multiphase flow (including behavior of droplets in matrix), and flow imposed morphologies.

Linear bio-based polyester polyols were prepared with the use of succinic acid and 1,3-propanediol (both with natural origin). Tetraisopropyl orthotitanate (TPT) was used as a catalyst. In order to determine the effect of various synthesis temperature conditions on the thermal degradation kinetics, nine sequences of temperature conditions were used during two-step polycondensation reaction. Thermogravimetric analysis was conducted with the use of DSC-TG/QMS method (differential scanning calorimetry-coupled with thermogravimetry and quadrupole mass spectrometry). The results indicated high thermal stability of the obtained materials. They undergo a one-step thermal decomposition with the temperature of maximum rate of weight loss at ca. 405 °C. Moreover, the thermal degradation kinetics was determined with the use of Ozawa, Flynn and Wall as well as Kissinger methods. The highest thermal degradation activation energy was equal to 196.4 kJ/mol.

A new efficient method for the chemical decomposition of polyamide 6.6 by the glycolysis and amino-glycolysis processes was proposed. The glycolysis was conducted using the mass excess of ethylene glycol (EG) as a decomposing agent in the presence of a catalyst. Also, a mixture of EG and triethylenetetramine was used as another decomposing agent in the amino-glycolysis process. The described process of decomposition did not require the use of elevated pressure. The hydroxyl and amine numbers, rheology behavior and the presence of characteristic chemical groups in the obtained glycolysates and aminoglycolysates were determined in order to characterize the reaction products. The decomposition products were defined as non-Newtonian fluids that could be described by suitable mathematical models. The conducted studies showed that the properties of the obtained intermediates depend on the mass excess of the decomposing agent used. The resulting semi-products are suitable for reusing in the synthesis of polyurethanes, which has been confirmed by the exemplary synthesis. In the reaction, 10 and 15 wt% of commercial polyol were replaced with the recovered intermediates.

Currently, the increasing importance of the bio-based chemical compounds development is visible in the polymer chemistry, chemical engineering and materials science. It is well-known that the various purity level and different contaminants characterize petrochemical-based compounds compared to their bio-based counterparts. Therefore, it is necessary to find out the contaminants impact on the bio-based monomers synthesis. One of the most important information about the reaction pathway gave the kinetics study. In this work, the fully bio-based poly (propylene succinate)s were synthesized under various temperature conditions via two-step polycondensation reaction. The kinetics studies were investigated with the use of a functional group approach. The first step of the polycondensation reaction was autocatalytic esterification reaction. During the second step, the polycondensation catalyst was used. For macromolecular structure characteristics and the progress of the chemical reaction monitoring, Fourier Transform Infrared Spectroscopy, Proton Nuclear Magnetic Resonance, and Gel Permeation Chromatography were conducted. The activation energy value of 38.5 kJ/mol was determined for the first step of the bio-based polyols synthesis. The results of the investigations verified that the activation energy for the bio-based poly (propylene succinate) synthesis revealed lower value than the same polyester synthesis based on the petrochemical monomers. Thermal analysis by TGA measurements allowed confirmed the high thermal stability of the prepared bio-based polyols equaled ca. 418 °C.

Chemical recycling is the most favourable recycling method due to the possibility of polyol recovery. This work is dedicatedto the utilisation of crude glycerine and polyurethane waste. It aims at determining the impact of the use of glycerine fromthe production of biodiesel with various degrees of purity as a cleavage agent on the decomposition process of polyurethanefoam. The influence of glycerine purit y on the chemical structure of recycling products was analysed using Fourier transforminfrared and1H NMR spectroscopies and gel permeation chromatography. Hydroxyl and amine values were determined, andrheological measurements were performed. Glycerolysates showed minor structural differences due to the presence of aminegroups and exhibited heterogeneous structure compared to original polyols. The ones obtained in decomposition using 84and 99.5% glycerine had a lower viscosity below 0.45 Pa s at 50∘C and higher hydroxyl number of 183 and 220 mg KOH g−1,respectively, compared to the ones obtained with glycerine purity of 40 and 62% due to a different chemical struc ture. All ofthe products of decomposition were defined as non-Newtonian fluids, where viscosity depended on the shear rate. Selectedglycerolysates were used in the production of cast polyurethanes with satisfactory mechanical properties.

