Rigid Polyurethane Foam Research Articles

Rowanberry/vermiculite modified rigid polyurethane foams

Rigid polyurethane (PU) foams were modified with rowanberry/vermiculite fillers. The impact of fillers on selected properties of composites, such as rheological properties (dynamic viscosity, foaming behavior), mechanical properties (compressive and flexural strength, toughness), thermal properties (temperature of thermal decomposition stages, char residues at 600°C), flame retardancy (ignition time IT, total heat, and smoke release THR and TSR, maximum average rate of heat emission MARHE) was investigated. The results show that the incorporation of rowanberry/vermiculite fillers improves the properties of polyurethane foams. For instance, compared with the reference foam, modified foams showed increased synthesis times and higher values of apparent density, which then influenced the mechanical properties. Compared to the unmodified foam, modified foams showed an improvement in compressive strength (up to 7.8%, measured parallel to the foam growth direction), flexural strength (up to 5.8%), and toughness (up to 6.8%). Most importantly, the modified foams showed improved thermal stability and flammability parameters such as elongated ignition time, lowered values of THR, TSR, and MARHE parameters.

Manufacturing and properties of epoxy-basalt fiber laminates filled with waste rigid polyurethane foam for structural and damping applications

Manufacturing and properties of epoxy-basalt fiber laminates filled with waste rigid polyurethane foam for structural and damping applications

Disposal of rigid polyurethane foam with fly ash as a method to obtain sustainable thermal insulation material

The high cost of fossil raw materials is leading to the partial replacement of polyurethane raw materials with solid fillers. A promising modifier is fly ash (FA) added to rigid polyurethane foam (PUR) at 10 wt%. An unsolved problem concerns the recycling of this material. Therefore, in the present study, composites of PUR were produced with 2.5, 5.0 and 7.5 wt% shredded foam containing 10 wt% of FA. The paper presents the results of apparent density, morphology and thermal conductivity of obtained materials. Furthermore, the results of the hot plate test were presented. The addition of the filler resulted in a reduction in cell diameter and partial opening of the cells. As the filler concentration increased, there was an increase in density and thermal conductivity. The highest coefficient value was obtained for PUR+ 7.5%PUR and was 0.0037 W/(m⋅K). The effect of the shredded foam added to the new polyurethane system on the thermal conductivity coefficient was confirmed in the hot plate test, with the PUR+ 7.5% PUR sample achieving the highest surface temperature and the PUR the lowest. As part of the comparison of insulation properties, numerical calculations of the heat demand were carried out for a partition built with the materials received and pure foam. For a house with walls insulated with a 15 cm layer of PUR, the annual energy demand is 11.30 kWh/(m2·year), for PUR+ 2.5%PUR it is 11.59 kWh/(m2·year), for PUR+ 5.0%PUR it is 12.46 kWh/(m2·year), and for a wall with PUR+ 7.5%PUR it is 13.55 kWh/(m2·year).

Balanced Thermal Insulation, Flame-Retardant and Mechanical Properties of PU Foam Constructed via Cost-Effective EG/APP/SA Ternary Synergistic Modification.

To address the challenge of balancing the mechanical, thermal insulation, and flame-retardant properties of building insulation materials, this study presented a facile approach to modify the rigid polyurethane foam composites (RPUFs) via commercial expandable graphite (EG), ammonium polyphosphate (APP), and silica aerogel (SA). The resulting EG/APP/SA/RPUFs exhibited low thermal conductivity close to neat RPUF. However, the compressive strength of the 6EG/2APP/SA/RPUF increased by 49% along with achieving a V-0 flame retardant rating. The residual weight at 700 °C increased from 19.2 wt.% to 30.9 wt.%. Results from cone calorimetry test (CCT) revealed a 9.2% reduction in total heat release (THR) and a 17.5% decrease in total smoke production (TSP). The synergistic flame-retardant mechanism of APP/EG made significant contribution to the excellent flame retardant properties of EG/APP/SA/RPUFs. The addition of SA played a vital role in reducing thermal conductivity and enhancing mechanical performance, effectively compensating for the shortcomings of APP/EG. The cost-effective EG/APP/SA system demonstrates a positive ternary synergistic effect in achieving a balance in RPUFs properties. This study provides a novel strategy aimed at developing affordable building wall insulation material with enhanced safety features.

