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Surfactant in different formulations.
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Rigid polyurethane foams are one of the most important cellular plastics. Castor oil was modi-fied with glycerol to form the polyol and reacted with methyl diisocyanate and different proportions of silicon oil to achieve rigid polyurethane foam. Prepared foam was tested for its density and mechanical properties. It was found that compressive and fl...
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Citations
... Raminder Kaur et al. modified castor oil with glycerol to create a polyol, improving the compressive and flexural strength of PU foam. The addition of silicon oil reduced cell size, increasing foam density [19]. The castor oil-based PU foams encompass various industries, making it an appealing choice for eco-friendly product development. ...
This research explores the production of flexible polyurethane foam using castor oil with varying densities, treated via dip coating with sodium silicate and hydrochloric acid to form a protective silica hydrogel. This treatment enhances the foam’s acoustic and fire resistance properties. The sound absorption coefficient (SAC) is measured using an impedance tube per ASTM E 1050-12, and the noise reduction coefficient (NRC) is calculated. Specimen S5 shows superior performance with an NRC of 0.336 for coated and 0.283 for non-coated conditions, a significant 19% improvement. TGA revealed that non-coated foam showed initial sublimation at 240 °C and substantial degradation with a 75% weight loss at 400 °C, while coated samples like S5 began to decay at 300 °C, showing only a 25% weight reduction at 400 °C. These results highlight the influence of foam density on acoustic enhancement, making the foam ideal for automotive interiors by providing a quieter and safer environment for passengers.
... When the foam stabilizer dosage was 4%, the optimal compressive strength was 349 kPa, and the density was 0.063 g cm −3 . Kaur et al. found that when an appropriate amount of silicone oil was added, it was observed that the pores in PU foam became more uniform and reduced collapse [38]. Therefore, a stabilizer dosage of 4% was selected as the optimal result for this experiment. ...
Currently, polyurethane (PU) products are heavily dependent on petroleum resources, highlighting an urgent need to develop new bio-based materials. This study aimed to develop a sustainable method of utilizing low-cost and renewable xylose residues (XR) and crude glycerol (CG) for the production of biopolyols. Optimal synthesis conditions were determined to be 220 °C, 3 h, and 7% sodium hydroxide loading, resulting in biopolyols with a hydroxyl number of 505 mg KOH/g and an acid number of 1.7 mg KOH/g. The obtained biopolyols were used to produce biobased PU foams with a compressive strength of 225 kPa, density of 0.048 g cm⁻³, and thermal conductivity of 0.0355 W m⁻¹ K⁻¹. Characterization analysis using FT-IR, ¹H NMR, and TGA confirmed the excellent thermal stability and insulation properties of the bio-based PU foam. This study provides a valuable method for producing sustainable bio-based PU foam from XR and CG, thereby presenting a novel approach to realizing the high-value utilization of both resources.
Graphical Abstract
... Vegetable oil is the most often used renewable resource to generate precursors for PU products, since it is widely accessible [3,4]. Although these renewable sources have successfully yielded polyols, multiple studies have been carried out to incorporate various fillers and anti-flaming chemicals into these foams to enhance their anti-flammable, thermal, and mechanical abilities [5][6][7][8][9][10][11][12]. In addition, as the toxic polyisocyanates used to make PU could be dangerous to humans, researchers are seeking a green and sustainable route of producing PUs from renewable sources, without the use of polyisocyanates [3]. ...
Self-blowing non-isocyanate polyurethane foams have been synthesized by reacting xylose with dimethyl carbonate and hexamethylene diamine using citric acid as a natural crosslinker via the process of transurethanisation. The resulting foams exhibit exceptional flame retardancy in comparison to conventional PU foams. The structure of the foam cells was examined using scanning electron microscopy. Solid-state NMR and infrared spectroscopy were used to analyze the functional groups present in the products formed. The formation of the urethane bridge was confirmed by the emergence of peaks at 158.24 ppm and 1693 cm− 1 respectively. The thermal properties were evaluated by using TGA and DSC, which further indicated a glass transition temperature of around 112.82 °C. The dependence of viscosity of polymeric solutions on the different shear rates was also studied using a parallel plate rheometer. Limiting Oxygen Index was employed to study the flammability of the prepared foams, and it was observed that they exhibit considerable fire resistance (26.9%),which is quite comparable to the fire resistance offered by the isocyanate-based polyurethane foams with added fire retardants. The diffraction pattern of the prepared NIPU was analyzed by PXRD.
... Furniture and Bedding: Polyurethanes are widely employed in furniture and beddings [79]. Flexible polyurethane foams are generally used for cushioning purposes, as their density can be adjusted according to the requirement of the users. ...