Our study was focused on obtaining polyetherurethanes synthesized with using polymeric polyether based polyols differing in dispersed copolymer content (10, 20 and 40 wt%). The polyetherurethane materials were synthesized via two step method. The influence of different polymeric polyether based polyols on the chemical structure, morphology, mechanical and thermal properties of the obtained polyetherurethanes was investigated. The Fourier transform infrared spectroscopy (FTIR) was used to analyze and confirm the chemical structure of synthesized materials. Analysis of thermal stability by thermogravimetric method (TGA) of polyetherurethanes indicated that the decomposition of all materials carried out in two steps. The results of the thermomechanical analysis (DMA) showed that the polyetherurethanes synthesized with using polymeric polyols containing 10 wt % of the copolymer characterized by the highest storage modulus of all materials. The same materials have got also the highest tensile strength value.

In the present paper, we have carefully investigated the morphology and fracture mechanism of the recycled polyurethane (RPU)/epoxy blend system. The second phase (RPU) added to the epoxy resin has a positive effect on the overall mechanical properties. Interestingly, the recycled polymer has a remarkable effect on the fracture toughness of epoxy resin. The mechanism behind the fracture toughness improvement up on the addition of RPU was found to be very similar to that of the incorporation of hyperbranched polymers in epoxy resin. Brittle to ductile fracture was clear in the case of higher loadings such as 20 and 40 phr of RPU in the epoxy resin. The mechanism behind improvement of fracture toughness was found to fibrillation of the RPU phase which was evidenced by the fracture morphology. In fact the force applied to the epoxy matrix was effectively transferred to the added RPU phase due to its strong interaction with the epoxy phase. This effective transfer of force to the RPU phase protects the epoxy matrix without catastrophic failure and we observed 44% increase in G1C values at an addition of 40 phr RPU. This results in the extensive fibrillation of RPU which causes the generation of new surfaces. Thus the impact energy has been fully utilized by the RPU phase. The mechanism is termed as simultaneous reinforcing and toughening and normally reported as a result of cavitations and yielding. SEM, HRTEM and AFM analyses clearly demonstrated the fibrillated morphology of the fracture surface and the formation of nanostructures. This report is first of its kind in the case of both epoxy modification and the elastomer toughening.

The synthesis of polyols from renewable substances as an alternative for petrochemical-based polyols play important matter in the polyurethane industry. In this work, the fully bio-based linear polyester polyols with different catalyst amounts were synthesized via two-step polycondensation method. The effect of various catalyst content on the structure and rheological behavior were established. Fourier Transform Infrared Spectroscopy, Nuclear Magnetic Resonance, Gel Permeation Chromatography and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry allowed confirming the impact of the catalyst amount during synthesis on the molecular structure of the resulted polyols. Through the hyphenation of these sophisticated polymer characterization techniques, information on the molecular weight distribution was obtained. Moreover, it was found that the obtained polyols are non-Newtonian fluids. According to conducted measurements, it was observed that the poly(propylene succinate)s prepared with the use of the 0.25 wt.% and 0.30 wt.% catalyst revealed the structures and selected properties the most akin to design.

One of the most important information about polyesters is their thermal stability and phase transition temperatures. These characteristics give information about the promising behavior of the polyester during processing. In this work, linear bio-based polyester polyols were prepared with the use of succinic acid and 1.3-propanediol (both with natural origin). As a polycondensation catalyst was used tetraisopropyl orthotitanate (TPT), which different amount was employed. The thermogravimetric analysis allowed to observe high thermal stability and one step of the thermal decomposition. This analysis affirmed also that the catalyst content did not influence the thermal degradation characteristics of the prepared polyols. Nevertheless, it has huge importance in the context of thermal degradation kinetics. It was determined with the use of Ozawa, Flynn, and Wall and Kissinger's methods to verifying catalyst impact on the thermal degradation kinetics. Moreover, probable mechanism of the prepared bio-based polyols thermal degradation was proposed based on the QMS results.

This paper aims at the utilisation of glycerolysate (Gly) obtained in polyurethane recycling process by means of crude glycerine, which has in its structure hydroxyl end groups that allow for further processing. Polyurethanes (PUs) were synthesised using prepolymer method with the mixture of neat polyol and glycerolysate, in different ratios, with 4,4-diphenylmethane diisocyanate (MDI). The prepolymer was subsequently extended using 1,4-butanediol (BD). The incorporation of glycerolysate caused the crosslinking of obtained polyurethane materials. The crosslink density was calculated from swelling measurements by means of Flory and Rehner equation. The effect of recycled component content on the structure, thermal and mechanical properties were investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and mechanical tests, respectively. Morphology was also analysed by atomic force microscopy (AFM). As the content of recycled component increased, the swelling ratio decreased and simultaneously crosslink density increased, resulting in the increase of glass transition and storage modulus at room temperature. Thermomechanical stability, tensile strength, elastic modulus and hardness of PUs also increased with the incorporation of glycerolysate. Although elongation at break decreased, the recoverable deformation increased with the content of glycerolysate. Morphology reveals the transition from a microphase-separated microstructure to an interconnected hard segments domain structure with the incorporation of glycerolysate. These materials can be applied as protective coatings.