Grafting modification bamboo kraft lignin and its performance in rigid polyurethane foams

AbstractIn order to improve the efficiency of intumescent flame retardant (IFR), bamboo kraft lignin (BKL) was chemically functionalized by grafting melamine (MEL) and diethyl phosphite (DEP) and used for rigid polyurethane (RPU) foam. The BKL, MEL, and DEP in IFR system were used as char forming agent, gas, and acid source, respectively. The FTIR and XPS results indicated that the nitrogen (N) and phosphorus (P) containing BKL was successfully synthesized. The limiting oxygen index (LOI) value of N‐BKL and N/P‐BKL RPU foams were higher than BKL RPU foam, suggesting that N‐BKL and N/P‐BKL improved flame retardancy of the foams. The total heat release (THR), heat release rate (HRR), effective heat of combustion (EHC), and fire growth rate (FIGRA) values of N‐BKL and N/P‐BKL RPU foams were much lower than that of BKL RPU foam. The flame retardancy index value of N/P‐BKL RPU foams was higher comparing to N‐BKL RPU foam. These results indicated that the synergistic interaction between N containing compound of MEL and P containing compound of DEP led to the improvement flame retardant properties. Comparing to BKL RPU foam, the N/P‐BKL RPU foam increased 74°C of maximum weight loss temperature and decreased 18.1 wt% of mass loss, indicating enhanced thermal stability. The morphology of char after cone calorimeter testing showed the N/P‐BKL RPU foam presented more continuous and compact char residues, which could reduce heat and mass transfer, protecting underlying materials from further combustion in a fire, thus resulting in good flame retardancy and thermal stability properties. This work suggests a promising route to enhancing the flame‐retardant performance of RPU foam using nontoxic and more environmentally friendly grafted bamboo lignin.

Elaboration of Thermally Performing Polyurethane Foams, Based on Biopolyols, with Thermal Insulating Applications.

In this work, biobased rigid polyurethane foams (PUFs) were developed with the aim of achieving thermal and fireproofing properties that can compete with those of the commercially available products. First, the synthesis of a biopolyol from a wood residue by means of a scaled-up process with suitable yield and reaction conditions was carried out. This biopolyol was able to substitute completely the synthetic polyols that are typically employed within a polyurethane formulation. Different formulations were developed to assess the effect of two flame retardants, namely, polyhedral oligomeric silsesquioxane (POSS) and amino polyphosphate (APP), in terms of their thermal properties and degradation and their fireproofing mechanism. The structure and the thermal degradation of the different formulations was evaluated via Fourier Transformed Infrared Spectroscopy (FTIR) and thermogravimetric analysis (TGA). Likewise, the performance of the different PUF formulations was studied and compared to that of an industrial PUF. From these results, it can be highlighted that the addition of the flame retardants into the formulation showed an improvement in the results of the UL-94 vertical burning test and the LOI. Moreover, the fireproofing performance of the biobased formulations was comparable to that of the industrial one. In addition to that, it can be remarked that the biobased formulations displayed an excellent performance as thermal insulators (0.02371-0.02149 W·m-1·K-1), which was even slightly higher than that of the industrial one.

Epoxy lignin-modified tetraethylenepentamethylene-CO2 halogen-free blown rigid polyurethane foam

A new halogen-free blowing agent for rigid polyurethane foam, E-Lig-TEPA-CO2, was synthesized by absorbing CO2 onto tetraethylenepentamine modified with epoxy lignin. The blowing agent was modified with lignin, which introduced hydrophobic groups such as benzene rings, carbon chains, and aromatic ethers. This modification enhanced its oil affinity and compatibility in the polyol mixture. Surface tension testing showed that the surface tension of the lignin-modified blowing agent decreased from 36 to 24 mN/m. Observations through Olympus microscopy revealed that the lignin-modified blowing agent was better dispersed in the polyol mixture, with fewer air bubbles and improved compatibility. Additionally, the main raw material used for this blowing agent was low molecular weight tetraethylenepentamine, resulting in a liquid-state blowing agent. This liquid-state blowing agent inherently possessed advantages in terms of dispersibility and compatibility compared to solid-state blowing agents. Finally, self-made lignin phosphate (P-Lig), expandable graphite (EG), and dimethyl methyl phosphonate (DMMP) were added as halogen-free flame retardants. Lignin-bio-based polyol was used as partial polyol. A new type of bio-based and halogen-free blown flame-retardant rigid polyurethane foam was prepared. The resulting foam demonstrated small and evenly distributed cell structures, as well as good compression strength (224 kPa) and thermal conductivity (0.029 W/(m·k)). The limiting oxygen index of foam increased to 30.6%, reached the V-0 level during the vertical burning process, the peak heat release rate decreased to 196 Kw/m2, and high-temperature thermal stability in thermogravimetric was enhanced.