Among numerous synthetic macromolecules, polyurethane in its different forms has proven its sheer dominance and established a reputation as a reliable and trusted material due to its proficiency in terms of superior properties, which include: high mechanical strength and abrasion resistance, good durability, good adhesion, good thermal stability, excellent chemical and weathering resistance. Synthetic polyurethane materials are non-biodegradable, poisonous, and use petrochemical-based raw materials, which are now depleting, leading to a surge in polyurethane production costs. Bio-based polyurethanes (PU) have been synthesized by researchers in recent decades and have mostly overtaken petrochemical-based PU in terms of challenges such as solid pollution, economic effectiveness, and availability of raw materials. Enormous kinds of available bio-renewable sources as predecessors for the production of polyols and isocyanates have been explored for the development of “greener” PU materials; these bio-based polyurethanes have significant potential to be used as future PU products, with a partial or total replacement of petroleum-based polyurethanes, due to increasing concern about the environment, their relatively low cost and biodegradability. This critical review concentrates on the possibilities of renewable sources to be used for polyurethane production and gives a clear perspective on the journey, utilization, and recent advancements in the field of different bio-based polyurethane polymers that have arisen over the last decade.
... First, the castor oil was modified to obtain polyol according to the procedure reported in prior studies. [13][14][15] Then all the components, as per the experimental design strategy, were added into a beaker and stirred at room temperature for the adequate mixing. The prepared mixture was spread into a pre-lubricated metal mould (200 × 200 × 100 mm) and left to stand for 96 h, for complete curing. ...
In the present study, Taguchi design of experiments (DOEs) L 18 orthogonal array has been used for the investigation of the mechanical behavior of rigid polyurethane foam (RPUF) composites. The outcome of the process parameters such as polyol, filler, surfactant, catalyst, blowing agent, and anti-flaming agent on the mechanical properties, such as tensile, flexural, and compressive strengths and hardness (Shore D) of RPUF composites, has been examined, and the resulted data were analyzed by means of Taguchi design of experiments. The raw data for the average values of the mechanical properties and the signal-to-noise (S/N) ratio for each parameter were evaluated at three levels, and the analysis of variance (ANOVA) and optimum process parameters are determined. The confirmation experiments were performed for the validation of the improved performance and to measure the contribution of individual parameter on the responses. The confirmation experiments revealed the average tensile strength, average compressive strength, average flexural strength, and average hardness (Shore D) as 5.24 MPa, 6.37 MPa, 12.28 MPa, and 72.43, respectively, which fall within the 95% confidence interval of the anticipated optimum process parameters.
... 5,22,24,25 The main properties of PU foams are attributed to the density and morphological structure, which are influenced by the concentrations of polyol and isocyanate, resulting in different foam structures (flexible, semi-flexible, or rigid). 10,22,23,[26][27][28][29] About 60-70% of the polyurethane properties are defined by the reagents employed. 30 The polyol from the castor oil allows flexible segments, which gives extensibility, while the chain extensor and isocyanates originate rigid segments that act as physical crosslinks. ...
This study evaluates the efficiency of castor oil–based polyurethane foams for oil sorption S10 and S500, focusing on the influence of the pores’ size. Different foams were produced by varying the polyol: isocyanate ratio (1:0.3; 1:0.5; 1:1.0; 1:1.5; and 1:2.0). The physicochemical properties, morphology, density, and Hg porosity were determined. The sorption capacity was influenced by exposure time, oil viscosity, and concentration of the reagents, considering variations in the hydrophobicity, void content, and morphology. The results showed that the foam produced at an in the same mass proportion (PU C ) has a higher sorption capacity in exposure time from 25 to 40 h due to higher void content and larger pore diameter size. It was observed that the lower viscosity of S10 diesel contributes to the higher sorption efficiency compared to S500 one. The Taguchi method corroborated the mentioned results, indicating a higher sorption trend by varying the reagent concentration and exposure times.
... The scientific works focused on environmentally-friendly substrates used for the polyurethane production are actually related with bio-based polyols, bioglycols and the methods of their synthesis [1][2][3][4][5][6][7][8]. However, in the case of bio-based isocyanates or more environment-friendly methods of PU production are not so common [9]. ...
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.
... Because of their excellent properties and the possibilities of obtaining them with the usage of bio-based monomers, these materials are an issue in a lot of research papers. Special attention was given to PU materials synthesized using renewable sources such as vegetable oils and polysaccharides [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] or products of polyurethanes recycling known as recovered polyols obtaining in glycerolysis [18] or glycolysis [19][20][21] processes. Unfortunately, the application of alternative monomers does not always lead to producing polyurethane materials fully derived from environment-friendly monomers or materials with good mechanical properties. ...