The aim of this work was to investigate the influence of Spirulina (Spirulina platensis) as a natural filler on the curing characterization, morphology and mechanical, thermomechanical and thermal properties of natural rubber (NR) based composites. Spirulina was introduced into NR mixture in amount of 0 phr, 10 phr and 30 phr. The vulcanization process was carried out at the determined process condition by using hydraulic press at optimum vulcanization time (t90). It was noticed that Spirulina affected on the reduction of t90, and scorch time (t2) of the NR mixtures. Obtained vulcanizates were subjected to the number of tests e.g. scanning electron microscopy analysis, mechanical dynamical analysis, tensile test, hardness, and thermogravimetry. Generally, it was found that Spirulina added in amount of 10 phr NR positively influenced on tensile strength (TSb), storage modulus and hardness of obtained composites.

Correction for ‘Synthesis and structural characterization of bio-based bis(cyclic carbonate)s for the preparation of non-isocyanate polyurethanes’ by Kamila Błażek et al., Polym. Chem., 2021, DOI: 10.1039/d0py01576h.

The application of thermoplastic polyurethanes (TPU) is becoming more and more extensive, and the decreasing of used petrochemical monomers and reduction of energy for the polymerization and processing processes is getting increasingly important. In this paper, we confirmed the positive influence of high bio-based monomers contents (by replacing petrochemical polyol and glycol by bio-based counterparts) on processing and properties of obtained materials. A series of partially bio-based thermoplastic poly(ether-urethane)s (bio-based TPU) were obtained from bio- and petrochemical-based polyols, bio-based 1,4-butanediol, and 4,4′-diphenylmethane diisocyanate by the two-step method without using any solvents. Both the monomers’ origin and polyurethane prepolymer processing parameters were taken into account in characterization of the obtained materials. The TPUs' chemical structure was analyzed by FTIR spectroscopy and 1H NMR and the number average molecular weight was examined by 1H NMR and GPC. The measurements of dynamic mechanical thermal analysis, tensile test, hardness, density method, and rheological behavior provided useful information about the properties of prepolymers and TPUs. The processing properties and an activation energy of prepared materials was examined using the melt-flow index. It has been confirmed that despite the origin of polyols obtained thermoplastic poly(ether-urethanes) exhibited comparably good mechanical and thermo-mechanical properties, and an appropriate melt flow index facilitates their processing. Nevertheless, the use of high amount of bio-based monomers resulted in obtaining more eco-friendly materials.

Polyurethanes are among the most developed types of polymers. They are produced from the three primary components, i.e., polyols, low-molecular-weight glycols used as chain extenders, and diisocyan...

The polyol is a major component in polyurethane formulations and therefore introducing to the formulation recycled polyol (obtained during decomposition process) allows decreasing the usage of pure petrochemical components. In this work, thermoplastic polyurethanes were prepared using various mixtures of a petrochemical macrodiol poly(ethylene-butylene adipate)diol (PEBA) and a recycled glycolysate intermediate, called glycolysate polyol, in a two-step synthesis procedure with 4,4-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BD). The glycolysate polyol was obtained during glycolysis process of polyurethane elastomer using ethylene glycol as a decomposing agent. Glycolysate polyol showed a higher hydroxyl value (199 mg KOH g−1) and glass transition temperature (Tg, −50.1 °C) than pure macrodiol (PEBA). The maximum concentration of glycolysate polyol was 25 wt% over the total polyol. Synthesized polyurethanes had similar chemical structure compared to the polyurethane synthesized without glycolysate polyol, confirmed by Fourier transform infrared spectroscopy. On the one hand, higher contents of glycolysate polyol resulted in higher Tg and a slightly lower thermal stability analyzed by thermogravimetric analysis. On the other hand, improved thermomechanical and mechanical properties were obtained in polyurethanes with partial replacement of pure macrodiol.