Long-Service-Life Rigid Polyurethane Foam Fillings for Spent Fuel Transportation Casks.

Soft materials bearing rigid, lightweight, and vibration-dampening properties offer distinct advantages over traditional wooden and metal-based fillings for spent fuel transport casks, due to their low density, tunable structure, excellent mechanical properties, and ease of processing. In this study, a novel type of rigid polyurethane foam is prepared using a conventional polycondensation reaction between isocyanate and hydroxy groups. Moreover, the density and size of the pores in these foams are precisely controlled through simultaneous gas generation. The as-prepared polyurethane exhibits high thermal stability exceeding 185 °C. Lifetime predictions based on thermal testing indicate that these polyurethane foams could last up to over 60 years, which is double the lifetime of conventional materials of about 30 years. Due to their occlusive structure, the mechanical properties of these polymeric materials meet the design standards for spent fuel transport casks, with maximum compression and tensile stresses of 6.89 and 1.37 MPa, respectively, at a testing temperature of -40 °C. In addition, these polymers exhibit effective flame retardancy; combustion ceased within 2 s after removal of the ignition source. All in all, this study provides a simple strategy for preparing rigid polymeric foams, presenting them as promising prospects for application in spent fuel transport casks.

Synthesis of MXene-Based functional coatings on rigid polyurethane foam surfaces: A comparative study of layer-by-layer self-assembly and hydrothermal methods

A flame retardant for rigid polyurethane (RPUF) was designed and synthesized to expand the application field of RPUF. The flame retardants, namely MXene/PEI/PA-L and MXene/PEI/PA-H, were synthesized using phytic acid (PA), polyethyleneimine (PEI), and MXene through layer-by-layer (LBL) self-assembly method and hydrothermal method, respectively. In terms of mechanical performance, MXene/PEI/PA-L imparted brittleness to RPUF while MXene/PEI/PA-H enhanced its toughness, enabling RPUF to adapt to diverse application scenarios. The flame retardant properties were evaluated via vertical combustion test, cone calorimetry test, and thermogravimetric test, and the gas phase flame retardant mechanism was analyzed by TG-FTIR. MXene/PEI/PA constituted a N-P-Ti synergistic flame retardant system. During combustion, MXene/PEI/PA formed a layered dense carbon layer to cut off the external oxygen transport channel and absorbed many oxygen-containing free radicals. MXene/PEI/PA-L demonstrated efficient smoke suppression capability, while MXene/PEI/PA-H showed superior thermal insulation performance. The ignition time (TTI) of the composite foam reached 47 s, the total smoke release (TSR) value decreased by 92 %, and the flame retardant grade reached 5VA. Coated RPUF had excellent flame retardant ability.

Investigating the potential of dihydroxystearic acid as feedstock for rigid polyurethane foam

Rigid polyurethane (PU) foam has been widely used for a multitude of applications, primarily as thermal insulation materials. With the exhortation of “green chemistry” and sustainable development, bio-based polyols are being introduced to replace the conventional petrochemical-based polyols. Hence, the use of 9, 10-dihydroxystearic acid (DHSA), derived from palm oil-based oleic acid, as a feedstock for rigid PU foam production was explored. In this study, the effects of the weight ratio percentage of DHSA on the characteristics of the resulting PU foams were investigated. The DHSA was utilized as a co-polyol to synthesize rigid PU foams by reacting with the diisocyanate compound, blowing agent and additives. In general, the effects of DHSA in the formulations on the quality of the foams were relatively similar to PU formulation without the addition of DHSA, particularly in terms of density, compressive strength, thermal conductivity, cell structure and dimensional stability. The remarkable effect of DHSA addition in the PU formulations was observed through the open PU cell content using a pycnometer and scanning electron microscopy (SEM). The addition of DHSA has the ability to open the cell structure of the resulting rigid PU foams. The open cell content increased notably from 6.83% to 90.99% when the DHSA content was increased from 0% to 50%. The ability of DHSA to produce open-cell rigid PU foam widens up the potential applications of rigid PU foams as sound absorption materials.