Bio-based polymeric materials and green routes for their preparation are current issues of many research works. In this work, we used the diisocyanate mixture based on partially bio-based diisocyanate origin and typical petrochemical diisocyanate for the preparation of novel bio-based thermoplastic polyurethane elastomers (bio-TPUs). We studied the influence of the diisocyanate mixture composition on the chemical structure, thermal, thermomechanical, and mechanical properties of obtained bio-TPUs. Diisocyanate mixture and bio-based 1,4-butanediol (as a low molecular chain extender) created bio-based hard blocks (HS). The diisocyanate mixture contained up to 75 wt % of partially bio-based diisocyanate. It is worth mentioning that the structure and amount of HS impact the phase separation, processing, thermal or mechanical properties of polyurethanes. The soft blocks (SS) in the bio-TPU’s materials were built from α,ω-oligo(ethylene-butylene adipate) diol. Hereby, bio-TPUs differed in hard segments content (c.a. 30; 34; 40, and 53%). We found that already increase of bio-based diisocyanate content of the bio-TPU impact the changes in their thermal stability which was measured by TGA. Based on DMTA results we observed changes in the viscoelastic behavior of bio-TPUs. The DSC analysis revealed decreasing in glass transition temperature and melting temperature of hard segments. In general, obtained materials were characterized by good mechanical properties. The results confirmed the validity of undertaken research problem related to obtaining bio-TPUs consist of bio-based hard building blocks. The application of partially bio-based diisocyanate mixtures and bio-based chain extender for bio-TPU synthesis leads to sustainable chemistry. Therefore the total level of “green carbons” increases with the increase of bio-based diisocyanate content in the bio-TPU structure. Obtained results constitute promising data for further works related to the preparation of fully bio-based thermoplastic polyurethane elastomers and development in the field of bio-based polymeric materials.
... The use of natural fibers also reduces the cost, light weight, environmental friendly, renewable and sustainable resources [2,5,6]. The addition of natural fibers into polymer matrix can produce polymer matrix composites with good properties such as mechanical properties, improved surface finish of molded parts composite, flexibility during processing and low hazardous, while decrease the thermal stability [5,7,8]. However, the main disadvantages of natural fibers in polymer composites are the relative high moisture absorption, poor compatibility between fibers and matrix and hydrophilic nature causes the fibers to swell [9]. ...
Polyurethane (PU) foam were produced from polyol (PolyGreen R3110) and 4,4- diphenylmethane diisocyanate (Maskiminate 80) with distilled water as a blowing agent. Natural fibers have received more attention from researchers due to their ability to increase the properties of the polymer composites. In this work, PU/Henna foam composites were prepared by used Henna fibers at different loading of 5, 10, 15 and 20 wt. %. The effect of different Henna loading on PU foam were investigated by density, compression test, morphology and water absorption. Core density of PU/Henna foam composites increased with addition Henna compared to control PU and showed highest core density of 85.10 kgm ⁻³ . Compressive strength decreased to 0.53 MPa after Henna addition at 5 % PU/Henna foam composites. Henna addition to 20 % PU/Henna foam composites were reduced the compressive strength to 0.97 MPa due to stiffness effect of Henna that contributed to embrittlement of the cell wall. The distorted cell wall and less uniform of cell structure were proved by SEM due to Henna addition as compared to control PU. Water absorption percentage of PU/Henna foam composites were increased with Henna addition as compared to control PU. It is because hydrophilic properties of Henna tendency to absorb moisture.
... Melamine (2,4,6-Triamino-1,3,5-triazine), Tris(2chloroethyl) phosphate (TCP) and Tris(1,3-dichloro-2-propylphosphate) (TDCPP) on the properties of RPUFs. The RPUFs developed in the given study have been derived from a plant source i.e. castor oil, the properties of which are studied and reported earlier by the some researchers [20][21][22][23][24][25][26][27] and other investigators and found to be comparable with commercial petrochemical based RPUFs. ...
... A two-step process was used to prepare the anti-flammable RPUFs. Castor oil was modified by transesterification process in the first step to get polyol (Mpol) according to the procedure reported in prior studies [24][25][26]. Glycerol was used to enhance the hydroxyl value of castor oil by introducing more hydroxyl groups. The modification of the castor oil was performed under the inert atmosphere of nitrogen using 2:1 ratio of the castor oil to the glycerol at the temperature 180°C-210°C for 4-5 h, till a hydroxyl value of 390-410 mg KOH g −1 is achieved. ...
The major drawback in the use of Rigid Polyurethane Foam (RPUF) is its high flammability which limits is industrial applications. In the presented studies, RPUF was incorporated with different antiflamming agents such as Melamine (2,4,6-Triamino-1,3,5-triazine), Tris(1,3-dichloro-2-propylphosphate) (TDCPP) and Tris(2-chloroethyl) phosphate (TCP). Unlike the conventional RPUF, the foam developed here is derived from vegetable oil based polyol i.e. from Castor oil. Flammability of resulted RPUFs was tested according to UL 94 V test. The structure of the resulted foam samples was characterized by FTIR, XRD and SEM and their thermal properties were studied by TGA. The mechanical behaviour i.e. Tensile, compressive and flexural strength and hardness was examined by universal testing machine. The investigations made on flammability, mechanical and thermal properties of RPUFs incorporated with melamine, TCP, and TDCPP, suggested that, among all samples prepared, TDCPP incorporated RPUF rendered good thermal stability, mechanical and flame retardant properties. Results obtained from SEM analysis also revealed the reduction in the cell size in case of TDCPP based RPUFs.