Zbadano mozliwości zastosowania glikolizatu, otrzymanego w reakcji dekompozycji odpadowej pianki obuwniczej z etano-1,2-diolem, do otrzymania poliuretanu w postaci plytek oraz podeszew zawierających 2 i 3,2% mas. glikolizatu. Otrzymany glikolizat mieszano z konwencjonalnym poliolem. Zbadano wlaściwości reologiczne i strukture chemiczną glikolizatu oraz zsyntetyzowanych poliuretanow za pomocą spektroskopii w podczerwieni (FTIR). Oznaczono tez wytrzymalośc na rozciąganie, twardośc oraz gestośc. Podeszwy zostaly zbadane pod kątem odporności na wielokrotne zginanie, ścieralnośc oraz adhezje lakieru. Stwierdzono, ze glikolizat moze byc stosowany w niewielkiej ilości do otrzymania eco-podeszwy spelniającej wymogi norm.

In this paper, the poly(ester-urethane)s obtained using petrochemical and bio-based chain extenders were prepared and characterized. The influence of glycols’ origin on the chemical structure, mechanical and thermal properties of the prepared polyurethanes was studied. The materials were synthesized by prepolymer method. The first step involved the reaction of α,ω-dihydroxy(ethylene-butylene adipate) (POLIOS 55/20) with 4,4′-diphenylmethane diisocyanate (MDI). In the next step, obtained prepolymer terminated with isocyanate group was extended using 1,3-propanediol and 1,4-butanediol at three different molar ratios of NCO group (presented in prepolymer chains) to OH groups (presented in chain extender structure), i.e., 0.95, 1.0 and 1.05. The results showed that applying the different types (diversified chemical structure and origin) of glycols results in obtaining materials with diversified mechanical properties and slight different thermal stabilities. The results of Fourier transform infrared spectroscopy showed that the chemical structure of the obtained polyurethanes was not affected by the presence of glycols with the same chemical structure and different origins (petrochemical and bio-based nature).

In this work, the effect of the high molecular weight bio-based diamine on the chemical structure and selected properties of poly(ether-urethane-urea)s has been investigated. The ether-urethane prepolymer was cured using 1,4-butanediol and/or bio-based diamine. Mentioned chain extenders were used separately or in the mixture, and their different molecular weight and chemical structure resulted in obtaining materials with diversified mechanical performence. The presence of specific chemical groups (i.e. urethane and urea groups) was confirmed by FTIR method. For the synthesized poly(ether-urethane-urea)s morphology and fracture mechanism, thermo-mechanical properties and mechanical properties were determined and discussed. Results confirmed that bio-based diamine acts as soft segments, and this is connected with changing of mechanical and thermo-mechanical properties of prepared partially bio-based poly(ether-urethane-urea)s. The increasing content of bio-based diamine resulted in increasing of tensile modulus and decreasing of tensile strength and elongation at break, and this is resulted from chemical structure of bio-based diamine (i.e. presence of aliphatic side chains).

Effect of plasticizer type on the kraft lignin–natural rubber composite microstructure and selected properties was determined. The composites were prepared with addition of a commonly used naphthenic oil plasticizer to study the decomposition product of polyurethane (glycerolysate) and its characteristics. Kraft lignin powder was incorporated into the natural rubber matrix in amounts of 10 and 40 parts per 100 parts of natural rubber (phr). The reference samples were prepared without any lignin present. The chemical interaction between the filler particles and natural rubber macromolecules was analyzed by Fourier transform infrared spectroscopy (FTIR) and the adhesion was characterized by scanning electron microscopy (SEM). The results of the adhesion measurements confirmed poor distribution of lignin particles into the natural rubber matrix with increasing filler content. Optimal lignin content in the composites was 10 phr in the case of both plasticizers. Moreover, the results of FTIR verified the formation of non-covalent bonds and the need for modification of the filler to enhance the reinforcing effect in the natural rubber matrix. Dynamic mechanical analysis (DMA) and mechanical measurements proved that the specimen containing 10 phr of lignin with the use of glycerolysate as plasticizer displayed the highest mechanical performance. It was demonstrated that glycerolysate and naphthenic oil as plasticizing agents showed similar effect on the thermal properties of the prepared composites. Also, the measured mechanical properties, such as tensile strength, hardness, resilience, and abrasiveness confirmed these findings.