Synthesis and characterization of rigid water-blown, palm oil-based polyurethane/organically-modified clay nanocomposite foam

Despite the superior enhancement it could impose, incorporation of montmorllonite (MMT) nanoclay in polymer-matrix composites is still limited due to miscibility issues with its host matrix; which could be alleviated with surface-modification of the nanoclay. In this paper, diamino methylpentane-modified montmorillonite (DAMP-MMT) nanoclay was incorporated into a bio-based polyurethane (PU) foam at different weight loadings. Characterization tests were then carried out to investigate the influence of included organoclay on the mechanical properties, thermal stability, foam morphology, and foaming kinetics. MMT modification effect could clearly be observed with exfoliated microstructure at lower loadings, compared to pristine clay at similar loading. Presence of organic modifier tethered on the surface of nanoclay was found to act as catalyst which induced accelerated curing, affecting cellular size and structure of foam, which in return cascades into influencing mechanical and thermal properties of the foam. Compressive strength improved with addition of 1 wt.% clay, and deteriorated beyond this point; believed due to clay agglomeration at higher clay loadings. However, thermal stability showed improvement parallel with its clay content, believed owed to additional bonds formed between amine -NH2 from organoclay and – NCO from diisocyanates. Incorporation of organoclays in rigid bio-based PU foam shows great potential in moderate load-bearing applications while upholding “green chemistry” practice.

Pyrolytic lignin fractionation for rigid polyurethane foams: Relationship between the Pyrolysate's chemical structure and foam properties

Pyrolytic lignin (PL) has emerged as a promising renewable material for the production of polyurethanes (PU) due to the high concentration of hydroxyl groups in its structure, being a potential substitute for petroleum-based polyols. On one hand, the high functionality and liquid form of PL favor its application as a polyol in PU formulations. On the other hand, the inherent heterogeneity of PL still imposes a challenge for the development of new materials with reproducible properties. In this work, aiming to overcome these limitations, an acetone-water fractionation process was successfully used to fractionate PL. The resulting fractions were analytically characterized by HSQC NMR, 31P NMR and rheological analysis, revealing significant structural and compositional differences. Afterwards, these fractions partially replaced an industrial polyether polyol in the formulation of rigid PU foams. Finally, microstructure and mechanical properties of these foams were evaluated by SEM and uniaxial compressive tests. The lignin-based foams exhibited reduced cell size and improved mechanical properties compared to the reference foam (based on a polyether polyol). Thus, the mechanical properties of PU foams can be enhanced through the selection of specific PL fractions. These results highlight the potential of PL fractions as a sustainable and viable alternative to industrial polyols for PU foams with improved properties.

A comparative study of polyurethane foam by substituting LBA using green polyurethane foam CFA‐1

AbstractPolyurethane foams are well‐known optimal thermal‐insulating materials, which have good thermal insulation performance, high strength, and lightweight properties. Here, we describe a chlorine‐free and fluorine‐free polyurethane chemical foaming agent (CFA‐1) that can react with isocyanate to release CO2 gas and foam polyurethane. We systematically studied its application performance in the field of polyurethane spraying by substituting the current most advanced and environment‐friendly physical foaming agent 1‐chloro‐3,3,3‐trifluoroprop‐1‐ene in different proportions. The results show that highly competitive mechanical properties lead to economical, environment‐friendly, and efficient features. The lower thermal conductivity, more compact and smaller bubble structure, and excellent compression strength were achieved by tuning the proportion of CFA‐1 from 20% to 60%. Thus, a promising material system was established for the development of the rigid polyurethane foam industry.

Effect of bio-polyol molecular weight on the structure and properties of polyurethane-polyisocyanurate (PUR-PIR) foams

The increasing interest in polyurethane materials has raised the question of the environmental impact of these materials. For this reason, the scientists aim to find an extremely difficult balance between new material technologies and sustainable development. This work attempts to validate the possibility of replacing petrochemical polyols with previously synthesized bio-polyols and their impact on the structure and properties of rigid polyurethane-polyisocyanurate (PUR-PIR). To date, biobased polyols were frequently used in the manufacturing of PU, but application of bio-polyols synthesized via solvothermal liquefaction using different chains of polyethylene glycol has not been comprehensively discussed. In this work, ten sets of rigid polyurethane foams were synthesized. The influence of bio-polyols addition on foam properties was investigated by mechanical testing, thermogravimetric analysis (TGA), and cone calorimetry. The structure was determined by scanning electron microscopy (SEM) and a gas pycnometer. The tests revealed a significant extension of foam growth time, which can be explained by possible steric hindrances and the presence of less reactive secondary hydroxyl groups. Moreover, an increase average size of pores and aspect ratio was noticed. This can be interpreted by the modification of the cell growth process by the introduction of a less reactive bio-polyol with different viscosity. The analysis of foams mechanical properties showed that the normalized compressive strength increased up to 40% due to incorporation of more cross-linked structures. The thermogravimetric analysis demonstrated that the addition of bio-based polyols increased temperature of 2% (T2%) and 5% (T5%) mass degradation. On the other hand, evaluation of flammability of manufactured foams showed increase of total heat release (HRR) and smoke release (TSR) what may be caused by reduction of char layer stability. These findings add substantially to our understanding of the incorporation of bio-polyols into industrial polyurethane systems and suggest the necessity of conducting further research on these materials.

Preparation and characterization of phase change material microcapsules with carbon nanotubes loaded with Mg[sbnd]Al layered double hydroxides for controlling temperature in the building

Tubular structure embedding technique has promising applications in improving the thermal conductivity of phase change material microcapsules (PCMM). In this paper, the carbon nanotubes (CNT) were pretreated with flame retardant using magnesium‑aluminum layered double hydroxide (LDH) by co-precipitation method and then embedded in the shell of microcapsules. Thus, a phase change material microcapsule with both temperature control capability and flame retardancy was prepared. The microcapsules used capric acid (CA) as the core and polymethyl methacrylate (PMMA) as the shell, and the particle size was 100 nm-1 μm. The successful composition of the samples was verified by TEM and FT-IR. DSC test proves that CNT and LDH-modified CNT have very positive performance in improving the thermal conductivity of microcapsules. The outcome of TGA analysis and cone calorimeter test showed that the incorporation of modified PCMM into the rigid polyurethane foam (RPUF) matrix had a significant effect on improving its thermal stability and flame retardancy. The infrared thermal image analysis and self-created mini-chamber model were set up to characterize the temperature control performance of the sample. The results showed that the modified phase change material microcapsules have broad prospects in the field of building material temperature control.

Bio‐based rigid polyurethane foam composites reinforced with flame retardants: From synthesis to performance evaluation

AbstractThe building and construction industry is under increasing pressure to make insulation materials greener, more sustainable, and less flammable. In this study, sugar beet pulp was liquified under the optimized liquefaction conditions and used as the source of bio‐polyol (SBpol) in the production of bio‐based rigid polyurethane foam (sPUF). In order to improve the flame retardancy, sPUF composites were prepared with the addition of flame retardants; expandable graphite (EG) and/or dimethyl methyl phosphonate (DMMP). The bio‐polyol was used at a fixed ratio of 50 php in sPUF composites whereas the total ratio of flame retardants was fixed at 20 php. The effects of the ratio of EG and/or DMMP on the morphological, physicomechanical, thermal, and flame retardant properties of sPUF composites were evaluated. Although the thermal conductivity values of flame retardant added sPUF composites were increased in comparison to the petroleum‐based foam, the compressive strength values were decreased as the amount of DMMP increased in the flame retardant formulation. Thermogravimetric analysis showed that the onset of decomposition of 20 php DMMP‐containing sPUF composite decreased to 168.3°C. Although the limiting oxygen index (LOI) value of the petroleum‐based PUF was as low as 19.7%, the LOI value of the sPUF/10E/10D foam increased to 24.9% (by about 26%). According to the cone calorimeter results, the peak heat release rate (pHRR) of sPUF was much higher than the petroleum‐based foam. The incorporation of both DMMP and EG could further improve the flame retardant properties. The pHRR value of sPUF/10E/10D was 28.1% lower than that of sPUF. The results have shown that flame retardancy of sPUF composites could be improved by the addition of EG which acts in the condensed phase and DMMP, which acts mainly in the gas phase during burning. Flame retardant incorporated sPUF composites are considered as promising materials for use in insulation applications.

What to do with polyurethane waste? The environmental potential of chemically recycling polyurethane rigid foam

The environmental potential guides through the maze of chemical recycling of polyurethane rigid foams highlighting promising options.