A novel and cost-effective approach towards the modification of epoxy matrix has been developed using recycled polyurethane for the first time without sacrificing any of the intrinsic properties of the resin. Polyurethane, recycled from waste foam by glycolysis process (RPU), was found to be very effective in improving the properties of the thermosetting resin based on Diglycidyl ether of bisphenol-A (DGEBA). The effect of the addition of polyurethane on the mechanical and viscoelastic properties was analyzed and the morphological changes with the inclusion of varying concentrations of RPU were examined by High Resolution Transmission Electron Microscopy (HRTEM). All the blends remained transparent, even after curing by a reaction induced phase separation process (RIPS) of the epoxy phase and hence suggests the development of microphase separation and nanostructure formation. The nanoscale morphology is very clear even with 15 phr concentration of the recycled polyurethane. The morphology at high concentration (40 phr) of RPU under HRTEM showed very distinct ordered interpenetrating network (IPN) like formation and a phase in phase morphology. The size of the dispersed RPU particles varied from 32 to 80 nm as the concentration of RPU varied from 15 to 40 phr in the epoxy phase. This is the first report where nanoscale morphology development by viscoelastic phase separation (VPS) process. The tensile strength values varied from 57 MPa for neat epoxy to 68 MPa for the 40 phr blend. The fracture toughness was increased by 83% for the addition of 40 phr RPU. The recycled PU can be considered as excellent low cost reinforcing filler for epoxy resin where strength and modulus of epoxy resin could be improved simultaneously with an increase of fracture toughness.

Linear bio-based polyester polyols were prepared with the use of succinic acid and 1.3-propanediol (both with natural origin). As a catalyst was used tetraisopropyl orthotitanate (TPT). In order to determine the effect of various catalyst content on the thermal degradation characteristics, three different TPT amounts, as a 1.3-propanediol equivalent, were used, namely 0.1 mass% (PPS-0.1), 0.2 mass% (PPS-0.2) and 0.25 mass% (PPS-0.25). The reference polyol was prepared without catalyst employment (PPS-0.0). Fourier transform infrared spectroscopy was used to confirm molecular structure of the resulted polyols. The structure was also corroborated by 1H NMR measurements, what confirmed nonsignificant catalyst amount impact on the structure of the prepared polyester polyols. Differential scanning calorimetry was carried out for glass transition temperature and melting point determination. The thermogravimetric analysis allowed to observe high thermal stability both under inert and oxidative atmosphere. This analysis affirmed also that the catalyst content did not influence significantly on the thermal degradation characteristics of the prepared polyols.

This work is mainly focused on study of thermal and thermomechanical properties of obtained bio-based polyurethane (coded as bio-PU) composites via using different types of bio-components (bio-glycol, modified soybean oil and sisal fiber) in the procedure. The chemical structure, morphology and mechanical properties were also investigated and described in this manuscript in order to know more perfect characterization of produced composites. The bio-based polyurethane matrix of composites was synthesized via prepolymer method. Bio-PU composites were produced by dispersing 5 and 15 mass% of sisal fibers into the polyurethane matrix during their synthesis. To investigate the thermal stability of sisal fibers and bio-PU composites, the thermogravimetric method (TG) was used. Thermomechanical tests were performed by means of dynamic mechanical analysis (DMA). Based on the results of thermomechanical analysis, it was found that the sisal fibers amount has the impact on storage and loss modulus. Chemical structure was confirmed by FTIR spectra. Mechanical results and scanning microscopy images of the composites showed good interfacial adhesion between sisal fibers and the bio-based PU matrix.

Due to the increasing amount of polyurethane waste, chemical recycling of these materials is a topic of growing interest for many researchers. The primary purpose of polyurethane feedstock recycling is to recover the starting polyol. In this study glycerolysis using glycerine from two sources and two purity grades is proposed as a method of chemical recycling. The main effort of this paper focuses on the employment of commercial glycerine of analytical grade and waste glycerine without purification derived from the biodiesel production, as a decomposing agent for polyurethane recycling. In this study, the influence of polyurethane to glycerine mass ratio (PU/GL) and the type of decomposing agent on the chemical structure by FTIR, 1H NMR and GPC was examined. FTIR analysis of the glycerolysates showed absorption peaks similar to the virgin polyol. Those results are in compliance with GPC chromatograms, which showed for all samples, well-defined peak at ca. 13 min of retention time. The molecular weight of glycerolysates was ranging from 800 to 1300 g mol−1 depending on PU/GL mass ratio. The novel decomposition agent, namely waste glycerine derived from biodiesel production was successfully used in glycerolysis process.