Sound-absorbing and thermal insulating properties of natural coir/jute hybrid composites for functional materials

A composite designed for soundproofing integrates both sound absorption materials and thermal insulation, combining the benefits of both into a single product. The absorption component serves to dissipate energy within the system, while the noise barrier reduces the transmission of sound. This study focuses on experimentally assessing the sound absorption coefficients of hybrid composite materials composed of coir and jute fibers, reinforced with epoxy resin, using compression molding techniques. Six different composite samples were prepared with varying blend proportions of these fibers: S1 Coir/100, S2 Jute/100, S3 Coir/Jute 50/50, S4 Coir/Jute 70/30, S5 Coir/Jute 30/70, and S6 Coir/Jute 60/40, following the standards set by the American Society for Testing and Materials (ASTM). The physical and morphological properties of the samples were examined using a Scanning Electron Microscope (SEM), while the sound absorption coefficients (SAC) were measured via the impedance tube method, following ASTM E (1050), and Thermal insulation values were measured according to Lee’s disk method (ASTM C177). The experimental results show the thermal resistance performances of natural fiber composites based on coir/jute fiber materials, is S5 C/J (0.156 W/mK) and S6 C/J (0.146 W/mK), and there is an improvement in thermal conductivity when compared to the rigid polyurethane foam, which is one of the most efficient thermal insulators. Across frequencies ranging from 1600 to 5000 Hz. The results indicated that the composite sample S4 C/J exhibited exceptional performance in absorbing high-frequency sound waves, particularly above 2500 Hz. Furthermore, it was observed that increasing the thickness of the S6 C/J composite could significantly enhance its sound absorption coefficient at medium and low frequencies. These findings underscore the potential of coir and jute fiber-based composites as effective sound-absorbing materials. Notably, these composites exhibit sound absorption coefficients exceeding 0.83%, showcasing their promising acoustic properties. Additionally, the utilization of natural fibers such as coir and jute, sourced from renewable materials, offers advantages of affordability, biodegradability, and recyclability, making them sustainable choices for soundproofing and thermal insulating materials.

An application performance study of monoisopropanolamine carbonate in refrigerator insulation materials

Monoisopropanolamine carbonate is a green, safe, and environmentally friendly non-chlorofluorinated polyurethane chemical foaming agent (CFA-1) that can react directly and rapidly with isocyanate to release carbon dioxide for foaming purposes. In this study, we investigated a mixed system of CFA-1, 1,1,1,3,3-pentafluoropropane (HFC-245fa), and cyclopentane (CP) to evaluate its foaming flow performance in refrigerator insulation material applications. We also examined various performance indicators of the resulting foam materials, such as compressive strength, closed cell ratio, and thermal conductivity. The experimental results demonstrated that by adding CFA-1 as a foaming agent, the density and dimensional stability of the foam were comparable to those achieved with the CP + water or CP + HFC-245fa system. In addition, there was a slight improvement in the closed cell ratio and compressive strength, which led to a reduction in the cell diameter within the CP + CFA-1 foaming system compared with those in both CP + water (28.79% decrease) and CP + HFC-245fa (26.11% decrease) systems. This optimized foam material exhibited an enhanced thermal insulation performance, with a 4.20% lower thermal conductivity compared to the CP + water system and 1.88% compared to the CP + HFC-245fa system. Replacing the HFC-245fa physical blowing agent with CFA-1 to prepare low-energy refrigerator insulation materials using rigid polyurethane foam technology offers significant benefits, including eliminating chlorofluorocarbon usage while reducing greenhouse gas emissions.

Preparation and fire resistance modification on tannin-based non-isocyanate polyurethane (NIPU) rigid foams

Non-isocyanate polyurethane (NIPU) as a new type of polyurethane material has become a hot research topic in the polyurethane industry due to its no utilization of toxic isocyanates during the synthesis process. And the developing on recyclable biomass materials has also much attention in the industrial sector, hence the preparation and application of bio-based NIPU has also become a very meaningful study work. So, in this paper, tannin as a biomass material was used to synthesize tannin based non-isocyanate polyurethanes (TNIPU) resin, and then successfully prepared a self-blowing TNIPU foam at room temperature by using formic acid as initiator and glutaraldehyde as cross-linking agent. The compressive strength of this foam as high as 0.8 MPa, which is an excellent compressive performance. Meanwhile it will return to the state before compression when removing the pressure. This indicating that the foam has good toughness. In addition, formic acid can react with the amino groups in TNIPU to form amide substances, and generated enough heat to initiate the foaming process. Glutaraldehyde, as a crosslinking agent, reacts with the amino group in TNIPU to form a network structure system. By scanning electron microscope (SEM) observation of the cell shapes, it can be seen that the foam cells were uniform in size and shape, and the cell pores showed open and closed cells. The limiting oxygen index (LOI) tested value of this TNIPU foam is 24.45 % without any flame retardant added, but compared to the LOI value of polyurethane foam (17 %–19 %), TNIPU foam reveal a better fire resistance. It has a wider application prospect.